fix(linter/plugins): fix type definition for `VisitorObject` by overlookmotel · Pull Request #20065 · oxc-project/oxc

overlookmotel · 2026-03-06T09:30:13Z

Use the bivariance hack to fix the type def for VisitorObject. The bivariance hack is taken from DefinitelyTyped/DefinitelyTyped#20219.

This was originally written by @sapphi-red in #19675. I've split it out into a separate PR. I can't claim to understand this witchcraft!

overlookmotel · 2026-03-06T09:30:27Z

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Copilot

Pull request overview

Updates Oxlint’s generated JS plugin type definitions so custom rule visitors (returned from create/createOnce) can use narrower node parameter types without TypeScript rejecting them (per issues #18154 and #14745), by applying the “bivariance hack” to visitor handler function types.

Changes:

Adjusts the visitor type generator to emit a VisitorObject type that applies a bivariance wrapper to handler function types.
Regenerates apps/oxlint/src-js/generated/visitor.d.ts to match the new output.

Reviewed changes

Copilot reviewed 1 out of 2 changed files in this pull request and generated 1 comment.

File	Description
tasks/ast_tools/src/generators/estree_visit.rs	Changes the generator output for Oxlint’s `VisitorObject` to use a bivariance wrapper and a strict visitor shape.
apps/oxlint/src-js/generated/visitor.d.ts	Regenerated output reflecting the new `VisitorObject` typing approach.

tasks/ast_tools/src/generators/estree_visit.rs

Copilot

Pull request overview

Copilot reviewed 1 out of 2 changed files in this pull request and generated no new comments.

camc314 · 2026-03-06T15:59:22Z

Merge activity

Mar 6, 3:59 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
Mar 6, 3:59 PM UTC: camc314 added this pull request to the Graphite merge queue.
Mar 6, 4:07 PM UTC: Merged by the Graphite merge queue.

@sapphi-red

Fixes #18154, #14745. Use the bivariance hack to fix the type def for `VisitorObject`. The bivariance hack is taken from DefinitelyTyped/DefinitelyTyped#20219. This was originally written by @sapphi-red in #19675. I've split it out into a separate PR. I can't claim to understand this witchcraft!

Add a types test for #20065. This is a separate PR as it depends on `strict: true` TS config option added in #19675.

…ated code (#20082) Follow-on after #20065. That PR added a comment about the "bivariance hack", but that comment was in the `ast_tools` codegen. Move the comment into the generated code, as that's what people will be looking at when they ask themselves "what the hell is this thing?". Also add a link to [my comment](#18154 (comment)) about the shortcomings of the hack approach.

