Skip to content

feat(semantic): add "did you mean?" suggestions to undefined name errors#19102

Merged
graphite-app[bot] merged 1 commit intomainfrom
copilot/improve-undefined-export-errors
Feb 24, 2026
Merged

feat(semantic): add "did you mean?" suggestions to undefined name errors#19102
graphite-app[bot] merged 1 commit intomainfrom
copilot/improve-undefined-export-errors

Conversation

Copy link
Contributor

Copilot AI commented Feb 7, 2026

Improve undefined_export and related errors with name suggestions

This PR adds helpful "did you mean?" suggestions to errors where names are not found, using Levenshtein distance (threshold=2).

Example Output

undefined_export with suggestion:

Export 'myVarible' is not defined
help: Did you mean 'myVariable'?

private_field_undeclared with suggestion:

Private field '#privateFild' must be declared in an enclosing class
help: Did you mean '#privateField'?

invalid_label_target with suggestion:

Use of undefined label
help: Did you mean 'outerLoop'?

Implementation Details

  • Moved Levenshtein edit distance calculation from oxc_linter to oxc_span for reuse across crates
  • Uses a threshold of 2 for edit distance to suggest similar names
  • Collects available names from appropriate scopes only when errors are found (performance optimization)
Original prompt

Improve undefined_export and some other errors to include a hint that suggests similar names that are defined


💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

Copilot AI changed the title [WIP] Improve undefined export errors with suggested similar names Add "did you mean?" suggestions to undefined name errors Feb 7, 2026
Copilot AI requested a review from sapphi-red February 7, 2026 10:21
@github-actions github-actions bot added A-linter Area - Linter A-semantic Area - Semantic labels Feb 7, 2026
@codspeed-hq
Copy link

codspeed-hq bot commented Feb 7, 2026

Merging this PR will not alter performance

✅ 47 untouched benchmarks
⏩ 3 skipped benchmarks1


Comparing copilot/improve-undefined-export-errors (f14153d) with main (db7da3b)2

Open in CodSpeed

Footnotes

  1. 3 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.

  2. No successful run was found on main (a745e8e) during the generation of this report, so db7da3b was used instead as the comparison base. There might be some changes unrelated to this pull request in this report.

@sapphi-red
Copy link
Member

@copilot update conformance snapshot

Copy link
Contributor Author

Copilot AI commented Feb 7, 2026

@copilot update conformance snapshot

Updated in eccd1f3 - conformance snapshots now reflect the new "Did you mean?" suggestions in error messages for undefined exports, private fields, and labels.

@sapphi-red
Copy link
Member

@copilot fix lint and format

Copy link
Contributor Author

Copilot AI commented Feb 9, 2026

@copilot fix lint and format

Fixed in 3564b6b - addressed all clippy warnings (moved const declarations to function level, used method references instead of closures, used iterator references) and applied formatting.

@sapphi-red sapphi-red changed the title Add "did you mean?" suggestions to undefined name errors feat(semantic): add "did you mean?" suggestions to undefined name errors Feb 9, 2026
@github-actions github-actions bot added the C-enhancement Category - New feature or request label Feb 9, 2026
@sapphi-red sapphi-red marked this pull request as ready for review February 9, 2026 11:16
Copilot AI review requested due to automatic review settings February 9, 2026 11:16
@sapphi-red sapphi-red requested a review from Boshen February 9, 2026 11:16
Copy link
Contributor

Copilot AI left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Pull request overview

This PR improves semantic/early-error diagnostics by adding “Did you mean …?” suggestions when a referenced name isn’t found, and centralizes Levenshtein edit-distance utilities for reuse across crates.

Changes:

  • Add best_match / min_edit_distance utilities to oxc_span and remove the linter-local copy.
  • Enhance semantic diagnostics for undefined_export, private_field_undeclared, and invalid_label_target to optionally include a suggestion.
  • Update coverage snapshots to reflect the new help: output lines.

Reviewed changes

Copilot reviewed 7 out of 10 changed files in this pull request and generated 3 comments.

