Commit Graph

147 Commits

Author SHA1 Message Date
camc314 4adfb4c949 fix(semantic): validate chained continue labels (#26157)
## Summary

- follow chained labels to their terminal statement when validating labeled `continue`
- reject label chains that terminate in a non-iteration statement
- add a focused negative coverage fixture and update the parser coverage snapshot
2026-08-28 18:45:13 +00:00
camc314 dc09a3aa9d fix(parser): avoid panic on escaped string export names (#26146)
## Summary

Fix a parser panic when a string-named export decodes to a literal `\u` sequence.

Lone-surrogate validation now uses the metadata captured by the lexer instead of rescanning decoded string contents. This also prevents false diagnostics for names such as `"\\uD800"`.

## Before:

```

thread 'main' (10990283) panicked at crates/oxc_ast/src/ast_impl/literal.rs:89:42:
end byte index 4 is out of bounds for string of length 0
stack backtrace:
   0: __rustc::rust_begin_unwind
   1: core::panicking::panic_fmt
   2: core::str::slice_error_fail_rt
   3: core::str::slice_error_fail
   4: <core::ops::range::RangeTo<usize> as core::slice::index::SliceIndex<str>>::index
   5: <str as core::ops::index::Index<core::ops::range::RangeTo<usize>>>::index
   6: <oxc_ast::ast::literal::StringLiteral>::is_string_well_formed_unicode
   7: <oxc_parser::ParserImpl<oxc_parser::config::NoTokensParserConfig>>::parse_module_export_name
```
2026-08-28 13:37:48 +00:00
Boshen fca2e0cfed fix(parser): reject initialized lexical declarations in for-in (#25700)
Rejects initialized `let` and `const` declarations in `for...in` during parsing while preserving Annex B's non-strict `var` form.

Adds misc coverage for valid and invalid initializer forms.

Verified with `just ready` and parser conformance.

Closes #25149.

AI-assisted.
2026-08-15 06:58:08 +00:00
Boshen ae9be8f8bd fix(parser): forbid type parameters on quoted constructors (#25696)
Quoted constructor methods bypassed the AST-based constructor validation. Validate type parameters after resolving the method key, preserving the AST shape.

Validation: `just ready`, parser conformance, and allocation checks.

Closes #25692.

AI-assisted with Codex.
2026-08-15 05:02:23 +00:00
Boshen cdf1846af2 fix(semantic): allow legacy escapes in JSX attributes (#25576)
Quoted JSX attribute values do not use ECMAScript escape sequences. Skip strict-mode legacy escape validation for JSX attributes and cover the behavior in misc conformance.

AI-assisted by Codex.
2026-08-13 07:06:42 +00:00
Boshen 23a7ad096a fix(parser): stop delimited lists at end of file (#25542)
Stop parsing delimited-list elements after a separator when EOF or an undetermined token follows, preventing malformed tuple syntax from creating reversed spans during error recovery.

Validated with `cargo coverage -- parser --filter oxc-23670 --detail`.

AI assistance was used to prepare this change.

Closes #23670.
2026-08-12 13:58:51 +00:00
Boshen 73acba93fb fix(parser): preserve fatal errors during await reparse (#25541)
Fixes #23681.

Preserve initial fatal parser errors during top-level `await` reparsing, preventing malformed recovery AST nodes from reaching Oxlint.

Validated with parser unit/conformance suites and allocation snapshots. `just ready` only fails three unrelated ANSI snapshot checks in the current environment.