# Oxlint ### 🚀 Features - e6b604f oxlint: Auto-enable gitlab formatter on GitLab (#20076) (camc314) - 2488a68 linter: Add .oxlintrc.jsonc config file support (#19870) (Scott S.) - 61bf388 linter: Add `options.reportUnusedDisableDirectives` to config file (#19799) (Peter Wagenet) - c92422b oxlint: Auto-enable github formatter on GitHub Actions (#19944) (Boshen) - 0337c6d linter: Implement typescript/no-unecessary-type-conversion (#19955) (camc314) - 2919313 linter: Introduce denyWarnings config options (#19926) (camc314) - a607119 linter: Introduce maxWarnings config option (#19777) (camc314) ### 🐛 Bug Fixes - 0861d9a linter/plugins: Remove getters from `Context` (#20115) (overlookmotel) - 92cfb14 linter/plugins: Fix types for `walkProgram` and `walkProgramWithCfg` (#20081) (overlookmotel) - 10e211f oxlint/lsp: Send other code actions besides `source.fixAll` if requested (#20042) (Sysix) - 602daaa linter/plugins: Fix type definition for `VisitorObject` (#20065) (overlookmotel) - ee0491e apps,napi: Explicitly specify libs in tsconfigs (#20071) (camc314) - b6e9499 linter: Fix the logic for `unicorn/prefer-dom-node-remove` to handle literal callees as well as arguments. (#20059) (connorshea) - 3874ae1 linter: Update `unicorn/prefer-query-selector` to also catch `getElementsByName()`. (#20060) (connorshea) - 77c93fb linter: Handle array-type shorthand inside union members (#20034) (camc314) - 50eb160 linter/no-unused-vars: Allow unused type params in ambient module blocks (#19615) (Don Isaac) - 1dd0d21 linter/no-restricted-imports: Apply regex pattern checks to side-effect imports (#20028) (camc314) - 7f3d735 linter: Error when --type-check is used without --type-aware (#20025) (camc314) - eea201c unicorn/prefer-string-slice: Avoid unsafe autofix for substr-to-slice (#20010) (camc314) - 50359dc oxlint/lsp: Detect `reportUnusedDisableDirectives` from oxlint config, change lsp `unusedDisableDirectives` default value to `None` (#20011) (Sysix) - 4bc84b1 linter/plugins: Allow `null` and `undefined` for `rule.meta.fixable` (#20008) (overlookmotel) - 753e27e linter/role-supports-aria-props: Add `aria-posinset` to supported `option` ARIA properties (#20003) (JongKyung Lee) - f57b2c9 linter/plugins: Fix return types of tokens methods (#19985) (overlookmotel) - 27ee4fc linter/no-loss-of-precision: Avoid double rounding for negative exponents (#19999) (camc314) - 77a94bb linter: Avoid no-loss-of-precision false positive for 3e-308 (#19992) (camc314) - 6245c56 linter/no-unused-private-class-members: Treat logical lhs access as usage (#19991) (camc314) - 65891e3 linter: Avoid prefer-const false positive for mixed-scope destructuring (#19982) (camc314) - 89991fe linter: Avoid prefer-const false positive for operator reassignments (#19975) (camc314) - 87318e7 oxlint/lsp: Load js config with reforcing fs read (#19551) (Sysix) - d40a942 linter/no-useless-constructor: Mark fixer as suggestion (#19961) (camc314) - ccbd959 linter/prefer-code-point: Report String.fromCharCode member references (#19931) (camc314) - 14fbbfc linter: Add help text to oxc/no-rest-spread-properties rule (#19900) (Subin Kim) ### ⚡ Performance - 2baa5fb napi: Unify build-test profile to coverage for cache sharing (#20090) (Boshen) - 77f1c71 linter/plugins: Make tokens class instances (#19980) (overlookmotel) - 758b424 linter/plugins: Reduce memory copies for tokens (#19979) (overlookmotel) - 236847f linter/plugins: Cache token objects (#19978) (overlookmotel) - 94b597a linter/plugins: Store tokens as a `Box<[Token]>` (#19969) (overlookmotel) ### 📚 Documentation - 2c0010a linter/plugins: Move comment about "bivariance hack" into generated code (#20082) (overlookmotel) - 7538f09 linter: Improve `import/extensions` and `import/no-named-as-default` rule docs. (#20053) (connorshea) - 1f909cf linter: Improve docs for `unicorn/require-post-message-target-origin` rule. (#20061) (connorshea) - 12ae35c oxlint/lsp: Remove outdated ToDo for `LintOptions.run` (#20012) (Sysix) - 3be73e6 linter/plugins: Fix JSDoc comments for tokens methods (#20004) (overlookmotel) - 48ef285 linter: Update `--config` docs (#19965) (camc314) - 6ea49a0 linter: Fix some identation issues for the generated types used in `oxlint.config.ts`. (#19942) (connorshea) - 6c0e0b5 linter: Add oxlint.config.ts to the config docs. (#19941) (connorshea) - 160e423 linter: Add a note that the typeAware and typeCheck options require oxlint-tsgolint (#19940) (connorshea) - d54c275 linter: Improve rule docs for 27 unicorn rules (#19903) (connorshea) # Oxfmt ### 🚀 Features - ee26215 oxfmt: Support css-in-js substitution (#20019) (leaysgur) - 0f0ff51 oxfmt: Display default settings was used message in cli stats (#19939) (leaysgur) - 88815b8 oxfmt: Reintroduce stats line for write mode (#19938) (leaysgur) ### 🐛 Bug Fixes - ee0491e apps,napi: Explicitly specify libs in tsconfigs (#20071) (camc314) - 92f4490 oxfmt: Apply `is_ignored_dir` for glob paths too (#20056) (leaysgur) - 114f974 oxfmt/lsp: Prefer language_id over file extension when formatting (#19977) (copilot-swe-agent) ### ⚡ Performance - 2baa5fb napi: Unify build-test profile to coverage for cache sharing (#20090) (Boshen) Co-authored-by: Boshen <1430279+Boshen@users.noreply.github.com>