Show a summary per file
File Description
tasks/coverage/snapshots/parser_typescript.snap Updates expected TS diagnostic snapshots to include new help: Did you mean ...? lines.
tasks/coverage/snapshots/parser_test262.snap Updates expected Test262 diagnostic snapshots to include new suggestion help lines where applicable.
tasks/coverage/snapshots/parser_babel.snap Updates expected Babel fixture snapshots to include export-name suggestion help.
crates/oxc_span/src/lib.rs Adds the new edit_distance module and re-exports best_match/min_edit_distance.
crates/oxc_span/src/edit_distance.rs Provides the shared Levenshtein implementation and adds unit tests.
crates/oxc_semantic/src/diagnostics.rs Extends select diagnostics to accept an optional suggestion and emit .with_help(...).
crates/oxc_semantic/src/checker/javascript.rs Computes in-scope candidate names/labels on-demand and wires suggestions into diagnostics.
crates/oxc_linter/src/utils/mod.rs Removes the linter-local edit_distance module export.
crates/oxc_linter/src/rules/nextjs/no_typos.rs Switches to importing best_match from oxc_span.
crates/oxc_linter/src/rules/eslint/valid_typeof.rs Switches to importing best_match from oxc_span.

@Boshen Boshen added the 0-merge Merge with Graphite Merge Queue label Feb 24, 2026
Copy link
Member

Boshen commented Feb 24, 2026

Merge activity

…ors (#19102)

## Improve `undefined_export` and related errors with name suggestions

This PR adds helpful "did you mean?" suggestions to errors where names are not found, using Levenshtein distance (threshold=2).

### Example Output

**undefined_export with suggestion:**
```
Export 'myVarible' is not defined
help: Did you mean 'myVariable'?
```

**private_field_undeclared with suggestion:**
```
Private field '#privateFild' must be declared in an enclosing class
help: Did you mean '#privateField'?
```

**invalid_label_target with suggestion:**
```
Use of undefined label
help: Did you mean 'outerLoop'?
```

### Implementation Details

- Moved Levenshtein edit distance calculation from `oxc_linter` to `oxc_span` for reuse across crates
- Uses a threshold of 2 for edit distance to suggest similar names
- Collects available names from appropriate scopes only when errors are found (performance optimization)

<!-- START COPILOT CODING AGENT SUFFIX -->

<!-- START COPILOT ORIGINAL PROMPT -->

<details>

<summary>Original prompt</summary>

> Improve `undefined_export` and some other errors to include a hint that suggests similar names that are defined

</details>

<!-- START COPILOT CODING AGENT TIPS -->
---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more [Copilot coding agent tips](https://gh.io/copilot-coding-agent-tips) in the docs.
@graphite-app graphite-app bot force-pushed the copilot/improve-undefined-export-errors branch from f14153d to 655c38f Compare February 24, 2026 06:27
@graphite-app graphite-app bot merged commit 655c38f into main Feb 24, 2026
21 checks passed
@graphite-app graphite-app bot removed the 0-merge Merge with Graphite Merge Queue label Feb 24, 2026
@graphite-app graphite-app bot deleted the copilot/improve-undefined-export-errors branch February 24, 2026 06:34
camc314 pushed a commit that referenced this pull request Mar 2, 2026
### 🚀 Features

- 733d6dc parser: Report error on `infer` outside conditional type
(#19879) (camc314)
- c2a42f6 allocator: Add `Vec::into_bump_slice_mut` (#19895)
(overlookmotel)
- ee4982b parser: Add `VARIANTS` const to `Kind` via `fieldless_enum!`
macro (#19877) (overlookmotel)
- b3dceae data_structures: Add `fieldless_enum!` macro (#19876)
(overlookmotel)
- 12b841e parser: Make all `Kind::is_*` methods `const` (#19874)
(overlookmotel)
- 25c2e25 estree/tokens: Add function to update tokens in place (#19856)
(overlookmotel)
- f78e6df parser: Add `mutate_tokens` Cargo feature (#19853)
(overlookmotel)
- 5036bb6 parser: Report error on `for await` in static blocks (#19844)
(camc314)
- 42bd431 parser: Report error for missing initializer in using decl
(#19824) (camc314)
- a2f58e5 parser: Report error for `implements` clause in non-ts files
(#19820) (Cameron)
- b25228a estree: Add `IS_COMPACT` const to `Formatter` trait (#19787)
(overlookmotel)
- e2a1b79 estree: Expose buffer and formatter of serializers (#19773)
(overlookmotel)
- 4699498 data_structures: Add `CodeBuffer::print_strs_array` (#19760)
(overlookmotel)
- 233f947 estree: `oxc_estree` crate export config and formatter types
(#19724) (overlookmotel)
- 5937a32 semantic: Introduce `symbol_declarations` method (#19609)
(camc314)
- ea6b796 parser: Add `LexerConfig::TOKENS_METHOD_IS_STATIC` const
(#19683) (overlookmotel)
- 655c38f semantic: Add "did you mean?" suggestions to undefined name
errors (#19102) (copilot-swe-agent)
- 9e11dc6 parser,estree,coverage: Collect tokens in parser and convert
to ESTree format (#19497) (camc314)
- c4a3677 parser: Report error for initializer in ambient context
(#19187) (camc314)