AI-assisted.
2026-08-12 11:25:27 +00:00
Cameron 12937b3201 fix(parser): reject comma expressions in class fields (#25385)
## Summary

- parse ordinary class field initializers as `AssignmentExpression`
- reject unparenthesized comma expressions while preserving
parenthesized sequence expressions
- add paired misc conformance fixtures and update the generated
snapshots

## Root cause

Ordinary class field initializers used `parse_expr`, which accepts a
top-level comma and constructs a sequence expression. The ECMAScript
`Initializer` grammar requires an `AssignmentExpression`, so the
unparenthesized comma must remain for the class-element terminator check
to reject.
2026-08-08 10:59:23 +00:00
camc314 9e93ba6908 fix(parser): reset auto-accessor initializer context (#25384)
## Summary

- Align auto-accessor initializer parsing with class-field initializer grammar.
- Add regressions for `in` in a `for` initializer and disallowed inherited `await`/`yield` contexts.

## Root cause

The auto-accessor path only enabled `new.target`. It therefore inherited outer `~In`, `Await`, and `Yield` grammar contexts: `a in b` could not parse in a `for` initializer, while `await` and `yield` could incorrectly parse from enclosing async/generator functions. The fix applies the same `In | NewTarget` addition and `Yield | Await` removal already used for class fields, while retaining AssignmentExpression parsing.

## References

- [ECMAScript `FieldDefinition` grammar](https://tc39.es/ecma262/#prod-FieldDefinition)
- [ECMAScript `Initializer` grammar](https://tc39.es/ecma262/#prod-Initializer)
- [TC39 decorators proposal: class auto-accessors](https://github.com/tc39/proposal-decorators#introduction)
2026-08-07 23:03:24 +00:00
camc314 5c5cdcd522 feat(ast)!: narrow TSInterfaceHeritage::expression to TSTypeName (#24360)
## Summary

Narrow `TSInterfaceHeritage` from a general JavaScript `Expression` to `TSTypeName`.

```rust
pub struct TSInterfaceHeritage<'a> {
    pub type_name: TSTypeName<'a>,
    pub type_arguments: Option<Box<'a, TSTypeParameterInstantiation<'a>>>,
}
```

## Breaking Change

The Rust AST field changes from:

```rust
expression: Expression<'a>
```

to:

```rust
type_name: TSTypeName<'a>
```

## Why?

The current AST can represent shapes such as:

```ts
interface A extends foo() {}
interface A extends A + B {}
interface A extends new Foo() {}
interface A extends true {}
```

Which is an overly wide type since all of the above variants are invalid.

This PR tightens up the AST, making these invalid variants irrepresentable.

## How to migrate?

This should be a trivial migration:
1. instead of accessing `expression` on `TSInterfaceHeritage`, now access `type_name`
2. change any pattern matching on the `type_name` field to use `TypeName` (this is a smaller subset so should allow deleting code!)

closes https://github.com/oxc-project/backlog/issues/215
2026-08-07 06:00:42 +00:00
camc314 4d6f623cda feat(parser): emit error for type args in JS files (#24896)
## Summary

- Emit TS8011 when a JavaScript class heritage clause uses TypeScript type arguments.
- Cover the diagnostic with a misc parser failure fixture and snapshot.
2026-07-24 09:46:34 +00:00
Boshen 582805df03 fix(parser): parse unary conditional after satisfies (#24807)
Fixes #24804.

Recognize `!` as a type-start token so `?` after `satisfies` remains the conditional-expression operator instead of being consumed as a JSDoc nullable type.

Validated with `just ready`.

AI-assisted.
2026-07-22 13:22:14 +00:00
camc314 47ddedf011 fix(semantic): allow arguments in ambient declarations (#24758)
## Summary

- allow `eval` and `arguments` as direct bindings in ambient declarations
- continue reporting strict-mode errors for destructured ambient bindings
- add focused coverage for declared functions, classes, object patterns, and array patterns

## Why

The semantic checker previously identified allowed bindings by walking to a `TSDeclareFunction`. That missed other ambient declarations, including declared class constructors and methods, and produced diagnostics for TypeScript cases that require no runtime code generation.

