feat(js_analyze): implement noDuplicateEnumValues

[Netail]

Summary

Port Eslint Typescript's no-duplicate-enum-values which disallows defining an enum with multiple members initialized to the same value.

Test Plan

Added unit tests covering all scenarios

Docs

https://typescript-eslint.io/rules/no-duplicate-enum-values/

[changeset-bot]

🦋 Changeset detected

Latest commit: 2708542

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 13 packages

Name	Type
@biomejs/biome	Patch
@biomejs/cli-win32-x64	Patch
@biomejs/cli-win32-arm64	Patch
@biomejs/cli-darwin-x64	Patch
@biomejs/cli-darwin-arm64	Patch
@biomejs/cli-linux-x64	Patch
@biomejs/cli-linux-arm64	Patch
@biomejs/cli-linux-x64-musl	Patch
@biomejs/cli-linux-arm64-musl	Patch
@biomejs/wasm-web	Patch
@biomejs/wasm-bundler	Patch
@biomejs/wasm-nodejs	Patch
@biomejs/backend-jsonrpc	Patch

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Click here if you're a maintainer who wants to add another changeset to this PR

[coderabbitai]

Walkthrough

Adds a new nursery lint rule noDuplicateEnumValues for TypeScript enums that detects enum members initialised with identical values (numbers, strings, or single-template expressions). Implements the rule, diagnostics, examples and tests in crates/biome_js_analyze, adds test fixtures for valid and invalid cases, exposes an empty NoDuplicateEnumValuesOptions struct and its module in crates/biome_rule_options, and adds a changelog entry in .changeset/orange-news-sink.md.

Suggested reviewers

• ematipico
• dyc3

🚥 Pre-merge checks | ✅ 2

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarises the main change: implementing a new noDuplicateEnumValues lint rule for the JavaScript analyser.
Description check	✅ Passed	The description is directly related to the changeset, explaining that it ports ESLint TypeScript's no-duplicate-enum-values rule and mentions unit tests were added.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing touches

• 📝 Generate docstrings

---

📜 Recent review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 772973a and 2708542.

⛔ Files ignored due to path filters (2)

• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts.snap is excluded by !**/*.snap and included by **

📒 Files selected for processing (3)

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts

🚧 Files skipped from review as they are similar to previous changes (1)

• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts

🧰 Additional context used

📓 Path-based instructions (1)

**/*.rs

📄 CodeRabbit inference engine (CONTRIBUTING.md)

**/*.rs: Use inline rustdoc documentation for rules, assists, and their options
Use the dbg!() macro for debugging output in Rust tests and code
Use doc tests (doctest) format with code blocks in rustdoc comments; ensure assertions pass in tests

Files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

🧠 Learnings (24)

📓 Common learnings

Learnt from: dyc3
Repo: biomejs/biome PR: 8639
File: crates/biome_js_analyze/src/lint/nursery/no_excessive_lines_per_file.rs:101-108
Timestamp: 2025-12-31T15:35:41.261Z
Learning: In crates/biome_analyze/**/*analyze/src/lint/nursery/**/*.rs, the `issue_number` field in `declare_lint_rule!` macro is optional and the vast majority of nursery rules do not need it. Do not recommend adding `issue_number` unless there's a specific reason.

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : New rules must be placed inside the `nursery` group before promotion to other groups

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Apply `#[serde(deny_unknown_fields)]` to rule option structs to enforce strict configuration validation

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Use `Option<_>` wrapper for rule option fields to enable proper merging of configurations

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule names should use the `no` prefix when the rule's sole intention is to forbid a single concept

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `declare_lint_rule!` macro with a `version` field set to `next` for new rules

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Invalid code snippets in rule documentation must emit exactly one diagnostic

Learnt from: dyc3
Repo: biomejs/biome PR: 8171
File: crates/biome_js_analyze/src/lint/nursery/no_leaked_render.rs:125-137
Timestamp: 2025-11-21T01:10:53.059Z
Learning: In the Biome codebase, each lint rule has its own options type declaration (e.g., `type Options = RuleNameOptions`) as part of the codegen process, even if the options struct is empty or unused. This is standard practice and should not be flagged as an issue.

Learnt from: ematipico
Repo: biomejs/biome PR: 8537
File: crates/biome_js_analyze/src/lint/nursery/no_leaked_render.rs:167-210
Timestamp: 2025-12-22T09:27:13.161Z
Learning: In crates/biome_analyze/**/*analyze/src/**/*.rs, the `fix_kind` field in `declare_lint_rule!` should only be specified when the rule implements the `action` function. Rules that only emit diagnostics without providing code fixes should not include `fix_kind` in their metadata.

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Rule options must be defined in the `biome_rule_options` crate with a file named after the rule

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/tests/specs/**/* : Create test files with `invalid` and `valid` prefixes to represent code that should and should not trigger the rule

Applied to files:

• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts

📚 Learning: 2025-12-04T13:29:49.287Z

Learnt from: dyc3
Repo: biomejs/biome PR: 8291
File: crates/biome_html_formatter/tests/specs/prettier/vue/html-vue/elastic-header.html:10-10
Timestamp: 2025-12-04T13:29:49.287Z
Learning: Files under `crates/biome_html_formatter/tests/specs/prettier` are test fixtures synced from Prettier and should not receive detailed code quality reviews (e.g., HTTP vs HTTPS, formatting suggestions, etc.). These files are test data meant to validate formatter behavior and should be preserved as-is.

Applied to files:

• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts

📚 Learning: 2025-11-24T18:04:57.309Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_diagnostics/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:04:57.309Z
Learning: Applies to crates/biome_diagnostics/**/*.rs : Use #[derive(Diagnostic)] on enums when every variant contains a type that is itself a diagnostic

Applied to files:

• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts
• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Invalid code snippets in rule documentation must emit exactly one diagnostic

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `declare_lint_rule!` macro with a `version` field set to `next` for new rules

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : New rules must be placed inside the `nursery` group before promotion to other groups

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-12-31T15:35:32.899Z

Learnt from: dyc3
Repo: biomejs/biome PR: 8639
File: crates/biome_js_analyze/src/lint/nursery/no_excessive_lines_per_file.rs:101-108
Timestamp: 2025-12-31T15:35:32.899Z
Learning: In Rust lint rules under the nursery category, the issue_number field in declare_lint_rule! is optional and should not be added unless there is a compelling reason. In code reviews, verify that no unnecessary issue_number is included in nursery lint declarations. Only add issue_number if there is an explicit, justified reason (e.g., tracked issue for external observers). This guidance broadly applies to all nursery lint rule files, not just the single file.

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Deprecated rules must include a `deprecated` field in the `declare_lint_rule!` macro with an explanation of what rule to use instead

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : When porting rules from other linters, use `sources` metadata with `RuleSource::Eslint().same()` for identical behavior or `.inspired()` for different behavior

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-12-22T09:26:56.943Z

Learnt from: ematipico
Repo: biomejs/biome PR: 8537
File: crates/biome_js_analyze/src/lint/nursery/no_leaked_render.rs:167-210
Timestamp: 2025-12-22T09:26:56.943Z
Learning: When defining lint rules (declare_lint_rule!), only specify fix_kind if the rule implements an action(...) function. Rules that only emit diagnostics without a code fix should omit fix_kind. This applies to all Rust lint rule definitions under crates/.../src/lint (e.g., crates/biome_js_analyze/src/lint/...).

