feat(lint/js): add useStringStartsEndsWith

[dyc3]

Summary

This adds useStringStartsEndsWith, which is a port of https://typescript-eslint.io/rules/prefer-string-starts-ends-with/

I chose to use type info (like the source rule) because my hunch is that there would be way too many false positives otherwise. Also, I chose to split the invalid tests into a bunch of files because the rule is very complex, and it makes it easier to spot whether diagnostics are getting emitted.

generated by gpt 5.4, but heavily guided to stop it from doing dumb things.

closes #7653
supersedes and closes #8582

Test Plan

all the tests are from the source rule, excluding the ones depending on the source rule's option

Docs

[changeset-bot]

🦋 Changeset detected

Latest commit: 0abca04

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

Not sure what this means? Click here to learn what changesets are.

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

[codspeed-hq]

Merging this PR will not alter performance

✅ 58 untouched benchmarks
⏩ 196 skipped benchmarks¹

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_{Comparing dyc3/useStringStartsEndsWith (0abca04) with main (1d09f0f)}

Footnotes

1. 196 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]

Walkthrough

A new linter rule useStringStartsEndsWith was added to the Biome JS/TS analyser. It detects string prefix/suffix checks expressed via binary comparisons and string/regex methods (e.g. indexOf, charAt, match, slice, substring, anchored RegExp.test) and emits diagnostics with optional automatic fixes rewriting to startsWith()/endsWith(). Changes include the rule implementation, a RuleState type and fix plan logic, an empty options struct and module export, and comprehensive valid/invalid test fixtures.

Suggested reviewers

• ematipico
• Netail

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'feat(lint/js): add useStringStartsEndsWith' clearly summarises the main change: adding a new JavaScript linter rule.
Description check	✅ Passed	The description explains the motivation (porting typescript-eslint rule), implementation choices (type info to avoid false positives), test structure, and references linked issues.
Linked Issues check	✅ Passed	The PR implements all coding requirements from #7653 and #8582: it ports the prefer-string-starts-ends-with rule to Biome with type-aware detection and comprehensive test coverage matching the source rule.
Out of Scope Changes check	✅ Passed	All changes are scoped to implementing the new rule: rule definition, test fixtures, rule options, and module registration. No extraneous modifications detected.

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

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch dyc3/useStringStartsEndsWith

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[coderabbitai]

🧹 Nitpick comments (1)

.changeset/rude-apples-prove.md (1)

5-7: Changeset description is clear and user-focused.

The description accurately conveys the rule's purpose and its type-aware behaviour. A minor clarity improvement: consider adding a comma after "strings" to make the compound structure clearer.

📝 Optional clarity tweak

-The rule uses type information, so it only reports on strings and skips array lookups such as `items[0] === "a"`.
+The rule uses type information, so it only reports on strings, and skips array lookups such as `items[0] === "a"`.

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In @.changeset/rude-apples-prove.md around lines 5 - 7, The changeset sentence
describing the rule's type-aware behavior needs a comma for clarity: update the
sentence that mentions the rule "uses type information" so that the clause reads
"so it only reports on strings, and skips array lookups such as `items[0] ===
\"a\"`" — modify the text referring to useStringStartsEndsWith to insert the
comma after "strings" to improve readability.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In @.changeset/rude-apples-prove.md:
- Around line 5-7: The changeset sentence describing the rule's type-aware
behavior needs a comma for clarity: update the sentence that mentions the rule
"uses type information" so that the clause reads "so it only reports on strings,
and skips array lookups such as `items[0] === \"a\"`" — modify the text
referring to useStringStartsEndsWith to insert the comma after "strings" to
improve readability.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 16cea3ab-836c-48e7-b2c0-84534420d57f

📥 Commits

Reviewing files that changed from the base of the PR and between 328c0e5 and 0abca04.

⛔ Files ignored due to path filters (14)

• 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_configuration/src/generated/domain_selector.rs is excluded by !**/generated/**, !**/generated/** and included by **
• crates/biome_configuration/src/generated/linter_options_check.rs is excluded by !**/generated/**, !**/generated/** and included by **
• crates/biome_diagnostics_categories/src/categories.rs is excluded by !**/categories.rs and included by **
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidCharAt.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidIndex.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidNoFix.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidRegex.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidSearch.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidSlice.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/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 (11)

• .changeset/rude-apples-prove.md
• crates/biome_js_analyze/src/lint/nursery/use_string_starts_ends_with.rs
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidCharAt.ts
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidIndex.ts
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidNoFix.ts
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidRegex.ts
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidSearch.ts
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidSlice.ts
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/valid.ts
• crates/biome_rule_options/src/lib.rs
• crates/biome_rule_options/src/use_string_starts_ends_with.rs

✅ Files skipped from review due to trivial changes (9)

• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidSlice.ts
• crates/biome_rule_options/src/lib.rs
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidSearch.ts
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidRegex.ts
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidNoFix.ts
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidIndex.ts
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/invalidCharAt.ts
• crates/biome_js_analyze/tests/specs/nursery/useStringStartsEndsWith/valid.ts
• crates/biome_rule_options/src/use_string_starts_ends_with.rs