The check now uses the existing ambient-context state and rejects only destructuring binding shapes.
2026-07-21 12:43:21 +00:00
camc314 129b759131 feat(parser): improve diagnostics for unparenthesized LHS on exponential expr (#24569)
## Summary

- Report operator-specific diagnostics when unary and `await` expressions are used as exponentiation left operands.
- Reject unparenthesized TypeScript type assertions in the same position while preserving explicitly parenthesized forms.
- Add regression fixtures and update the affected conformance snapshots.
2026-07-15 18:38:30 +00:00
camc314 7b4baff16c fix(parser): reject new import member access (#23459)
Reject `new import(...).prop`, `new import.source(...).prop`, and `new import.defer(...).prop` by treating member access on an unparenthesized import expression as invalid after `new`.

Fixes #23458
2026-07-15 10:38:34 +00:00
camc314 c517aa08a8 fix(parser): reject invalid accessor assertions (#24504)
## Summary

- Align auto-accessor definite assignment assertions with TypeScript.
- Report TS1263 when an accessor has both `!` and an initializer.
- Report TS1264 when an accessor has `!` but no type annotation.
- Report TS1255 for typed definite assertions in static, abstract, and ambient contexts.
- Highlight only the `!` token, matching TypeScript.

fixes #24503.

## TypeScript behavior

Given:

```ts
class A {
    accessor missingType!;
    // ^: TS1264: Declarations with definite assignment assertions must also have type annotations.
    accessor initialized! = 1;
    // ^: TS1263: Declarations with initializers cannot also have definite assignment assertions.
    accessor typed!: number;
    // ^: valid
    static accessor staticTyped!: number;
    // ^: TS1255: A definite assignment assertion '!' is not permitted in this context.
}
```

TypeScript treats auto-accessors as property declarations and applies the following grammar check:

https://github.com/microsoft/TypeScript/blob/637d5746b70257028fb95aad32ddec6b26ab0a14/src/compiler/checker.ts#L53443-L53452

This establishes the diagnostic precedence:

1. An initializer produces TS1263.
2. Otherwise, a missing type annotation produces TS1264.
3. Otherwise, an invalid context produces TS1255.
2026-07-14 10:16:51 +00:00
camc314 058a62f8a3 fix(semantic): track ambient contexts in SemanticBuilder (#24327)
## Summary

- track TypeScript ambient contexts using a nesting depth in `SemanticBuilder`
- enter ambient context for declaration files and `declare` declarations, including declarations without their own scope
- replace namespace-based and ancestry-based ambient detection
- use the ambient context for reserved keywords, global augmentations, class heritage, computed class members, and bodyless accessors
- extend conformance coverage for ambient variables, properties, functions, and classes

This approach was discussed with overlookmotel yesterday after some brainstorming!
2026-07-11 11:00:02 +00:00
camc314 1ebdce31b6 fix(semantic): allow reserved keywords in ambient declaration types (#24325)
Recognize identifiers nested within `declare` variable declarations and declared class properties as being in an ambient context.

This prevents valid TypeScript from incorrectly producing reserved-keyword diagnostics.

### Examples

Function types inside ambient variable declarations are now accepted:

```ts
declare let f: (package: number) => interface;
```

Type references inside declared class properties are also accepted:

```ts
class C {
  declare field: package;
}
```
Previously, package and interface were incorrectly reported as reserved keywords.
2026-07-09 10:40:33 +00:00
camc314 e8b50ee716 fix(transformer): clean up semantics for stripped TypeScript syntax (#24180)
## Summary

Keep transformer semantic data in sync when TypeScript-only syntax is removed.

This change:

- removes resolved and unresolved references belonging only to stripped TypeScript syntax
- removes bindings for erased type-only and unused imports
- preserves runtime bindings when a type import is merged with a value declaration
- promotes the surviving declaration’s symbol flags, span, and redeclaration metadata
- adds coverage for type imports merged with runtime declarations
- refreshes semantic and transformer conformance snapshots

## Motivation

We are preparing to change the AST shape, including adding and rearranging scopes.