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule names should use the `no` prefix when the rule's sole intention is to forbid a single concept

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Mark rules with `issue_number` in the `declare_lint_rule!` macro if they are work-in-progress to indicate missing features

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use the `Semantic<T>` query type to access semantic information about bindings, references, and scope within a rule

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use the `try operator (?)` to transform `Result` types into `Option` when the `run` function returns `Option`

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:05:27.810Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_js_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:05:27.810Z
Learning: Applies to crates/biome_js_formatter/**/*.rs : Do not attempt to 'fix' the code; if a token/node is known to be mandatory but is missing, return `None` instead

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Code blocks in rule documentation must specify a language identifier and be tagged with `expect_diagnostic` for invalid examples or remain untagged for valid examples

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:06:03.545Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_parser/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:06:03.545Z
Learning: Applies to crates/biome_parser/**/src/**/*.rs : Use `p.eat(token)` for optional tokens, `p.expect(token)` for required tokens, `parse_rule(p).ok(p)` for optional nodes, and `parse_rule(p).or_add_diagnostic(p, error)` for required nodes

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : The first paragraph of rule documentation must be written in a single line to ensure proper rendering in the rules overview table

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Implement custom `Queryable` and `Visitor` types for rules that require deep inspection of child nodes to avoid inefficient traversals

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule documentation must include an `## Examples` section followed by `### Invalid` and `### Valid` subsections, with Invalid appearing first

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-21T01:10:53.059Z

Learnt from: dyc3
Repo: biomejs/biome PR: 8171
File: crates/biome_js_analyze/src/lint/nursery/no_leaked_render.rs:125-137
Timestamp: 2025-11-21T01:10:53.059Z
Learning: In the Biome codebase, each lint rule has its own options type declaration (e.g., `type Options = RuleNameOptions`) as part of the codegen process, even if the options struct is empty or unused. This is standard practice and should not be flagged as an issue.

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `.ok()?` to transform `Result` types into `Option` or `let else` pattern to handle errors when the function returns `Vec`

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Implement the `run` function to return `Option<Self::State>` or `Vec<Self::State>` (as `Box<[Self::State]>`) depending on whether the rule reports one or multiple signals

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

🧬 Code graph analysis (1)

crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs (1)

crates/biome_analyze/src/rule.rs (3)

• recommended (625-628)
• sources (640-643)
• same (255-260)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (13)

• GitHub Check: Test Node.js API
• GitHub Check: Lint project (depot-windows-2022)
• GitHub Check: Check Dependencies
• GitHub Check: Test (depot-ubuntu-24.04-arm-16)
• GitHub Check: Lint project (depot-ubuntu-24.04-arm-16)
• GitHub Check: Test (depot-windows-2022-16)
• GitHub Check: Documentation
• GitHub Check: Check JS Files
• GitHub Check: autofix
• GitHub Check: Bench (biome_js_formatter)
• GitHub Check: Bench (biome_js_analyze)
• GitHub Check: Bench (biome_js_parser)
• GitHub Check: Bench (biome_configuration)

🔇 Additional comments (5)

crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts (1)

1-23: Excellent test coverage for valid cases.

The fixture covers numeric values, string literals with various quote styles, mixed types, and auto-incremented members. All cases correctly represent enums that should not trigger the rule.

crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs (4)

13-62: Well-structured rule declaration.

The documentation follows all required conventions: single-line first paragraph, proper examples structure with invalid cases first, and correct metadata (version: "next", appropriate source attribution).

---

156-177: Clear and helpful diagnostics.

The multi-range diagnostic correctly highlights the first duplicate with a primary message and annotates additional occurrences with detail labels, plus an explanatory note.

---

180-184: Appropriate internal representation.

Using string-based comparison for both numeric and string values ensures consistent hashing and equality checks within the HashSet.

---

127-141: Verify template literal value handling.

The to_trimmed_string() method on line 137 requires confirmation of its behaviour. If it trims whitespace from the content (rather than just template syntax), template literals like ` hello ` and `hello` would be incorrectly treated as duplicates instead of distinct values. Manual inspection of the method implementation is needed to confirm it preserves interior whitespace.

---

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Actionable comments posted: 1

📜 Review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between a1914d4 and 751e7ee.

⛔ Files ignored due to path filters (8)

• crates/biome_cli/src/execute/migrate/eslint_any_rule_to_biome.rs is excluded by !**/migrate/eslint_any_rule_to_biome.rs and included by **
• crates/biome_configuration/src/analyzer/linter/rules.rs is excluded by !**/rules.rs and included by **
• crates/biome_diagnostics_categories/src/categories.rs is excluded by !**/categories.rs and included by **
• crates/biome_js_analyze/src/lint/nursery.rs is excluded by !**/nursery.rs and included by **
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts.snap is excluded by !**/*.snap and included by **
• packages/@biomejs/backend-jsonrpc/src/workspace.ts is excluded by !**/backend-jsonrpc/src/workspace.ts and included by **
• packages/@biomejs/biome/configuration_schema.json is excluded by !**/configuration_schema.json and included by **

📒 Files selected for processing (6)

• .changeset/orange-news-sink.md
• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts
• crates/biome_rule_options/src/lib.rs
• crates/biome_rule_options/src/no_duplicate_enum_values.rs

🧰 Additional context used

📓 Path-based instructions (1)

**/*.rs

📄 CodeRabbit inference engine (CONTRIBUTING.md)

**/*.rs: Use inline rustdoc documentation for rules, assists, and their options
Use the dbg!() macro for debugging output in Rust tests and code
Use doc tests (doctest) format with code blocks in rustdoc comments; ensure assertions pass in tests

Files:

• crates/biome_rule_options/src/lib.rs
• crates/biome_rule_options/src/no_duplicate_enum_values.rs
• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

🧠 Learnings (27)

📓 Common learnings

Learnt from: dyc3
Repo: biomejs/biome PR: 8171
File: crates/biome_js_analyze/src/lint/nursery/no_leaked_render.rs:125-137
Timestamp: 2025-11-21T01:10:53.059Z
Learning: In the Biome codebase, each lint rule has its own options type declaration (e.g., `type Options = RuleNameOptions`) as part of the codegen process, even if the options struct is empty or unused. This is standard practice and should not be flagged as an issue.

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Use `Option<_>` wrapper for rule option fields to enable proper merging of configurations

Applied to files:

• crates/biome_rule_options/src/lib.rs
• crates/biome_rule_options/src/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Rule options must be defined in the `biome_rule_options` crate with a file named after the rule

Applied to files:

• crates/biome_rule_options/src/lib.rs
• crates/biome_rule_options/src/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Apply `#[serde(deny_unknown_fields)]` to rule option structs to enforce strict configuration validation

Applied to files:

• crates/biome_rule_options/src/lib.rs
• crates/biome_rule_options/src/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:05:42.356Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_js_type_info/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:05:42.356Z
Learning: Applies to crates/biome_js_type_info/**/*.rs : No module may copy or clone data from another module in the module graph, not even behind an `Arc`

Applied to files:

• crates/biome_rule_options/src/lib.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Implement `biome_deserialize::Merge` for rule option types to define how shared and user configurations are merged

Applied to files:

• crates/biome_rule_options/src/lib.rs
• crates/biome_rule_options/src/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Rule option types must derive `Deserializable`, `Serialize`, `Deserialize`, and optionally `JsonSchema` traits

Applied to files:

• crates/biome_rule_options/src/lib.rs
• crates/biome_rule_options/src/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Apply `#[serde(rename_all = "camelCase")]` to rule option structs to match JSON configuration naming convention

Applied to files:

• crates/biome_rule_options/src/lib.rs
• crates/biome_rule_options/src/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Use `Box<[Box<str>]>` instead of `Vec<String>` for collections of strings in rule options to save memory

Applied to files:

• crates/biome_rule_options/src/lib.rs

📚 Learning: 2025-11-21T01:10:53.059Z

Learnt from: dyc3
Repo: biomejs/biome PR: 8171
File: crates/biome_js_analyze/src/lint/nursery/no_leaked_render.rs:125-137
Timestamp: 2025-11-21T01:10:53.059Z
Learning: In the Biome codebase, each lint rule has its own options type declaration (e.g., `type Options = RuleNameOptions`) as part of the codegen process, even if the options struct is empty or unused. This is standard practice and should not be flagged as an issue.

