fix(linter/plugins): reset visitor compilation state if error during compilation by overlookmotel · Pull Request #20166 · oxc-project/oxc

overlookmotel · 2026-03-10T00:45:39Z

Fix a bug where internal state of visitor compilation could fail to be reset if an error is thrown during compilation, for example due to an invalid visitor being passed.

If this happens, previously some of the visitor functions defined for one file could stick around, and be erroneously included in the compiled visitor for next file, leading to them firing on that 2nd file when they shouldn't.

Fix that by resetting visitor compilation state in the try / catch which wraps the whole linting process.

overlookmotel · 2026-03-10T00:45:51Z

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Pull request overview

Fixes a JS-plugin linting bug where an exception during visitor compilation could leave compilation state “dirty”, causing visitor functions from a failed file to leak into subsequent files.

Changes:

Reset visitor compilation state on error by calling finalizeCompiledVisitor() from resetStateAfterError().
Add an end-to-end fixture that reproduces invalid-visitor compilation failure and asserts no visitor leakage across files.
Run the fixture single-threaded to make the file order deterministic for the test.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
apps/oxlint/src-js/plugins/lint.ts	Ensures visitor compilation state is cleaned up when `lintFile()` catches an error.
apps/oxlint/test/fixtures/lint_invalid_visitor/plugin.ts	Fixture plugin that intentionally returns an invalid visitor on the first file to trigger compilation failure.
apps/oxlint/test/fixtures/lint_invalid_visitor/output.snap.md	Snapshot asserting the compilation error is reported and only the second file’s visitor runs on file 2.
apps/oxlint/test/fixtures/lint_invalid_visitor/options.json	Forces `--threads 1` to make lint order deterministic for the fixture.
apps/oxlint/test/fixtures/lint_invalid_visitor/files/1.js	First file used to trigger the invalid visitor compilation path.
apps/oxlint/test/fixtures/lint_invalid_visitor/files/2.js	Second file used to verify no visitor bleed-through.
apps/oxlint/test/fixtures/lint_invalid_visitor/.oxlintrc.json	Enables the fixture plugin/rule for the test run.

apps/oxlint/src-js/plugins/lint.ts

graphite-app · 2026-03-10T01:46:09Z

Merge activity

Mar 10, 1:46 AM UTC: overlookmotel added this pull request to the Graphite merge queue.
Mar 10, 1:59 AM UTC: Merged by the Graphite merge queue.

…compilation (#20166) Fix a bug where internal state of visitor compilation could fail to be reset if an error is thrown during compilation, for example due to an invalid visitor being passed. If this happens, previously some of the visitor functions defined for one file could stick around, and be erroneously included in the compiled visitor for next file, leading to them firing on that 2nd file when they shouldn't. Fix that by resetting visitor compilation state in the `try` / `catch` which wraps the whole linting process.

In tests, run rules in a predictable order (the order they're defined in config). This makes it possible to control in tests with multiple rules in what order they run, which makes the tests in next 2 PRs (#20166, #20167) feasible.

Perf optimization to visitor compilation. Previously the flow for compiling and using a visitor was: 1. Call `initCompiledVisitor`. 2. Call `addVisitorToCompiled` with each visitor object. 3. Call `finalizeVisitor`. 4. Walk AST with compiled visitor. `initCompiledVisitor` resets state after previous compilation. Change this to: 1. Call `addVisitorToCompiled` with each visitor object. 2. Call `finalizeVisitor`. 3. Walk AST with compiled visitor. 4. Call `resetCompiledVisitor`. The difference is that resetting state now happens at *end* of linting a file, rather than at the start of linting the *next* file. The previous lifecycle design was motivated by needing to ensure state is reset even if an error is thrown during linting, but this case is now handled correctly by another means (#20166). The reset-at-the-end lifecycle makes more sense. It also has a perf benefit: Visit functions are freed earlier, so they can be garbage collected. This reduces the chance of ephemeral visit functions being pointlessly migrated to "old space" before they're deleted, which makes garbage collection cheaper. Also, they can now be garbage collected *between* linting files, while Rust side code is busy doing other tasks - rather than GC having to happen during linting on JS side, blocking main JS thread.