Currently, transformer semantic snapshots contain thousands of lines of mismatches caused by stale bindings and references from TypeScript syntax that has already been removed from the AST. That creates a large amount of unrelated snapshot noise.

With that noise present, snapshot changes caused by the upcoming AST work would be difficult to review: a real scope or semantic regression could easily be hidden among mechanical churn.

This PR fixes the underlying semantic inconsistencies first, giving us a much cleaner baseline for reviewing future AST and scope changes. It is not intended to change emitted JavaScript.
2026-07-06 08:11:46 +00:00
sapphi-red 38c4b0628b feat(parser): add friendly error for adjacent JSX elements (#23378)
Add a friendly error for adjancent JSX element case:

```
  × Adjacent JSX elements must be wrapped in an enclosing tag.
   ╭─[misc/fail/jsx-adjacent-elements.jsx:3:3]
 2 │   <div />
 3 │   <span />
   ·   ─
 4 │ );
   ╰────
  help: Did you want a JSX fragment `<>...</>`?
```

This error message exists in babel.
2026-06-16 14:50:53 +00:00
camc314 1d3af58c4a feat(parser): add TS2398 parameter property diagnostic (#23216)
## Summary

- Report TS2398 when a TypeScript constructor parameter property is named `constructor`.
- Add coverage for the upstream TypeScript fixture plus dedicated misc pass/fail cases for ordinary `constructor` parameters versus invalid parameter properties.

```
  × TS(2398): 'constructor' cannot be used as a parameter property name.
   ╭─[misc/fail/oxc-ts-2398.ts:2:31]
 1 │ class A {constructor(public constructor){}}
 2 │ class B {constructor(readonly constructor){}}
   ·                               ───────────
   ╰────
```
2026-06-11 08:39:25 +00:00
camc314 8edd23459d fix(parser): report accessor definite assertion on token (#23203)
## Summary
- Pass the definite-assignment assertion token offset through the class accessor-property parser path.
- Report invalid ambient and abstract `accessor prop!` diagnostics on the `!` token, matching the span behavior used by variable declarators and normal class properties.
- Add focused misc parser coverage for the accessor-specific invalid cases.

## Rationale
This follows up #23170. That parser change already narrowed definite-assignment diagnostics for variables and normal class properties, but accessor properties still kept only a boolean. That meant `accessor prop!` could only report TS1255 using the full class element span. Carrying the offset into `parse_class_accessor_property` aligns accessor diagnostics with the other definite-assignment diagnostics and keeps the AST shape unchanged by storing only `definite.is_some()`.

The misc fixture is needed because upstream TypeScript coverage exercises invalid definite assertions on normal fields, but not invalid accessor properties. Existing misc coverage only had a valid `accessor y!` pass case, so `just coverage` did not specifically protect the accessor diagnostic span this fixes.
2026-06-10 07:46:45 +00:00
Boshen cf53285466 fix(parser): report reserved type-declaration names in the parser (#23035)
## What

Moves the reserved built-in type name check (a type's name may not be `any`, `string`, `number`, …) out of the semantic checker into the parser, via a reusable `check_reserved_type_name` helper. Covers **all** declaration forms:

- class → TS2414
- interface → TS2427
- type alias → TS2457
- enum → TS2431
- type parameter → TS2368

The semantic `check_type_name_is_reserved` helper and its diagnostic are removed.

## Why it moves cleanly

- **Zero state:** each is a name-vs-reserved-list match at the parse site where the identifier is parsed.
- **Node-final:** these declarations are never reinterpreted by cover grammar.
- **Negative-only:** confirmed by `cargo coverage` — no positive/negative count changes; only the errors relocating in `parser_typescript.snap`.

## Class needs an `is_ts` guard + a fixture fix

`class string {}` is valid JavaScript (these names are reserved only as *type* names), so the class check is guarded by `is_ts`. The interface/type-alias/enum/type-parameter forms are TypeScript-only parser paths, so they need no guard.