Applied to files:

• crates/biome_rule_options/src/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:04:57.309Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_diagnostics/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:04:57.309Z
Learning: Applies to crates/biome_diagnostics/**/*.rs : Use #[derive(Diagnostic)] on enums when every variant contains a type that is itself a diagnostic

Applied to files:

• crates/biome_rule_options/src/no_duplicate_enum_values.rs
• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : New rules must be placed inside the `nursery` group before promotion to other groups

Applied to files:

• .changeset/orange-news-sink.md
• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-12-21T21:15:03.796Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: CONTRIBUTING.md:0-0
Timestamp: 2025-12-21T21:15:03.796Z
Learning: For new nursery rules, send PRs to the maintenance branch `main`

Applied to files:

• .changeset/orange-news-sink.md

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Invalid code snippets in rule documentation must emit exactly one diagnostic

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Deprecated rules must include a `deprecated` field in the `declare_lint_rule!` macro with an explanation of what rule to use instead

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `declare_lint_rule!` macro with a `version` field set to `next` for new rules

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : When porting rules from other linters, use `sources` metadata with `RuleSource::Eslint().same()` for identical behavior or `.inspired()` for different behavior

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule names should use the `no` prefix when the rule's sole intention is to forbid a single concept

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-12-22T09:26:56.943Z

Learnt from: ematipico
Repo: biomejs/biome PR: 8537
File: crates/biome_js_analyze/src/lint/nursery/no_leaked_render.rs:167-210
Timestamp: 2025-12-22T09:26:56.943Z
Learning: When defining lint rules (declare_lint_rule!), only specify fix_kind if the rule implements an action(...) function. Rules that only emit diagnostics without a code fix should omit fix_kind. This applies to all Rust lint rule definitions under crates/.../src/lint (e.g., crates/biome_js_analyze/src/lint/...).

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-12-31T15:35:32.899Z

Learnt from: dyc3
Repo: biomejs/biome PR: 8639
File: crates/biome_js_analyze/src/lint/nursery/no_excessive_lines_per_file.rs:101-108
Timestamp: 2025-12-31T15:35:32.899Z
Learning: In Rust lint rules under the nursery category, the issue_number field in declare_lint_rule! is optional and should not be added unless there is a compelling reason. In code reviews, verify that no unnecessary issue_number is included in nursery lint declarations. Only add issue_number if there is an explicit, justified reason (e.g., tracked issue for external observers). This guidance broadly applies to all nursery lint rule files, not just the single file.

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `declare_node_union!` macro to query multiple node types together to avoid redundant traversal passes

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Code blocks in rule documentation must specify a language identifier and be tagged with `expect_diagnostic` for invalid examples or remain untagged for valid examples

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Implement the `run` function to return `Option<Self::State>` or `Vec<Self::State>` (as `Box<[Self::State]>`) depending on whether the rule reports one or multiple signals

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule names should use the `use` prefix when the rule's sole intention is to mandate a single concept

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use the `Semantic<T>` query type to access semantic information about bindings, references, and scope within a rule

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/tests/specs/**/* : Create test files with `invalid` and `valid` prefixes to represent code that should and should not trigger the rule

Applied to files:

• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts

📚 Learning: 2025-12-04T13:29:49.287Z

Learnt from: dyc3
Repo: biomejs/biome PR: 8291
File: crates/biome_html_formatter/tests/specs/prettier/vue/html-vue/elastic-header.html:10-10
Timestamp: 2025-12-04T13:29:49.287Z
Learning: Files under `crates/biome_html_formatter/tests/specs/prettier` are test fixtures synced from Prettier and should not receive detailed code quality reviews (e.g., HTTP vs HTTPS, formatting suggestions, etc.). These files are test data meant to validate formatter behavior and should be preserved as-is.

Applied to files:

• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts

🧬 Code graph analysis (1)

crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs (2)

crates/biome_service/src/workspace.rs (1)

• markup (1195-1197)

crates/biome_analyze/src/rule.rs (3)

• recommended (625-628)
• sources (640-643)
• same (255-260)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (15)

• GitHub Check: Check JS Files
• GitHub Check: Validate rules documentation
• GitHub Check: autofix
• GitHub Check: Bench (biome_configuration)
• GitHub Check: Bench (biome_js_formatter)
• GitHub Check: Test Node.js API
• GitHub Check: Bench (biome_js_analyze)
• GitHub Check: Bench (biome_js_parser)
• GitHub Check: Test (depot-ubuntu-24.04-arm-16)
• GitHub Check: End-to-end tests
• GitHub Check: Check Dependencies
• GitHub Check: Documentation
• GitHub Check: Test (depot-windows-2022-16)
• GitHub Check: Lint project (depot-windows-2022)
• GitHub Check: Lint project (depot-ubuntu-24.04-arm-16)

🔇 Additional comments (9)

.changeset/orange-news-sink.md (1)

1-5: LGTM!

The changeset entry is well-formatted and clearly describes the new nursery rule.

crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts (2)

2-5: Good test case for numeric duplicates.

This correctly tests the detection of duplicate numeric enum values.

---

7-11: Excellent coverage of string literal variations.

Testing duplicate detection across double quotes, single quotes, and template literals is thorough.

crates/biome_rule_options/src/lib.rs (1)

62-62: LGTM!

Module declaration is correctly placed in alphabetical order.

crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts (2)

2-5: LGTM!

Valid test case for unique numeric enum values.

---

7-11: LGTM!

Valid test case ensuring unique string values with different quote styles don't trigger false positives.

crates/biome_rule_options/src/no_duplicate_enum_values.rs (1)

1-6: LGTM!

The options struct follows all coding guidelines with the correct derives and attributes. Based on learnings, empty options structs are standard practice for the codegen process.

crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs (2)

13-67: Rule declaration looks spot-on.

Correct use of version: "next", proper ESLint TypeScript source with .same(), and comprehensive documentation with expect_diagnostic tags. Nicely done.

---

133-154: Diagnostic generation is sound.

Good approach: first duplicate gets the primary message, subsequent ones are added as details, and the explanatory note ties it together. Clear and informative.