### 🐛 Bug Fixes

- abc7e19 codegen: Improve parenthesised checks when printing types
(#19880) (camc314)
- 017de5d parser: Update error code for type annotation in `for...in`
statement (#19882) (camc314)
- 7682e5a linter/plugins: Decode escapes in identifier tokens (#19838)
(overlookmotel)
- 06767ed estree/tokens: Convert `this` tokens in `TSTypeName` (#19815)
(overlookmotel)
- ef798af parser: Use TS8037 for satisfies expression in JS files
diagnostic (#19819) (camc314)
- 98ea5c5 parser: Use TS8016 for type assertions in JS files diagnostic
(#19818) (camc314)
- 1710f56 codegen: Remove double indentation for enum inside namespace
(#19775) (Dunqing)
- 9e4995c codegen: Print type annotation on `CatchParameter` (#19790)
(camc314)
- 297b2bb codegen: Wrap `TSConditionalType` in parens when necessary
(#19788) (camc314)
- cec7878 codegen: Print `definite` property on AccessorProperty
(#19786) (camc314)
- 6f395cf codegen: Print `definite` property on PropertyDefinition
(#19785) (camc314)
- b749373 codegen: Correctly parenthesise TSArrayType (#19784) (camc314)
- 876dc1b codegen: Print object property `this` param (#19783) (camc314)
- 93bb861 formatter: Trim trailing whitespace before breaking line
(#19740) (leaysgur)
- ed17bbf codegen: Print `override` keyword for method and property
definitions (#19753) (Dunqing)
- 6a59a76 parser: Improve error recovery for private identifiers in
property names (#19710) (Boshen)
- 3b96f41 codegen: Print comments in JSX expression containers and
spread attributes (#19701) (Boshen)
- f5694ce estree/tokens: Reverse field order of `regex` object in tokens
(#19679) (overlookmotel)
- b2b7a55 estree/tokens: Generate tokens for files with BOM (#19535)
(overlookmotel)
- 50a7514 estree: Fix tokens for JSX (#19524) (overlookmotel)
- a35063e minifier: Preserve side effects for meta property url reads
(#19668) (Boshen)
- 8ad3430 semantic/jsdoc: Handle even-numbered backtick sequences in
JSDoc parsing (#19664) (Boshen)

### ⚡ Performance

- 05ccf9f linter/plugins: Transfer tokens via raw transfer (#19893)
(overlookmotel)
- c1bfdcf estree/tokens: Preallocate sufficient space for tokens JSON
(#19851) (overlookmotel)
- 4b0611a estree/tokens: Introduce `ESTreeTokenConfig` trait (#19842)
(overlookmotel)
- 81bab90 estree/tokens: Do not JSON-encode keyword, punctuator, etc
tokens (#19814) (overlookmotel)
- 6260ddd estree/tokens: Do not JSON-encode `this` identifiers (#19813)
(overlookmotel)
- b378f4a estree/tokens: Do not JSON-encode JSX identifiers (#19812)
(overlookmotel)
- 5016d92 estree/tokens: Handle regex tokens separately (#19796)
(overlookmotel)
- 780a68e estree/tokens: Use strings from AST for identifier tokens
(#19744) (overlookmotel)
- dc9c2e3 estree: Use `CodeBuffer::print_strs_array` to reduce bounds
checks (#19766) (overlookmotel)
- 845da35 estree: Use `CodeBuffer::print_indent` (#19727)
(overlookmotel)
- ec88f6a estree/tokens: Serialize tokens while visiting AST (#19726)
(overlookmotel)
- bc6507f estree/tokens: Serialize with `ESTree` not `serde` (#19725)
(overlookmotel)
- ec24859 estree/tokens: Do not branch on presence of override twice
(#19721) (overlookmotel)
- dac14be estree/tokens: Replace hash map with `Vec` (#19718)
(overlookmotel)
- b9d2443 estree/tokens: Replace multiple hash sets into a single hash
map (#19716) (overlookmotel)
- 7233548 parser: Remove branches from `finish_next_inner` (#19695)
(overlookmotel)
- b5d9845 parser: Remove const generic param from `finish_next_inner`
(#19684) (overlookmotel)
- 8940f66 estree/tokens: Serialize tokens to compact JSON (#19572)
(overlookmotel)
- 136e39b parser/tokens: Pre-allocate capacity for tokens (#19543)
(overlookmotel)
- 6a6513c linter/plugins: Use Oxc tokens in plugins (#19498) (camc314)
- b3b2d30 parser: Introduce `ParserConfig` (#19637) (overlookmotel)