The `no-shadow-restricted-names` rule had `class undefined {}` / `(class undefined {})` fixtures. Since the lint test harness parses fixtures as TSX, those are now parse errors (TS2414). They're dropped — class-name shadowing is still covered by `class globalThis {}` (globalThis isn't a reserved type name), and `undefined` shadowing by the `var`/`import` fixtures.

## Verification

- `class number {}`, `interface any {}`, `type any = number`, `enum string {}`, `function f<any>() {}` → error; `class string {}` in `.js` → clean; valid names → clean.
- Parser/semantic/linter (1155) tests pass; clippy clean.

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2026-06-07 02:05:14 +00:00
Boshen 17e7cf3ce4 fix(parser): disallow unerasable as/satisfies assertions (#22986)
Port of [microsoft/typescript-go#4192](https://github.com/microsoft/typescript-go/pull/4192), which fixes [microsoft/TypeScript#63527](https://github.com/microsoft/TypeScript/issues/63527).

## Problem

`as`/`satisfies` are supposed to be erasable without changing runtime semantics. But for an expression of the form `a ## b as T $$ c`, where `##` has *lower* precedence than `$$`, erasing the assertion silently changes the parse:

```ts
const x = 1 + 1 as number * 2;
```

This parses as `((1 + 1) as number) * 2` (= `4`), but textually erasing `as number` yields `1 + 1 * 2` (= `3`). TypeScript now rejects such constructs as a syntax error, forcing explicit parentheses.

## Change

In `parse_binary_expression_rest`, after parsing an `as`/`satisfies` type, stop parsing if the following operator binds tighter than the operator that produced the running left-hand operand. This leaves the higher-precedence operator dangling and surfaces as a parse error.

A chained `a as T as U` keeps referring back to the original operator's precedence (the tracked precedence is intentionally not updated while consuming `as`/`satisfies`), so `1 + 1 as any as number * 2` is rejected too.

## Behavior

| Expression | Result |
| --- | --- |
| `1 as number * 2` | ok |
| `1 * 1 as number + 2` | ok (`+` does not bind tighter than `*`) |
| `1 + 1 as number * 2` | **error** |
| `1 + 1 as any as number * 2` | **error** |
| `1 >> 1 as number + 2` | **error** |
| `(1 + 1 as number) * 2` | ok |

`satisfies` behaves identically to `as`.

## Tests

Added `misc` coverage fixtures mirroring the upstream test matrix: `pass/ts-erasable-as-satisfies.ts` for the erasable cases and `fail/ts-unerasable-{as,as-chained,satisfies}.ts` for the rejected ones. Full conformance (test262 / babel / typescript) shows zero regressions.

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2026-06-05 13:10:42 +00:00
Boshen beb46d31fa fix(parser): commit to module goal on decorated exports (#22941)
## Summary

In unambiguous (`.js`) sources, `@foo export default class C { x = await + 1 }` reported a spurious `A module cannot have multiple default exports`.

A leading decorator makes the statement start with `@`, not `export`, so the eager Module-goal switch from #22684 didn't fire. The `await` identifier in the field initializer then triggered the unambiguous-mode top-level-await reparse, which re-ran `parse_statement_list_item` and recorded the `export default` a second time.

## Fix

- Commit to the Module goal in `parse_export_declaration` — the single place both leading and decorated exports flow through — so the export body parses under `Await` on the first pass, matching a non-decorated leading `export` (`ExportDeclaration` is unambiguously a `ModuleItem`, ECMA-262 §16.2.3).
- Skip the reparse for module declarations (`!stmt.is_module_declaration()`): an `export` / `import` is recorded on the first pass and is goal-independent, so reparsing only double-records it.

This also simplifies `parse_directives_and_statements`: the mutable `track_await_reparse` flag and the inline eager-commit block are removed; committing is now driven by `!ctx.has_await()`.