[codspeed-hq]

Merging this PR will not alter performance

✅ 58 untouched benchmarks
⏩ 95 skipped benchmarks¹

---

_{Comparing Netail:feat/no-duplicate-enum-values (2708542) with main (251b47b)}

Footnotes

1. 95 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In @crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs:
- Around line 85-90: The code incorrectly treats members without initializers by
using index.to_string() and inserting that into found, causing false duplicate
reports; update the logic in the block handling member.initializer() so that if
member.initializer() is None you simply continue (skip) before any use of index
or insertion into found—i.e., move the continue to immediately after the None
check and do not call found.insert(index.to_string()) or
duplicates.push(member.range()) for members lacking an initializer.

📜 Review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 751e7ee and 8974ab7.

⛔ Files ignored due to path filters (2)

• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts.snap is excluded by !**/*.snap and included by **

📒 Files selected for processing (3)

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts

🧰 Additional context used

📓 Path-based instructions (1)

**/*.rs

📄 CodeRabbit inference engine (CONTRIBUTING.md)

**/*.rs: Use inline rustdoc documentation for rules, assists, and their options
Use the dbg!() macro for debugging output in Rust tests and code
Use doc tests (doctest) format with code blocks in rustdoc comments; ensure assertions pass in tests

Files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

🧠 Learnings (19)

📓 Common learnings

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : New rules must be placed inside the `nursery` group before promotion to other groups

Learnt from: dyc3
Repo: biomejs/biome PR: 8639
File: crates/biome_js_analyze/src/lint/nursery/no_excessive_lines_per_file.rs:101-108
Timestamp: 2025-12-31T15:35:41.261Z
Learning: In crates/biome_analyze/**/*analyze/src/lint/nursery/**/*.rs, the `issue_number` field in `declare_lint_rule!` macro is optional and the vast majority of nursery rules do not need it. Do not recommend adding `issue_number` unless there's a specific reason.

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Invalid code snippets in rule documentation must emit exactly one diagnostic

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `declare_lint_rule!` macro with a `version` field set to `next` for new rules

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule names should use the `no` prefix when the rule's sole intention is to forbid a single concept

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/tests/specs/**/* : Create test files with `invalid` and `valid` prefixes to represent code that should and should not trigger the rule

Applied to files:

• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Invalid code snippets in rule documentation must emit exactly one diagnostic

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Deprecated rules must include a `deprecated` field in the `declare_lint_rule!` macro with an explanation of what rule to use instead

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : New rules must be placed inside the `nursery` group before promotion to other groups

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `declare_lint_rule!` macro with a `version` field set to `next` for new rules

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : When porting rules from other linters, use `sources` metadata with `RuleSource::Eslint().same()` for identical behavior or `.inspired()` for different behavior

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-12-31T15:35:32.899Z

Learnt from: dyc3
Repo: biomejs/biome PR: 8639
File: crates/biome_js_analyze/src/lint/nursery/no_excessive_lines_per_file.rs:101-108
Timestamp: 2025-12-31T15:35:32.899Z
Learning: In Rust lint rules under the nursery category, the issue_number field in declare_lint_rule! is optional and should not be added unless there is a compelling reason. In code reviews, verify that no unnecessary issue_number is included in nursery lint declarations. Only add issue_number if there is an explicit, justified reason (e.g., tracked issue for external observers). This guidance broadly applies to all nursery lint rule files, not just the single file.

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule names should use the `no` prefix when the rule's sole intention is to forbid a single concept

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-12-22T09:26:56.943Z

Learnt from: ematipico
Repo: biomejs/biome PR: 8537
File: crates/biome_js_analyze/src/lint/nursery/no_leaked_render.rs:167-210
Timestamp: 2025-12-22T09:26:56.943Z
Learning: When defining lint rules (declare_lint_rule!), only specify fix_kind if the rule implements an action(...) function. Rules that only emit diagnostics without a code fix should omit fix_kind. This applies to all Rust lint rule definitions under crates/.../src/lint (e.g., crates/biome_js_analyze/src/lint/...).

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Code blocks in rule documentation must specify a language identifier and be tagged with `expect_diagnostic` for invalid examples or remain untagged for valid examples

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule documentation must include an `## Examples` section followed by `### Invalid` and `### Valid` subsections, with Invalid appearing first

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use the `try operator (?)` to transform `Result` types into `Option` when the `run` function returns `Option`

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:05:27.810Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_js_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:05:27.810Z
Learning: Applies to crates/biome_js_formatter/**/*.rs : Do not attempt to 'fix' the code; if a token/node is known to be mandatory but is missing, return `None` instead

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:04:57.309Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_diagnostics/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:04:57.309Z
Learning: Applies to crates/biome_diagnostics/**/*.rs : Use #[derive(Diagnostic)] on enums when every variant contains a type that is itself a diagnostic

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Implement the `run` function to return `Option<Self::State>` or `Vec<Self::State>` (as `Box<[Self::State]>`) depending on whether the rule reports one or multiple signals

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule names should use the `use` prefix when the rule's sole intention is to mandate a single concept

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use the `Semantic<T>` query type to access semantic information about bindings, references, and scope within a rule

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-12-04T13:29:49.287Z

Learnt from: dyc3
Repo: biomejs/biome PR: 8291
File: crates/biome_html_formatter/tests/specs/prettier/vue/html-vue/elastic-header.html:10-10
Timestamp: 2025-12-04T13:29:49.287Z
Learning: Files under `crates/biome_html_formatter/tests/specs/prettier` are test fixtures synced from Prettier and should not receive detailed code quality reviews (e.g., HTTP vs HTTPS, formatting suggestions, etc.). These files are test data meant to validate formatter behavior and should be preserved as-is.

Applied to files:

• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts

🧬 Code graph analysis (1)

crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs (4)

crates/biome_service/src/workspace.rs (1)

• markup (1195-1197)

crates/biome_analyze/src/rule.rs (3)

• recommended (625-628)
• sources (640-643)
• same (255-260)

crates/biome_service/src/workspace_types.rs (1)

• Self (748-748)

crates/biome_js_analyze/src/lint/style/use_array_literals.rs (1)

• initializer (266-266)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (14)

• GitHub Check: Check JS Files
• GitHub Check: Documentation
• GitHub Check: Lint project (depot-windows-2022)
• GitHub Check: Test (depot-windows-2022-16)
• GitHub Check: autofix
• GitHub Check: Test (depot-ubuntu-24.04-arm-16)
• GitHub Check: Check Dependencies
• GitHub Check: Lint project (depot-ubuntu-24.04-arm-16)
• GitHub Check: End-to-end tests
• GitHub Check: Bench (biome_js_formatter)
• GitHub Check: Bench (biome_js_analyze)
• GitHub Check: Bench (biome_js_parser)
• GitHub Check: Test Node.js API
• GitHub Check: Bench (biome_configuration)

🔇 Additional comments (5)

crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts (1)

1-17: LGTM! Comprehensive test coverage.

The invalid test cases effectively cover numeric duplicates, string duplicates across different quote styles, and mixed implicit/explicit enum values.

crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts (1)

1-17: LGTM! Valid cases properly defined.

The valid test cases correctly demonstrate enums with unique member values, including explicit values, auto-increment, and different quote styles.

crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs (3)

13-67: Well-structured rule declaration.

The rule metadata and documentation follow all guidelines: version: "next", proper no prefix, nursery group placement, correct sources attribution, and comprehensive examples.

---

140-161: LGTM! Diagnostic implementation is correct.

The function properly creates a single diagnostic with the first duplicate as the primary location and additional duplicates as detail messages. The explanatory note clearly communicates the issue.

