feat(parser): parse unambiguous await with better error messages#18480
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Pull request overview
This PR enhances the parser to detect and handle unambiguous await expressions, aligning with Babel's behavior. The changes improve error messages and allow top-level await to properly upgrade files to ESM in unambiguous parsing mode.
Changes:
- Added
is_unambiguous_await()method to detect whenawaitis clearly an await expression (not an identifier) - Implemented function depth tracking to differentiate between top-level and function-level await usage
- Modified await expression parsing to upgrade files to ESM when unambiguous top-level await is detected (similar to Babel's
sawUnambiguousESM)
Reviewed changes
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Show a summary per file
| File | Description |
|---|---|
crates/oxc_parser/src/state.rs |
Added encountered_unambiguous_await flag and function_depth counter to parser state |
crates/oxc_parser/src/module_record.rs |
Added found_unambiguous_await() method to mark files as ESM |
crates/oxc_parser/src/js/statement.rs |
Integrated unambiguous await detection into statement parsing to upgrade to ESM |
crates/oxc_parser/src/js/function.rs |
Added function depth tracking when parsing function bodies |
crates/oxc_parser/src/js/arrow.rs |
Added function depth tracking for arrow function expression bodies |
crates/oxc_parser/src/js/expression.rs |
Rewrote await expression parsing with three distinct cases: await context, unambiguous await, and ambiguous await |
tasks/coverage/snapshots/*.snap |
Updated test snapshots showing improved conformance and better error messages |
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) ## Summary - Add `is_unambiguous_await()` to detect when `await x` is clearly an await expression - Unambiguous top-level await upgrades file to ESM (like Babel's `sawUnambiguousESM`) - Add `function_depth` tracking so await inside non-async functions errors even in ESM - Treat `await of` and `await using` as ambiguous (for-await-of and await using declarations) - Better error messages: "await is only allowed within async functions" instead of confusing "Expected semicolon" errors Closes #15541 Closes #18457 🤖 Generated with [Claude Code](https://claude.ai/code)
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### 💥 BREAKING CHANGES - 22dec6a semantic: [**BREAKING**] Remove `Scoping::scope_build_child_ids` and all related APIs (#18362) (Dunqing) - 30a4899 oxc: [**BREAKING**] Remove `CompilerInterface::semantic_child_scope_ids` (#18361) (Dunqing) - 777fc40 ast: [**BREAKING**] Add `Ident` type (#18354) (Boshen) - af0ca46 span: [**BREAKING**] Use `ModuleKind::CommonJS` for `SourceType::cjs()` (#18276) (sapphi-red) ### 🚀 Features - 0a02026 semantic: Add TS1499 code to diagnostic (#18557) (camc314) - 8b4618f parser: Add TS1500 code to diagnostic (#18547) (camc314) - 866b6b3 parser: Add TS1048 code to diagnostic (#18546) (camc314) - 1117c44 parser: Add TS1054 code to diagnostic (#18541) (camc314) - e4fcdde semantic: Add TS1053 code to diagnostic (#18539) (camc314) - bcbf396 semantic: Add TS1052 code to diagnostic (#18538) (camc314) - 8155edf semantic: Add TS1049 code to diagnostic (#18535) (camc314) - 51d3b3f parser: Add TS1502 code to diagnostic (#18534) (camc314) - 00854e8 semantic: Add TS2337 error code to super call diagnostic (#18531) (camc314) - 993fd2b parser: Parse unambiguous await with better error messages (#18480) (Boshen) - 8db0e78 linter/plugins: Handle BOMs (#18376) (overlookmotel) - 6ac09e2 linter/plugins: Support source text not being at start of buffer (#18375) (overlookmotel) - 2ef5647 ast: Add escape_raw parameter to