`await` stays correctly reserved in the module, so the input is still a syntax error (`The keyword 'await' is reserved`) — just no longer a *spurious* duplicate-export one. `tasks/coverage/misc/fail/oxc-22684.js` covers this.

Conformance: zero snapshot drift outside the new `misc` fixture.

Follow-up to #22684.

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2026-06-04 04:05:46 +00:00
sapphi-red 661132d5ac feat(parser): more friendly error messages for rest assignment target and rest binding element (#22719)
Made the errors for `({...[]} = {});` and `const {...[]} = obj;` a bit more easier to understand:

```
  × Invalid rest element target in destructuring assignment
   ╭─[misc/fail/rest-assignment-target.js:1:6]
 1 │ ({...[]} = {});
   ·      ──
   ╰────
  help: Expected an identifier or member expression, like `...rest` or `...obj.prop`.
```

```
  × Invalid rest element target in destructuring pattern
   ╭─[misc/fail/rest-binding-element.js:1:11]
 1 │ const {...[]} = obj;
   ·           ──
   ╰────
  help: Expected an identifier, like `...rest`.
```
2026-05-25 12:47:34 +00:00
camc314 e184f74d11 fix(parser): improve invalid import property access diagnostic (#22693)
This improves the parser diagnostic for invalid `import.<property>` access.

Previously, invalid properties like `import.sync("baz")` were reported as if only `import.meta` were valid, which is misleading now that `import.source()` and `import.defer()` are also supported.

Before:

```text
  × The only valid meta property for import is import.meta
    ╭─[index.ts]
 37 │
 38 │ import.foo();
      ──────────
 39 │
    ╰────
```

After:

```text
  × The only valid property accesses on import are `import.meta`, `import.source()`, and `import.defer()`
    ╭─[index.ts]
 37 │
 38 │ import.foo();
      ──────────
 39 │
    ╰────
```

Also adds a coverage fixture for the `import.sync("baz")` case and updates the parser coverage snapshots.
2026-05-25 09:58:50 +00:00
Boshen b284045af2 fix(parser): switch to module goal eagerly on export (#22684)
## Summary

In unambiguous (`.js` auto-detect) sources, `export var x = await + 1;` reported a spurious `Duplicated export 'x'` error. The parser first parsed the statement with `await` as an identifier, then re-parsed it under `Context::Await` to patch the AST — but the second pass re-invoked `visit_export_named_declaration`, recording the binding `x` a second time in the module record.

`export` is unambiguously module syntax per ECMA-262 §16.2.3 (`ExportDeclaration` is only a `ModuleItem`, never a Script production). So commit to the Module goal — enable `Context::Await` — as soon as the next top-level token is `Kind::Export`. The statement then parses correctly on the first attempt; no reparse and no duplicate record.

`Kind::Import` is intentionally **not** eager-switched. TypeScript's `import name = ns.path` is a script-compatible namespace alias (see `topLevelAwait.2.ts`), so treating `import` as a module starter would break that case.

The only TS snapshot churn is +16 lines of additional error messages for already-failing tests (`topLevelAwaitErrors.5.ts`, `topLevelAwaitErrors.6.ts` — `export ... await`). Summary counts unchanged.

Closes #22520
Fixes #22158
2026-05-23 06:00:04 +00:00
Boshen e431a0eb52 fix(parser): break extends clause loop on fatal error (#22517)
## Summary

`parse_extends_clause` kept iterating after `parse_lhs_expression_or_higher` set a fatal error, producing a `TSInterfaceHeritage` with an inverted span (`start > end`). `parse_class` then passed that span to `classes_can_only_extend_single_class`, which panicked in `miette` when converting the span to a label (`debug_assert!(self.start <= self.end)` in `Span::size`). Release builds silently produced garbage diagnostics.

Repro from the issue:

```js
class extends,{
```

Closes #22515

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2026-05-18 05:50:19 +00:00
camc314 9fa2122cef fix(parser): parse array computed class keys (#22159)
Fixes parser recovery for class computed property names whose expression starts with an array literal, such as `class C { [[]]() {} }`.