---

117-128: The test fixture confirms this works correctly. Enum Six with A = "A", B = 'A', and C = `A` correctly generates three duplicate diagnostics, meaning both inner_string_text() and to_trimmed_string() produce identical results for equivalent values.

[coderabbitai]

Actionable comments posted: 2

🤖 Fix all issues with AI agents

In @crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs:
- Around line 117-124: The early-return bug comes from using the `?` operator on
`elements.first()` — change that to an explicit conditional so a missing first
element only skips the current enum member instead of returning from the whole
function; replace `let first = elements.first()?;` with something like `if let
Some(first) = elements.first() { ... }` (keeping the existing `if let
AnyJsTemplateElement::JsTemplateChunkElement(chunk_element) = first &&
!found.insert(chunk_element.to_trimmed_string()) {
duplicates.push(member.range()); }` logic) so the loop continues to the next
member when `first` is None.

📜 Review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 8974ab7 and 66e339e.

📒 Files selected for processing (1)

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

🧰 Additional context used

📓 Path-based instructions (1)

**/*.rs

📄 CodeRabbit inference engine (CONTRIBUTING.md)

**/*.rs: Use inline rustdoc documentation for rules, assists, and their options
Use the dbg!() macro for debugging output in Rust tests and code
Use doc tests (doctest) format with code blocks in rustdoc comments; ensure assertions pass in tests

Files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

🧠 Learnings (22)

📓 Common learnings

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : New rules must be placed inside the `nursery` group before promotion to other groups

Learnt from: dyc3
Repo: biomejs/biome PR: 8639
File: crates/biome_js_analyze/src/lint/nursery/no_excessive_lines_per_file.rs:101-108
Timestamp: 2025-12-31T15:35:41.261Z
Learning: In crates/biome_analyze/**/*analyze/src/lint/nursery/**/*.rs, the `issue_number` field in `declare_lint_rule!` macro is optional and the vast majority of nursery rules do not need it. Do not recommend adding `issue_number` unless there's a specific reason.

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Invalid code snippets in rule documentation must emit exactly one diagnostic

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `declare_lint_rule!` macro with a `version` field set to `next` for new rules

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Invalid code snippets in rule documentation must emit exactly one diagnostic

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Deprecated rules must include a `deprecated` field in the `declare_lint_rule!` macro with an explanation of what rule to use instead

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : New rules must be placed inside the `nursery` group before promotion to other groups

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `declare_lint_rule!` macro with a `version` field set to `next` for new rules

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : When porting rules from other linters, use `sources` metadata with `RuleSource::Eslint().same()` for identical behavior or `.inspired()` for different behavior

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-12-31T15:35:32.899Z

Learnt from: dyc3
Repo: biomejs/biome PR: 8639
File: crates/biome_js_analyze/src/lint/nursery/no_excessive_lines_per_file.rs:101-108
Timestamp: 2025-12-31T15:35:32.899Z
Learning: In Rust lint rules under the nursery category, the issue_number field in declare_lint_rule! is optional and should not be added unless there is a compelling reason. In code reviews, verify that no unnecessary issue_number is included in nursery lint declarations. Only add issue_number if there is an explicit, justified reason (e.g., tracked issue for external observers). This guidance broadly applies to all nursery lint rule files, not just the single file.

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule names should use the `no` prefix when the rule's sole intention is to forbid a single concept

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-12-22T09:26:56.943Z

Learnt from: ematipico
Repo: biomejs/biome PR: 8537
File: crates/biome_js_analyze/src/lint/nursery/no_leaked_render.rs:167-210
Timestamp: 2025-12-22T09:26:56.943Z
Learning: When defining lint rules (declare_lint_rule!), only specify fix_kind if the rule implements an action(...) function. Rules that only emit diagnostics without a code fix should omit fix_kind. This applies to all Rust lint rule definitions under crates/.../src/lint (e.g., crates/biome_js_analyze/src/lint/...).

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Code blocks in rule documentation must specify a language identifier and be tagged with `expect_diagnostic` for invalid examples or remain untagged for valid examples

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule documentation must include an `## Examples` section followed by `### Invalid` and `### Valid` subsections, with Invalid appearing first

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use the `try operator (?)` to transform `Result` types into `Option` when the `run` function returns `Option`

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:05:27.810Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_js_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:05:27.810Z
Learning: Applies to crates/biome_js_formatter/**/*.rs : Do not attempt to 'fix' the code; if a token/node is known to be mandatory but is missing, return `None` instead

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use the `Semantic<T>` query type to access semantic information about bindings, references, and scope within a rule

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:06:03.545Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_parser/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:06:03.545Z
Learning: Applies to crates/biome_parser/**/src/**/*.rs : Use `p.eat(token)` for optional tokens, `p.expect(token)` for required tokens, `parse_rule(p).ok(p)` for optional nodes, and `parse_rule(p).or_add_diagnostic(p, error)` for required nodes

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : The first paragraph of rule documentation must be written in a single line to ensure proper rendering in the rules overview table

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Implement custom `Queryable` and `Visitor` types for rules that require deep inspection of child nodes to avoid inefficient traversals

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:06:03.545Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_parser/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:06:03.545Z
Learning: Applies to crates/biome_parser/**/src/**/*.rs : Use `ConditionalParsedSyntax` for syntax that is only valid in specific contexts (e.g., strict mode, file types, language versions) and call `or_invalid_to_bogus()` to convert to a bogus node if not supported

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:04:57.309Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_diagnostics/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:04:57.309Z
Learning: Applies to crates/biome_diagnostics/**/*.rs : Use #[derive(Diagnostic)] on enums when every variant contains a type that is itself a diagnostic

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Implement the `run` function to return `Option<Self::State>` or `Vec<Self::State>` (as `Box<[Self::State]>`) depending on whether the rule reports one or multiple signals

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule names should use the `use` prefix when the rule's sole intention is to mandate a single concept

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Apply `#[serde(deny_unknown_fields)]` to rule option structs to enforce strict configuration validation

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

🧬 Code graph analysis (1)

crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs (2)

crates/biome_service/src/workspace.rs (1)

• markup (1195-1197)

crates/biome_analyze/src/rule.rs (2)

• sources (640-643)
• same (255-260)

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[dyc3]

Does the source rule allow duplicates if they are marked with a @deprecated jsdoc comment? I can foresee users wanting that.

[Netail]

Does the source rule allow duplicates if they are marked with a @deprecated jsdoc comment? I can foresee users wanting that.

Doesn't seem like it. Do we support jsdocs already?

[ematipico]

Have you considered using this rule? https://biomejs.dev/linter/rules/use-unique-enum-value-names/

It does exactly the same.

[ematipico]

Does the source rule allow duplicates if they are marked with a @deprecated jsdoc comment? I can foresee users wanting that.

Doesn't seem like it. Do we support jsdocs already?

Yeah we do, but you'll need the project domain to pull that information

[Netail]

Have you considered using this rule? https://biomejs.dev/linter/rules/use-unique-enum-value-names/

It does exactly the same.

That's for GraphQL enums, which I would like to rename to use the prefix noDuplicate, opened a PR for that one.