template_element builders (#18121) (Boshen) ### 🐛 Bug Fixes - 74d0998 semantic: Update error msg for multiple `default` cases in switch stmt (#18526) (camc314) - c205b0d ast: Remove `ThisExpression` from `TSModuleReference` (#18489) (Boshen) - aed3669 parser: Parse HTML-like comments in unambiguous mode (#18442) (Boshen) - c4132fb parser: Validate accessor parameters in interface method signatures (#18391) (Boshen) - b0cd74d semantic: Allow `var` and `function` with same name in static blocks (#18358) (Boshen) - 6037995 semantic: Allow `new.target` in class field initializers (#18349) (Boshen) - 9a15c6a semantic: Do not rely on spans for node comparison in `Function::bind` (#18296) (overlookmotel) ### ⚡ Performance - 6b600c4 semantic: Skip parent lookup for function declarations in `Function::bind` (#18293) (overlookmotel) - c27ad2d semantic: Move check for function declaration out of `is_function_part_of_if_statement` (#18292) (overlookmotel) - 63eb89e semantic: Skip checking redeclarations for function expressions (#18291) (overlookmotel) - 7c12743 semantic: Skip checking unresolved exports in CommonJS files (#18250) (overlookmotel) - 2349031 allocator: Increase initial chunk size from 512B to 16KB (#18234) (Boshen) ### 📚 Documentation - 8ccd853 npm: Update package homepage URLs and add keywords (#18509) (Boshen) - 9b3165f napi/parser: Clarify when to use `parseAsync` vs `parseSync` (#18486) (Boshen) - 1b59f63 napi/parser: Correct typo in README (#18251) (overlookmotel) - 00ff75f mangler: Fix `top_level` option in example (#18233) (overlookmotel) - 2ddc073 semantic: Fix typo in comment (#18238) (overlookmotel) Co-authored-by: Boshen <1430279+Boshen@users.noreply.github.com>
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# Oxlint ### 💥 BREAKING CHANGES - 777fc40 ast: [**BREAKING**] Add `Ident` type (#18354) (Boshen) ### 🚀 Features - 34c3ec3 linter/prefer-logical-operator-over-ternary: Implement fixer (#18545) (camc314) - 019e0aa linter/valid-typeof: Add suggestions if type is misspelled (#18543) (camchenry) - 704c8eb linter/use-isnan: Add more specific error message for equality/inequality (#18542) (camchenry) - 1e99ace linter/use-isnan: Support more `indexOf` cases and improve diagnostic messages (#18537) (camchenry) - bffd134 linter/text-encoding-identifier-case: Add `withDash` option (#18533) (camc314) - 993fd2b parser: Parse unambiguous await with better error messages (#18480) (Boshen) - b4b6247 linter/plugins: `RuleTester` support settings (#18445) (overlookmotel) - 15d69dc linter: Implement react/display-name rule (#18426) (camchenry) - 2fbceae linter: Implement rule docs and config support for rules with tuple config options. (#18372) (connorshea) - 8db0e78 linter/plugins: Handle BOMs (#18376) (overlookmotel) - 6ac09e2 linter/plugins: Support source text not being at start of buffer (#18375) (overlookmotel) - fc3c86b linter: Update 125 rules to raise errors when provided with invalid config options. (#18104) (connorshea) - 2cc6ad2 linter/plugins: Add `ecmaFeatures` to `parserOptions` (#18313) (overlookmotel) ### 🐛 Bug Fixes - 2acf568 linter/plugins: Keep `Infinity` in rule default options (#18550) (overlookmotel) - 332d2ef linter/plugins: Add `jsx` property to `parserOptions.ecmaFeatures` (#18549) (overlookmotel) - 7d9bb1b linter: Update `eslint/func-names` to error on invalid rule config options, improve docs. (#18510) (connorshea) - 9c67974 linter: Improve the jsx-a11y/no-noninteractive-tabindex rule to match original rule logic better (#17848) (connorshea) - 75e7163 vscode: Support json5 for oxfmt (#18502) (Sysix) - c205b0d ast: Remove `ThisExpression` from `TSModuleReference` (#18489) (Boshen) - c51339a oxlint/lsp: Respect code action `source.fixAll` as