### 📚 Documentation

- b2b7a64 estree/tokens: Correct comment (#19873) (overlookmotel)
- 0399311 estree/tokens: Improve comments (#19836) (overlookmotel)
- 1b392de minifier: Add `Function.prototype.toString` assumption
(#19758) (sapphi-red)
- 75c9cd8 parser: Improve doc comments for `ParserConfig` and
`LexerConfig` (#19682) (overlookmotel)
- 2fa936f README.md: Map npm package links to npmx.dev (#19666) (Boshen)

Co-authored-by: Boshen <1430279+Boshen@users.noreply.github.com>
camc314 pushed a commit that referenced this pull request Mar 2, 2026
# Oxlint
### 🚀 Features

- 2e0e1d0 linter/no-unused-vars: Add experimental fix mode controls
(off|suggestion|fix) (#19774) (camc314)
- f34f6fa linter: Introduce typeCheck config option (#19764) (camc314)
- 694be7d linter: Introduce typeAware as config options (#19614)
(camc314)
- 655c38f semantic: Add "did you mean?" suggestions to undefined name
errors (#19102) (copilot-swe-agent)
- e97a57e linter/id-length: Use serde to deserialize rule options
(#19636) (camc314)
- c4a3677 parser: Report error for initializer in ambient context
(#19187) (camc314)
- 346045a linter/id-length: Add `checkGeneric` option (#19634) (camc314)

### 🐛 Bug Fixes

- 1b7a937 linter: Correct double-comparisons fix with swapped operands
(#19846) (camc314)
- c308857 linter/consistent_type_imports: Add missing help and notes to
diagnostics (#19827) (Daniel Osmond)
- 7682e5a linter/plugins: Decode escapes in identifier tokens (#19838)
(overlookmotel)
- f368fcd linter/consistent_type_assertions: Add missing with_help and
with_note to diagnostics (#19826) (Daniel Osmond)
- 04e6223 npm: Add `preferUnplugged` for Yarn PnP compatibility (#19829)
(Boshen)
- 86d5037 linter: Add help text to no-extend-native,
no-useless-backreference (#19733) (Anthony Amaro)
- 50e8eff linter: Add .with_help() to operator-assignment,
no-nonoctal-decimal-escape (#19732) (Anthony Amaro)
- 1417bdc linter/no-wrapper-object-types: Add help messages to missing
diagnostics (#19771) (Daniel Osmond)
- 0838477 linter/ban_ts_comment: Add help and notes to missing
diagnostics (#19781) (Daniel Osmond)
- e8c77cf linter/adjacent_overload_signatures: Add missing diagnostics
(#19780) (Daniel Osmond)
- 28834ac linter/ban_types: Add missing help and note to diagnostics
(#19782) (Daniel Osmond)
- fd938d3 linter/prefer-enum-initializers: Add help messages to missing
diagnostics (#19772) (Daniel Osmond)
- eb928ee linter/no-dynamic-delete: Add help messages to missing
diagnostics (#19768) (Daniel Osmond)
- a985666 linter/no-empty-interface: Add help messages to missing
diagnostics (#19769) (Daniel Osmond)
- 2dc0ceb linter/no-extra-non-null-assertion: Add help messages to
missing diagnostics (#19770) (Daniel Osmond)
- 95d5d66 linter/no-dupe-keys: Handle `__proto__` proto setters in
(#19762) (camc314)
- 24ff0db linter/exhaustive-deps: False positive for member expressions
in IIFEs (#19751) (Dennis Chen)
- 7243a58 linter/no-use-before-define: Honor `ignoreTypeReferences` when
value and type name collisions (#19747) (Dimava)
- eefd818 linter/explicit-module-boundary-types: Add help messages to
missing diagnostics (#19736) (Daniel Osmond)
- 0440e9a linter: Add help text to no_control_regex, no_fallthrough,
no_param_reassign (#19655) (Anthony Amaro)
- e84cb2f react/display-name: Handle merged type+value context symbols
(#19608) (camc314)
- ce7e253 linter/prefer-object-from-entries: Require exact path match in
unicorn helper (#19687) (camc314)
- f5694ce estree/tokens: Reverse field order of `regex` object in tokens
(#19679) (overlookmotel)
- b2b7a55 estree/tokens: Generate tokens for files with BOM (#19535)
(overlookmotel)
- 0722721 linter/jsx-curly-brace-presence: False positive with prop &
mixed quotes (#19674) (camc314)
- 3496acd linter: Enhance diagnostic help messages for eslint rules
(#19653) (Anthony Amaro)
- e384e94 linter: Enhance help diagnostic messages for more eslint rules
(#19658) (Anthony Amaro)
- a4d5b34 linter: Avoid non-promise catch false positives (#19574)
(camc314)
- 5706f38 linter: `unicorn/no-array-callback-reference` skip `Effect.*`
array-like methods name. (#19633) (Said Atrahouch)