[ematipico]

Ok they'll eventually have the same name, got it

[Netail]

Ok they'll eventually have the same name, got it

Should they be completely the same? One is about the names of the enums, the other the values of the enum. Hence noDuplicateEnumValues (this rule) & noDuplicateEnumValueNames (graphql rule). The enum names in Typescript are already checked by Typescript themself, so we don't have to port noDuplicateEnumValueNames to Typescript

[ematipico]

You're right! Apologies

[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In @crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs:
- Around line 75-138: The rule currently conflates numeric and string enum
initializers by storing everything in a HashSet<String> (the found variable in
run), causing false positives; change found to a HashSet<ValueKey> where
ValueKey is a small enum (e.g., ValueKey::Number(f64) and
ValueKey::String(String) or ValueKey::Template(String)) and compute/insert the
appropriate variant for JsNumberLiteralExpression (use the numeric value, not
to_string()), JsStringLiteralExpression (use inner string text) and
JsTemplateExpression chunk elements (use the trimmed string) so that numeric 0
and string "0" are treated as distinct keys before pushing duplicates into the
duplicates Vec.

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⛔ Files ignored due to path filters (8)

• crates/biome_cli/src/execute/migrate/eslint_any_rule_to_biome.rs is excluded by !**/migrate/eslint_any_rule_to_biome.rs and included by **
• crates/biome_configuration/src/analyzer/linter/rules.rs is excluded by !**/rules.rs and included by **
• crates/biome_diagnostics_categories/src/categories.rs is excluded by !**/categories.rs and included by **
• crates/biome_js_analyze/src/lint/nursery.rs is excluded by !**/nursery.rs and included by **
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts.snap is excluded by !**/*.snap and included by **
• packages/@biomejs/backend-jsonrpc/src/workspace.ts is excluded by !**/backend-jsonrpc/src/workspace.ts and included by **
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📒 Files selected for processing (6)

• .changeset/orange-news-sink.md
• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts
• crates/biome_rule_options/src/lib.rs
• crates/biome_rule_options/src/no_duplicate_enum_values.rs

🚧 Files skipped from review as they are similar to previous changes (4)

• .changeset/orange-news-sink.md
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts
• crates/biome_rule_options/src/no_duplicate_enum_values.rs
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts

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📓 Path-based instructions (1)

**/*.rs

📄 CodeRabbit inference engine (CONTRIBUTING.md)

**/*.rs: Use inline rustdoc documentation for rules, assists, and their options
Use the dbg!() macro for debugging output in Rust tests and code
Use doc tests (doctest) format with code blocks in rustdoc comments; ensure assertions pass in tests

Files:

• crates/biome_rule_options/src/lib.rs
• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

🧠 Learnings (33)

📓 Common learnings

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : New rules must be placed inside the `nursery` group before promotion to other groups

Learnt from: dyc3
Repo: biomejs/biome PR: 8639
File: crates/biome_js_analyze/src/lint/nursery/no_excessive_lines_per_file.rs:101-108
Timestamp: 2025-12-31T15:35:41.261Z
Learning: In crates/biome_analyze/**/*analyze/src/lint/nursery/**/*.rs, the `issue_number` field in `declare_lint_rule!` macro is optional and the vast majority of nursery rules do not need it. Do not recommend adding `issue_number` unless there's a specific reason.

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `declare_lint_rule!` macro with a `version` field set to `next` for new rules

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Rule options must be defined in the `biome_rule_options` crate with a file named after the rule

Applied to files:

• crates/biome_rule_options/src/lib.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Use `Option<_>` wrapper for rule option fields to enable proper merging of configurations

Applied to files:

• crates/biome_rule_options/src/lib.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Apply `#[serde(deny_unknown_fields)]` to rule option structs to enforce strict configuration validation

Applied to files:

• crates/biome_rule_options/src/lib.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Implement `biome_deserialize::Merge` for rule option types to define how shared and user configurations are merged

Applied to files:

• crates/biome_rule_options/src/lib.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Rule option types must derive `Deserializable`, `Serialize`, `Deserialize`, and optionally `JsonSchema` traits

Applied to files:

• crates/biome_rule_options/src/lib.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Apply `#[serde(rename_all = "camelCase")]` to rule option structs to match JSON configuration naming convention

Applied to files:

• crates/biome_rule_options/src/lib.rs

📚 Learning: 2025-11-24T18:05:42.356Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_js_type_info/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:05:42.356Z
Learning: Applies to crates/biome_js_type_info/**/*.rs : No module may copy or clone data from another module in the module graph, not even behind an `Arc`

Applied to files:

• crates/biome_rule_options/src/lib.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Use `Box<[Box<str>]>` instead of `Vec<String>` for collections of strings in rule options to save memory

Applied to files:

• crates/biome_rule_options/src/lib.rs

📚 Learning: 2025-11-24T18:04:57.309Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_diagnostics/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:04:57.309Z
Learning: Applies to crates/biome_diagnostics/**/*.rs : Use helper types from the biome_diagnostics::v2 module (CodeFrameAdvice, CommandAdvice, DiffAdvice, LogAdvice) or implement the Advices trait yourself for custom advice handling

Applied to files:

• crates/biome_rule_options/src/lib.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : New rules must be placed inside the `nursery` group before promotion to other groups

Applied to files:

• crates/biome_rule_options/src/lib.rs
• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Invalid code snippets in rule documentation must emit exactly one diagnostic

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Deprecated rules must include a `deprecated` field in the `declare_lint_rule!` macro with an explanation of what rule to use instead

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `declare_lint_rule!` macro with a `version` field set to `next` for new rules

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : When porting rules from other linters, use `sources` metadata with `RuleSource::Eslint().same()` for identical behavior or `.inspired()` for different behavior

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-12-22T09:26:56.943Z

Learnt from: ematipico
Repo: biomejs/biome PR: 8537
File: crates/biome_js_analyze/src/lint/nursery/no_leaked_render.rs:167-210
Timestamp: 2025-12-22T09:26:56.943Z
Learning: When defining lint rules (declare_lint_rule!), only specify fix_kind if the rule implements an action(...) function. Rules that only emit diagnostics without a code fix should omit fix_kind. This applies to all Rust lint rule definitions under crates/.../src/lint (e.g., crates/biome_js_analyze/src/lint/...).

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-12-31T15:35:32.899Z

Learnt from: dyc3
Repo: biomejs/biome PR: 8639
File: crates/biome_js_analyze/src/lint/nursery/no_excessive_lines_per_file.rs:101-108
Timestamp: 2025-12-31T15:35:32.899Z
Learning: In Rust lint rules under the nursery category, the issue_number field in declare_lint_rule! is optional and should not be added unless there is a compelling reason. In code reviews, verify that no unnecessary issue_number is included in nursery lint declarations. Only add issue_number if there is an explicit, justified reason (e.g., tracked issue for external observers). This guidance broadly applies to all nursery lint rule files, not just the single file.