# Oxlint ### 🚀 Features - 04a5ce0 oxlint: Support `vite.config.ts` `.lint` field (#20214) (leaysgur) - 1735215 linter: Implement `react/no-clone-element` rule. (#20129) (connorshea) - 68e6f6f linter: Implement `react/no-react-children` rule. (#20104) (connorshea) - fe3b32e linter/plugins: Add `oxlint-plugin-eslint` package (#20009) (overlookmotel) ### 🐛 Bug Fixes - 05f6a09 linter/no-inline-comments: Deserialize rule options with serde (#20207) (camc314) - c7eb09d linter/default-case: Deserialize rule options with serde (#20206) (camc314) - f85e16c linter/plugins: Fix types for visitor compilation (#20203) (overlookmotel) - 44e24e0 linter/exhaustive-deps: Ignore type-only typeof deps (#20201) (camc314) - 0b04998 linter/no-fallthrough: Deserialize rule options with serde (#20192) (camc314) - a1031cb linter/new-cap: Deserialize rule options with serde (#20161) (camc314) - ad27fd6 linter: Add help messages to import plugin diagnostics (#20158) (John Costa) - 1340307 linter/plugins: Ensure `after` hooks always run (#20167) (overlookmotel) - c4812ec linter/plugins: Reset visitor compilation state if error during compilation (#20166) (overlookmotel) - 887eecc linter/plugins: Add license notice to `oxlint-plugin-eslint` package (#20164) (overlookmotel) - e1713a4 linter/plugins: Include common chunks in `oxlint-plugin-eslint` package (#20163) (overlookmotel) - a9acb2b linter: Check `globals` entry for `no-undef`, only check es2026 globals for `no-extend-native` and `no-constant-binary-expression` (#20089) (Sysix) - 5559f0d linter/no-unused-vars: `reportUsedIgnorePattern` should not report used rest siblings (#20108) (Don Isaac) - de7c0e2 linter/plugins: Correct error message for `markVariableAsUsed` (#20152) (overlookmotel) ### ⚡ Performance - 3a86427 linter/plugins: Pre-populate cache of `EnterExit` objects at startup (#20194) (overlookmotel) - d243391 linter/plugins: Replace arrays with `Uint8Array`s (#20190) (overlookmotel) - 8742f8b linter/plugins: Pre-populate cache of `VisitProp` objects (#20189) (overlookmotel) - 3061acb linter/plugins: Pre-populate cache of `EnterExit` objects (#20187) (overlookmotel) - c73912b linter/plugins: Free visit functions earlier (#20186) (overlookmotel) - d9f8ff4 linter/plugins: Faster reset of visitor state (#20185) (overlookmotel) - 42aff15 oxlint/lsp: Avoid computing diagnostics for non invoked code actions requests (#20080) (Sysix) ### 📚 Documentation - a080650 linter/plugins: Fix documentation of visitor compilation (#20202) (overlookmotel) - 542a04a linter: Add a link to the cyclomatic complexity Wikipedia article in `eslint/complexity` (#20174) (connorshea) # Oxfmt ### 🚀 Features - 95943aa oxfmt: Support `vite.config.*` `.fmt` field (#20197) (leaysgur) - 172fc07 oxfmt: .js/.ts config file support (#20135) (leaysgur) ### 🐛 Bug Fixes - e483569 oxfmt: Avoid double-escaping in css-in-js (#20211) (leaysgur) Co-authored-by: leaysgur <6259812+leaysgur@users.noreply.github.com>

This was referenced Mar 10, 2026

test(linter/plugins): run rules in predictable order in tests #20165

Merged

fix(linter/plugins): ensure after hooks always run #20167

Merged

github-actions bot added A-linter Area - Linter A-cli Area - CLI A-linter-plugins Area - Linter JS plugins C-bug Category - Bug labels Mar 10, 2026

overlookmotel marked this pull request as ready for review March 10, 2026 00:54

overlookmotel requested a review from camc314 as a code owner March 10, 2026 00:54

Copilot AI review requested due to automatic review settings March 10, 2026 00:54

Copilot started reviewing on behalf of overlookmotel March 10, 2026 00:54 View session

Copilot AI reviewed Mar 10, 2026

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apps/oxlint/src-js/plugins/lint.ts Show resolved Hide resolved

overlookmotel self-assigned this Mar 10, 2026

overlookmotel force-pushed the om/03-09-fix_linter_plugins_reset_visitor_compilation_state_if_error_during_compilation branch from 69d2c89 to 02cc349 Compare March 10, 2026 01:16

overlookmotel force-pushed the om/03-09-test_linter_plugins_run_rules_in_predictable_order_in_tests branch from fdb28de to 425b8be Compare March 10, 2026 01:16

graphite-app bot added the 0-merge Merge with Graphite Merge Queue label Mar 10, 2026

graphite-app bot force-pushed the om/03-09-test_linter_plugins_run_rules_in_predictable_order_in_tests branch from 425b8be to 3dabb8e Compare March 10, 2026 01:46

graphite-app bot force-pushed the om/03-09-fix_linter_plugins_reset_visitor_compilation_state_if_error_during_compilation branch from 02cc349 to c4812ec Compare March 10, 2026 01:47

Base automatically changed from om/03-09-test_linter_plugins_run_rules_in_predictable_order_in_tests to main March 10, 2026 01:58

graphite-app bot merged commit c4812ec into main Mar 10, 2026
20 checks passed

graphite-app bot deleted the om/03-09-fix_linter_plugins_reset_visitor_compilation_state_if_error_during_compilation branch March 10, 2026 01:59

graphite-app bot removed the 0-merge Merge with Graphite Merge Queue label Mar 10, 2026

overlookmotel mentioned this pull request Mar 10, 2026

perf(linter/plugins): free visit functions earlier #20186

Merged

Boshen mentioned this pull request Mar 11, 2026

release(apps): oxlint v1.53.0 && oxfmt v0.38.0 #20218

Merged

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fix(linter/plugins): reset visitor compilation state if error during compilation#20166

fix(linter/plugins): reset visitor compilation state if error during compilation#20166
graphite-app[bot] merged 1 commit intomainfrom
om/03-09-fix_linter_plugins_reset_visitor_compilation_state_if_error_during_compilation

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