### ⚡ Performance

- 05ccf9f linter/plugins: Transfer tokens via raw transfer (#19893)
(overlookmotel)
- 4b0611a estree/tokens: Introduce `ESTreeTokenConfig` trait (#19842)
(overlookmotel)
- ec88f6a estree/tokens: Serialize tokens while visiting AST (#19726)
(overlookmotel)
- d4dcf26 linter/plugins: Remove `typescript` from bundle (#19531)
(overlookmotel)
- 6a6513c linter/plugins: Use Oxc tokens in plugins (#19498) (camc314)

### 📚 Documentation

- d86f59e linter: Improve docs for no-useless-concat, mark as pending
fixer. (#19859) (connorshea)
- caa091d linter/plugins: Correct doc comments for `initTokens` (#19530)
(overlookmotel)
- 2fa936f README.md: Map npm package links to npmx.dev (#19666) (Boshen)
- dc0ff73 linter/no-useless-constructor: Warn for parameter properties
as well (#19638) (Ole Asteo)
# Oxfmt
### 🚀 Features

- 5141bc2 formatter: Support trailing ignore comments (#19304) (Andreas
Lubbe)
- 4888a99 oxfmt/lsp: Support other schemes beside `file://` and
`untitled://` (#19872) (Sysix)
- 14a0181 oxfmt: Support `graphql()` variant for gql-in-js (#19703)
(leaysgur)
- ca68ea6 oxfmt: Support gql-in-js substitution (#19670) (leaysgur)
- 035933c formatter,oxfmt: Support js-in-vue (partially) (#19514)
(leaysgur)
- 9e11dc6 parser,estree,coverage: Collect tokens in parser and convert
to ESTree format (#19497) (camc314)

### 🐛 Bug Fixes

- 8e3842d oxfmt: Avoid embedded TSFN crash by returning errors as data
(take2) (#19806) (Yuji Sugiura)
- 04e6223 npm: Add `preferUnplugged` for Yarn PnP compatibility (#19829)
(Boshen)
- e540585 oxfmt: Support tailwind sort for CSS/LESS/SCSS (#19803)
(leaysgur)
- 93bb861 formatter: Trim trailing whitespace before breaking line
(#19740) (leaysgur)
- b85f97b formatter: Drop blank line between terminal call and first
chain member (#19659) (Dunqing)

### ⚡ Performance

- b3b2d30 parser: Introduce `ParserConfig` (#19637) (overlookmotel)

### 📚 Documentation

- 2fa936f README.md: Map npm package links to npmx.dev (#19666) (Boshen)

Co-authored-by: Boshen <1430279+Boshen@users.noreply.github.com>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

A-linter Area - Linter A-semantic Area - Semantic C-enhancement Category - New feature or request

Projects

None yet

Development

Successfully merging this pull request may close these issues.

5 participants