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule names should use the `no` prefix when the rule's sole intention is to forbid a single concept

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Code blocks in rule documentation must specify a language identifier and be tagged with `expect_diagnostic` for invalid examples or remain untagged for valid examples

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `declare_node_union!` macro to query multiple node types together to avoid redundant traversal passes

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use the `try operator (?)` to transform `Result` types into `Option` when the `run` function returns `Option`

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:05:27.810Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_js_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:05:27.810Z
Learning: Applies to crates/biome_js_formatter/**/*.rs : Do not attempt to 'fix' the code; if a token/node is known to be mandatory but is missing, return `None` instead

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use the `Semantic<T>` query type to access semantic information about bindings, references, and scope within a rule

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:06:03.545Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_parser/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:06:03.545Z
Learning: Applies to crates/biome_parser/**/src/**/*.rs : Use `p.eat(token)` for optional tokens, `p.expect(token)` for required tokens, `parse_rule(p).ok(p)` for optional nodes, and `parse_rule(p).or_add_diagnostic(p, error)` for required nodes

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : The first paragraph of rule documentation must be written in a single line to ensure proper rendering in the rules overview table

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Implement custom `Queryable` and `Visitor` types for rules that require deep inspection of child nodes to avoid inefficient traversals

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule documentation must include an `## Examples` section followed by `### Invalid` and `### Valid` subsections, with Invalid appearing first

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:06:03.545Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_parser/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:06:03.545Z
Learning: Applies to crates/biome_parser/**/src/**/*.rs : Use `ConditionalParsedSyntax` for syntax that is only valid in specific contexts (e.g., strict mode, file types, language versions) and call `or_invalid_to_bogus()` to convert to a bogus node if not supported

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-21T01:10:53.059Z

Learnt from: dyc3
Repo: biomejs/biome PR: 8171
File: crates/biome_js_analyze/src/lint/nursery/no_leaked_render.rs:125-137
Timestamp: 2025-11-21T01:10:53.059Z
Learning: In the Biome codebase, each lint rule has its own options type declaration (e.g., `type Options = RuleNameOptions`) as part of the codegen process, even if the options struct is empty or unused. This is standard practice and should not be flagged as an issue.

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `.ok()?` to transform `Result` types into `Option` or `let else` pattern to handle errors when the function returns `Vec`

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:04:57.309Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_diagnostics/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:04:57.309Z
Learning: Applies to crates/biome_diagnostics/**/*.rs : Use #[derive(Diagnostic)] on enums when every variant contains a type that is itself a diagnostic

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Implement the `run` function to return `Option<Self::State>` or `Vec<Self::State>` (as `Box<[Self::State]>`) depending on whether the rule reports one or multiple signals

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule names should use the `use` prefix when the rule's sole intention is to mandate a single concept

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

🧬 Code graph analysis (1)

crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs (2)

crates/biome_service/src/workspace.rs (1)

• markup (1195-1197)

crates/biome_analyze/src/rule.rs (3)

• recommended (625-628)
• sources (640-643)
• same (255-260)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (15)

• GitHub Check: Test (depot-windows-2022-16)
• GitHub Check: Documentation
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• GitHub Check: Lint project (depot-windows-2022)
• GitHub Check: Test (depot-ubuntu-24.04-arm-16)
• GitHub Check: End-to-end tests
• GitHub Check: Lint project (depot-ubuntu-24.04-arm-16)
• GitHub Check: Validate rules documentation
• GitHub Check: Test Node.js API
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• GitHub Check: Check JS Files

🔇 Additional comments (4)

crates/biome_rule_options/src/lib.rs (1)

64-64: LGTM!

Module declaration is correctly placed and follows the established pattern.

crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs (3)

1-11: Imports look appropriate.

All necessary types are imported for the rule implementation.

---

13-67: Rule declaration follows conventions.

Metadata is correctly configured with version: "next", proper source attribution, and well-structured documentation with appropriate code block tags.

---

140-161: Diagnostic formatting is well structured.

The function correctly highlights the first duplicate and adds detail labels for subsequent occurrences, with a helpful explanatory note.

[coderabbitai]

Actionable comments posted: 0

🧹 Nitpick comments (1)

crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts (1)

7-12: Consider adding edge cases for numeric precision.

The test covers different representations of 1, which is excellent. You might also consider adding tests for:

• Negative numbers (-1 vs -1.0)
• Large integers near floating-point precision limits

Not blocking, just a thought for future hardening.

📜 Review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between eb5053b and 772973a.

⛔ Files ignored due to path filters (8)

• crates/biome_cli/src/execute/migrate/eslint_any_rule_to_biome.rs is excluded by !**/migrate/eslint_any_rule_to_biome.rs and included by **
• crates/biome_configuration/src/analyzer/linter/rules.rs is excluded by !**/rules.rs and included by **
• crates/biome_diagnostics_categories/src/categories.rs is excluded by !**/categories.rs and included by **
• crates/biome_js_analyze/src/lint/nursery.rs is excluded by !**/nursery.rs and included by **
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts.snap is excluded by !**/*.snap and included by **
• packages/@biomejs/backend-jsonrpc/src/workspace.ts is excluded by !**/backend-jsonrpc/src/workspace.ts and included by **
• packages/@biomejs/biome/configuration_schema.json is excluded by !**/configuration_schema.json and included by **

📒 Files selected for processing (6)

• .changeset/orange-news-sink.md
• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts
• crates/biome_rule_options/src/lib.rs
• crates/biome_rule_options/src/no_duplicate_enum_values.rs

🚧 Files skipped from review as they are similar to previous changes (3)

• crates/biome_rule_options/src/no_duplicate_enum_values.rs
• .changeset/orange-news-sink.md
• crates/biome_rule_options/src/lib.rs

🧰 Additional context used

📓 Path-based instructions (1)

**/*.rs

📄 CodeRabbit inference engine (CONTRIBUTING.md)

**/*.rs: Use inline rustdoc documentation for rules, assists, and their options
Use the dbg!() macro for debugging output in Rust tests and code
Use doc tests (doctest) format with code blocks in rustdoc comments; ensure assertions pass in tests

Files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

🧠 Learnings (25)

📓 Common learnings

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : New rules must be placed inside the `nursery` group before promotion to other groups

Learnt from: dyc3
Repo: biomejs/biome PR: 8639
File: crates/biome_js_analyze/src/lint/nursery/no_excessive_lines_per_file.rs:101-108
Timestamp: 2025-12-31T15:35:41.261Z
Learning: In crates/biome_analyze/**/*analyze/src/lint/nursery/**/*.rs, the `issue_number` field in `declare_lint_rule!` macro is optional and the vast majority of nursery rules do not need it. Do not recommend adding `issue_number` unless there's a specific reason.

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Invalid code snippets in rule documentation must emit exactly one diagnostic

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `declare_lint_rule!` macro with a `version` field set to `next` for new rules

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/biome_rule_options/lib/**/*.rs : Apply `#[serde(deny_unknown_fields)]` to rule option structs to enforce strict configuration validation

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Invalid code snippets in rule documentation must emit exactly one diagnostic

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : New rules must be placed inside the `nursery` group before promotion to other groups

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-12-31T15:35:32.899Z

Learnt from: dyc3
Repo: biomejs/biome PR: 8639
File: crates/biome_js_analyze/src/lint/nursery/no_excessive_lines_per_file.rs:101-108
Timestamp: 2025-12-31T15:35:32.899Z
Learning: In Rust lint rules under the nursery category, the issue_number field in declare_lint_rule! is optional and should not be added unless there is a compelling reason. In code reviews, verify that no unnecessary issue_number is included in nursery lint declarations. Only add issue_number if there is an explicit, justified reason (e.g., tracked issue for external observers). This guidance broadly applies to all nursery lint rule files, not just the single file.