an alias for `source.fixAll.oxc` (#18366) (Sysix) - 3c0e9b9 oxlint/lsp: Skip dangerous fixes/suggestions for "fix all" code action and command (#18364) (Sysix) - c44c093 linter: Fix behavior of unicorn/catch-error-name to match original rule (#18209) (connorshea) - 9c65aff linter/jsx-a11y: Change `no-autofocus` autofix to suggestion (#18155) (Ben Lowery) - 235c820 linter/unicorn: Fix `prefer-array-some` autofix for `.filter().length` pattern (#18153) (Ben Lowery) - a9925dc linter: Mark fixes in `unicorn/no-null` rule as dangerous. (#18436) (connorshea) - cee29b4 linter: Remove confusing scope from `react/only-export-components` rule diagnostics. (#18434) (connorshea) - aed3669 parser: Parse HTML-like comments in unambiguous mode (#18442) (Boshen) - b8a371d linter: Fix the path used in the gitlab format output (#18165) (connorshea) - e046ea6 linter: `vue/no-lifecycle-after-await` skip looking into arrow functions (#18302) (Sysix) - a9bfbcf linter: Compatibility issue with `DiagnosticData` type in ESLint (#18396) (루밀LuMir) - 10ab424 linter: `react/no_array_index_key` continue search for other attributes (#18409) (Lonami) - 9d776d4 linter: Update `import/no-cycle` rule to error on invalid config options. (#18330) (connorshea) - c163231 linter: Update eslint/sort-imports to validate options. (#18378) (connorshea) - 79bbcff linter: Update `eslint/func-style` to error on invalid configuration options. (#18390) (connorshea) - b871235 linter/plugins: Fix identifying "use strict" directives in scope analysis (#18402) (overlookmotel) - 5985141 linter: Update `jest/prefer-lowercase-title` rule to error on invalid config options. (#18332) (connorshea) - faca4b5 linter/plugins: Tokenize `let`, `static` and `yield` as `Keyword`s (#18368) (overlookmotel) - a3914fd linter/plugins: Allow line number passed to `report` to be 1 over line count (#18341) (overlookmotel) - 88e0896 linter: Update `typescript/no-restricted-types` rule to error on invalid config options. (#18329) (connorshea) - 9eec600 linter: Update `react/jsx-fragments` rule to raise an error on invalid configuration options (#18111) (connorshea) - 0fa969d linter: Update `react/no-will-update-set-state` to error on invalid config options (#18112) (connorshea) - 70e7be4 linter: Update `import/no-unassigned-import` to raise an error when passed invalid config options. (#18108) (connorshea) - 496cac7 linter: Update `unicorn/explicit-length-check` to raise an error when passed invalid config options. (#18107) (connorshea) - 080b1ec linter: Update 5 more rules to error on invalid config options. (#18113) (connorshea) - c5d05dd linter: Update 11 rules to raise an error on invalid config options. (#18109) (connorshea) - 9e359d4 linter/plugins: Set all properties on global vars objects (#18317) (overlookmotel) - 39c7f32 linter/plugins: Set `writeable` flag on variables where defined as globals (#18316) (overlookmotel) - a570693 linter/plugins: Fix `CatchClause` scopes (#18312) (overlookmotel) - 8c98e69 linter: `vitest/prefer-describe-function-title`: Check earlier to avoid false positive (#18177) (Jovi De Croock) - 44be0eb linter/plugins: Set scope analyse settings based on source type (#18306) (overlookmotel) - b9a14fd vscode: Update package.json to restrict a few more config options. (#18270) (Connor Shea) - c1260cb vscode: Update version info formatting. (#18274) (connorshea) - 2f68dc6 vscode: Update notification for client restart to specify tool. (#18273) (connorshea) ### ⚡ Performance - dc931ba linter/no-inner-declarations: Skip scope flags lookup in modules (#18249) (overlookmotel) - 07618a7 linter: Turn off `scope_build_child_ids` for SemanticBuilder (#18360) (Dunqing) - 1aac079 linter/exhaustive-deps: Simplify the logic of checking if the identifier it is a dependency of hook (#18350) (Dunqing) - 591d522 linter/block-scoped-var: Avoid `iter_all_scope_child_ids` by walking references/redeclarations scope ancestors (#18335) (Dunqing) - 2eefd6d linter/plugins: Remove branch from token parsing (#18369) (overlookmotel) ### 📚 Documentation - 698c21d linter: Modernize docs for various React rules (#18559) (connorshea) - 314a47c linter: Clarify the `no-find-dom-node` rule with a note that the method was removed in React 19. (#18556) (connorshea) - 5eff704 linter: Update `no-inner-declarations` to fix config option docs (#18511) (connorshea) - dd5d2f6 linter: Improve diagnostic message in `valid_typeof` rule. (#18507) (connorshea) - 8ccd853 npm: Update package homepage URLs and add keywords (#18509) (Boshen) - 4958233 linter: Add missing "What it does" section in prefer-reflect-apply rule. (#18475) (connorshea) - 2fa83a4 linter: Improve the docs for import/unambiguous. (#18474) (connorshea) - 7b1505c linter: Improve docs for `oxc/only-used-in-recursion` rule. (#18473) (connorshea) - ab506d6 linter/plugins: Correct comment (#18456) (overlookmotel) - 4565c73 linter: `react/display-name`: add docs for config options (#18430) (camchenry) - b95a89f linter: Fix docs for the curly rule. (#18374) (connorshea) - f675eb4 linter: Fix the `react/only-export-components` rule docs. (#18319) (connorshea) - 704db95 linter: "no-unused-vars" extend ignored files section for svelte and astro files (#18304) (Sysix) - 3af4a88 linter: Add "Examples" headers to rules missing them (#18266) (connorshea) # Oxfmt ### 💥 BREAKING CHANGES - 777fc40 ast: [**BREAKING**] Add `Ident` type (#18354) (Boshen) ### 🚀 Features - d71c15d oxfmt: Enable tailwind sort inside xxx-in-js (#18417) (leaysgur) - 52b5003 formatter,oxfmt: Support Angular `@Component({ template, styles })` (#18324) (leaysgur) ### 🐛 Bug Fixes - 224140c oxfmt: Canonicalize `..` component in config path (#18570) (leaysgur) - 30b467e formatter: Preserve trailing comments before the semicolon in class methods without a body (#18446) (Dunqing) - c205b0d ast: Remove `ThisExpression` from `TSModuleReference` (#18489) (Boshen) - 164bbd7 formatter: Preserve trailing comments inside ternary alternate branch (#18433) (Dunqing) - 1c50800 formatter: Use HTML entity escaping for JSX attribute strings (#18385) (Boshen) - 4e156d2 formatter: Preserve parentheses for `in` expressions in arrow function block bodies (#18352) (Boshen) - 7e6c15b oxfmt: Increase Tailwind CSS test timeout for Windows CI (#18339) (Boshen) - 29966eb formatter/dead-code-removal: Handle tailwind sorting (#18321) (leaysgur) - 29f41be formatter: Only expand mapped types when newline immediately follows opening brace (#18087) (Boshen) - 2194552 formatter: Relocate leading comments for single-element union/intersection types (#18083) (Boshen) ### ⚡ Performance - 85ab400 formatter: Store `AstNodes` itself instead of `&'a AstNodes` as the `parent` field of `AstNode` (#18428) (Dunqing) - 194d384 formatter: Reduce AstNode size by 8 bytes using following_span_start (#18347) (Dunqing) - b2df8fb oxfmt: Enable tailwind plugin only for relevant parser (#18418) (leaysgur) ### 📚 Documentation - 8ccd853 npm: Update package homepage URLs and add keywords (#18509) (Boshen) Co-authored-by: Boshen <1430279+Boshen@users.noreply.github.com>
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Summary
is_unambiguous_await()to detect whenawait xis clearly an await expressionsawUnambiguousESM)function_depthtracking so await inside non-async functions errors even in ESMawait ofandawait usingas ambiguous (for-await-of and await using declarations)Closes #15541
Closes #18457
🤖 Generated with Claude Code