overlookmotel mentioned this pull request Mar 6, 2026

refactor(linter/plugins): enable TS strict option #19675

Merged

overlookmotel mentioned this pull request Mar 6, 2026

chore(apps, napi): restrict global types to NodeJS in tsconfig #20064

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github-actions bot added A-linter Area - Linter A-cli Area - CLI A-ast-tools Area - AST tools A-linter-plugins Area - Linter JS plugins labels Mar 6, 2026

overlookmotel mentioned this pull request Mar 6, 2026

test(linter/plugins): add types test for VisitorObject #20066

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github-actions bot added the C-bug Category - Bug label Mar 6, 2026

overlookmotel marked this pull request as ready for review March 6, 2026 09:37

overlookmotel requested a review from camc314 as a code owner March 6, 2026 09:37

Copilot AI review requested due to automatic review settings March 6, 2026 09:37

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tasks/ast_tools/src/generators/estree_visit.rs Outdated Show resolved Hide resolved

overlookmotel marked this pull request as draft March 6, 2026 09:41

This was referenced Mar 6, 2026

refactor(linter/plugins): clarify types #20069

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refactor(linter/plugins): debug assert that values passed via NAPI are not undefined #20070

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overlookmotel changed the base branch from om/03-06-chore_apps_napi_restrict_global_types_to_nodejs_in_tsconfig to graphite-base/20065 March 6, 2026 14:37

overlookmotel force-pushed the graphite-base/20065 branch from a927c7c to e6b604f Compare March 6, 2026 14:37

overlookmotel force-pushed the om/03-06-fix_linter_plugins_fix_type_definition_for_visitorobject_ branch from 3a3d644 to cdae1ae Compare March 6, 2026 14:37

overlookmotel changed the base branch from graphite-base/20065 to main March 6, 2026 14:37

overlookmotel mentioned this pull request Mar 6, 2026

fix(linter/plugins): define RegExp.escape for tsc #20077

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overlookmotel force-pushed the om/03-06-fix_linter_plugins_fix_type_definition_for_visitorobject_ branch from cdae1ae to ecef907 Compare March 6, 2026 15:37

overlookmotel marked this pull request as ready for review March 6, 2026 15:40

overlookmotel requested a review from Copilot March 6, 2026 15:40

Copilot started reviewing on behalf of overlookmotel March 6, 2026 15:41 View session

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overlookmotel assigned camc314 Mar 6, 2026

camc314 approved these changes Mar 6, 2026

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camc314 added the 0-merge Merge with Graphite Merge Queue label Mar 6, 2026

graphite-app bot force-pushed the om/03-06-fix_linter_plugins_fix_type_definition_for_visitorobject_ branch from ecef907 to 602daaa Compare March 6, 2026 15:59

graphite-app bot merged commit 602daaa into main Mar 6, 2026
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graphite-app bot deleted the om/03-06-fix_linter_plugins_fix_type_definition_for_visitorobject_ branch March 6, 2026 16:07

graphite-app bot pushed a commit that referenced this pull request Mar 6, 2026

test(linter/plugins): add types test for VisitorObject (#20066)

aacfef4

Add a types test for #20065. This is a separate PR as it depends on `strict: true` TS config option added in #19675.

Boshen mentioned this pull request Mar 9, 2026

release(apps): oxlint v1.52.0 && oxfmt v0.37.0 #20143

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fix(linter/plugins): fix type definition for `VisitorObject`#20065

fix(linter/plugins): fix type definition for `VisitorObject`#20065
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