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `declare_lint_rule!` macro with a `version` field set to `next` for new rules

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Deprecated rules must include a `deprecated` field in the `declare_lint_rule!` macro with an explanation of what rule to use instead

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : When porting rules from other linters, use `sources` metadata with `RuleSource::Eslint().same()` for identical behavior or `.inspired()` for different behavior

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-12-22T09:26:56.943Z

Learnt from: ematipico
Repo: biomejs/biome PR: 8537
File: crates/biome_js_analyze/src/lint/nursery/no_leaked_render.rs:167-210
Timestamp: 2025-12-22T09:26:56.943Z
Learning: When defining lint rules (declare_lint_rule!), only specify fix_kind if the rule implements an action(...) function. Rules that only emit diagnostics without a code fix should omit fix_kind. This applies to all Rust lint rule definitions under crates/.../src/lint (e.g., crates/biome_js_analyze/src/lint/...).

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule names should use the `no` prefix when the rule's sole intention is to forbid a single concept

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Mark rules with `issue_number` in the `declare_lint_rule!` macro if they are work-in-progress to indicate missing features

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use the `Semantic<T>` query type to access semantic information about bindings, references, and scope within a rule

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use the `try operator (?)` to transform `Result` types into `Option` when the `run` function returns `Option`

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:05:27.810Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_js_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:05:27.810Z
Learning: Applies to crates/biome_js_formatter/**/*.rs : Do not attempt to 'fix' the code; if a token/node is known to be mandatory but is missing, return `None` instead

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Code blocks in rule documentation must specify a language identifier and be tagged with `expect_diagnostic` for invalid examples or remain untagged for valid examples

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:06:03.545Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_parser/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:06:03.545Z
Learning: Applies to crates/biome_parser/**/src/**/*.rs : Use `p.eat(token)` for optional tokens, `p.expect(token)` for required tokens, `parse_rule(p).ok(p)` for optional nodes, and `parse_rule(p).or_add_diagnostic(p, error)` for required nodes

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : The first paragraph of rule documentation must be written in a single line to ensure proper rendering in the rules overview table

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Implement custom `Queryable` and `Visitor` types for rules that require deep inspection of child nodes to avoid inefficient traversals

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Rule documentation must include an `## Examples` section followed by `### Invalid` and `### Valid` subsections, with Invalid appearing first

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:06:03.545Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_parser/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:06:03.545Z
Learning: Applies to crates/biome_parser/**/src/**/*.rs : Use `ConditionalParsedSyntax` for syntax that is only valid in specific contexts (e.g., strict mode, file types, language versions) and call `or_invalid_to_bogus()` to convert to a bogus node if not supported

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-21T01:10:53.059Z

Learnt from: dyc3
Repo: biomejs/biome PR: 8171
File: crates/biome_js_analyze/src/lint/nursery/no_leaked_render.rs:125-137
Timestamp: 2025-11-21T01:10:53.059Z
Learning: In the Biome codebase, each lint rule has its own options type declaration (e.g., `type Options = RuleNameOptions`) as part of the codegen process, even if the options struct is empty or unused. This is standard practice and should not be flagged as an issue.

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Use `.ok()?` to transform `Result` types into `Option` or `let else` pattern to handle errors when the function returns `Vec`

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2025-11-24T18:04:57.309Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_diagnostics/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:04:57.309Z
Learning: Applies to crates/biome_diagnostics/**/*.rs : Use #[derive(Diagnostic)] on enums when every variant contains a type that is itself a diagnostic

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/*_analyze/**/src/lint/**/*.rs : Implement the `run` function to return `Option<Self::State>` or `Vec<Self::State>` (as `Box<[Self::State]>`) depending on whether the rule reports one or multiple signals

Applied to files:

• crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs

📚 Learning: 2026-01-02T14:58:16.536Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/tests/specs/**/* : Create test files with `invalid` and `valid` prefixes to represent code that should and should not trigger the rule

Applied to files:

• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts

📚 Learning: 2025-12-04T13:29:49.287Z

Learnt from: dyc3
Repo: biomejs/biome PR: 8291
File: crates/biome_html_formatter/tests/specs/prettier/vue/html-vue/elastic-header.html:10-10
Timestamp: 2025-12-04T13:29:49.287Z
Learning: Files under `crates/biome_html_formatter/tests/specs/prettier` are test fixtures synced from Prettier and should not receive detailed code quality reviews (e.g., HTTP vs HTTPS, formatting suggestions, etc.). These files are test data meant to validate formatter behavior and should be preserved as-is.

Applied to files:

• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts
• crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts

🧬 Code graph analysis (1)

crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs (1)

crates/biome_analyze/src/rule.rs (3)

• recommended (625-628)
• sources (640-643)
• same (255-260)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (14)

• GitHub Check: Test Node.js API
• GitHub Check: Lint project (depot-ubuntu-24.04-arm-16)
• GitHub Check: Bench (biome_configuration)
• GitHub Check: Test (depot-windows-2022-16)
• GitHub Check: Lint project (depot-windows-2022)
• GitHub Check: Test (depot-ubuntu-24.04-arm-16)
• GitHub Check: Documentation
• GitHub Check: Check Dependencies
• GitHub Check: End-to-end tests
• GitHub Check: Check JS Files
• GitHub Check: autofix
• GitHub Check: Bench (biome_js_analyze)
• GitHub Check: Bench (biome_js_formatter)
• GitHub Check: Bench (biome_js_parser)

🔇 Additional comments (8)

crates/biome_js_analyze/src/lint/nursery/no_duplicate_enum_values.rs (6)

1-11: LGTM!

Imports are appropriate and complete for the rule implementation.

---

13-67: LGTM!

Rule declaration follows project conventions correctly:

• version: "next" for new rules ✓
• sources uses .same() for identical behaviour to ESLint TypeScript ✓
• Documentation has single-line first paragraph ✓
• Examples section has Invalid before Valid ✓
• Each invalid example emits exactly one diagnostic ✓

Based on learnings, this follows the established patterns.

---

94-101: Number normalisation handles different literal representations correctly.

Using as_number() followed by to_string() ensures that 1, 1.0, 0x1, and 1e0 are all normalised to the same value for comparison. This matches the test case in invalid.ts.

---

140-161: Diagnostic structure is reasonable.

The diagnostic reports the first duplicate as the primary location with subsequent duplicates as details. One minor UX consideration: the diagnostic doesn't indicate which original member these are duplicates of, but this follows similar patterns in other linters and is acceptable.

---

164-168: LGTM!

Private enum for internal value tracking. Using String for both variants enables consistent hashing after normalisation.

---

114-128: Remove this comment – the concern is based on incorrect assumptions.

The code correctly handles both template chunks and string literals with consistent text extraction. text_trimmed() removes syntax trivia (comments and leading/trailing parser metadata), not string content. Both paths preserve the actual string value identically.

The existing test suite already validates this: Invalid3 confirms that "A", 'A', and `A` are all correctly flagged as duplicates.

Likely an incorrect or invalid review comment.

crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/valid.ts (1)

1-16: LGTM!

Good coverage of valid scenarios:

• Unique numeric values
• Unique string values across quote styles
• Mixed types (0 vs "0") correctly treated as distinct

Valid3 is particularly useful for verifying type-aware comparison.

crates/biome_js_analyze/tests/specs/nursery/noDuplicateEnumValues/invalid.ts (1)

1-18: LGTM!

Solid coverage of invalid scenarios:

• Basic duplicate detection
• Number normalisation across representations (1, 1.0, 0x1, 1e0)
• String equivalence across quote styles

Invalid2 is particularly valuable for verifying the normalisation logic.