The TypeScript index-signature lookahead previously treated a nested `[` after the opening computed-name bracket as an unambiguous index signature. That caused valid class computed keys containing array literals to be parsed through the wrong branch and rejected.

This changes the lookahead so only `...` remains an early unambiguous index-signature signal, allowing nested arrays and other assignment expressions to parse as computed property names.

fixes: #22157
2026-05-05 20:46:22 +00:00
camc314 ffacf99cc1 fix(semantic): report error on await inside block inside static block (#20750) 2026-03-26 14:17:31 +00:00
camc314 ccf9301b93 fix(semantic): report error on for-await inside block inside static block (#20749) 2026-03-26 14:00:25 +00:00
camc314 78c264a783 fix(parser): fix conditional expressions with arrow-function alternates in TS (#20356)
fixes https://github.com/rolldown/rolldown/issues/8676
2026-03-14 07:18:30 +00:00
Boshen c205b0df51 fix(ast): remove ThisExpression from TSModuleReference (#18489)
## Summary

- Removes `ThisExpression` variant from `TSModuleReference` since `import x = this` is invalid TypeScript (error TS1359)
- Adds parser error when `this` is used in import equals declaration
- Updates codegen, transformer, and linter rules to handle the new enum structure

Closes #16841

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2026-01-24 15:25:10 +00:00
Boshen aed3669a02 fix(parser): parse HTML-like comments in unambiguous mode (#18442)
## Summary

Closes #18392

Support HTML-like comments (`<!--` and `-->`) per ECMAScript Annex B.1.1:

- **Script/CommonJS mode**: HTML comments recognized as single-line comments
- **Unambiguous mode (.js)**: HTML comments recognized; error deferred until ESM syntax detected
- **Module mode (.mjs)**: HTML comments at start of line emit "HTML comments are not allowed in modules" error; `<!--` in middle of expression (e.g. `foo <!--bar`) parses as operators

This enables proper detection of HTML comment injection vectors in security tools like [AikidoSec/zen-internals](https://github.com/AikidoSec/zen-internals/pull/125).

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2026-01-23 11:35:33 +00:00
overlookmotel 22b4d39bd5 test(semantic): add test cases for function redeclaration check (#18288)
Follow-on after #18231. Add test cases to make sure function redeclaration check works correctly in script, module, and CommonJS files.
2026-01-20 14:09:09 +00:00
Sysix 37482eba73 fix(parser): respect optional TSNamedTupleMember for ts error 1266 &1257 (#18178)
> This PR fixes TypeScript parser errors 1266 and 1257 by properly handling the `optional` field of `TSNamedTupleMember` when validating tuple element ordering constraints.

Introduced in #18146 and #18145
2026-01-18 11:35:35 +00:00
Boshen 91126a01a4 fix(parser): reparse all statements with await identifier in unambiguous mode (#18163)
## Summary

- Fix parsing of `await (...)` and other cases where `await` followed by
certain tokens was parsed as an identifier instead of an await
expression in unambiguous mode
- Commit 92e27b4 only handled `await /regex/` but missed other cases

## Changes

- Add `encountered_await_identifier` flag to `ParserState` to track when
await is parsed as identifier
- Set flag in `parse_identifier_reference` when parsing "await" as
identifier in non-await context
- Modify statement parsing to track checkpoints only for statements that
actually used await as identifier
- Once ESM detected, enable await context for remaining statements

## Test plan

- Added test cases in `tasks/coverage/misc/pass/`:
- `unambiguous-await-call.js` - Tests `await (async function () { })();`
- `unambiguous-await-in-declaration.js` - Tests `const x = await (async
function () { })();`
- All parser tests pass
- All conformance tests pass

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Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
2026-01-18 11:18:37 +08:00
Boshen 92e27b4e01 feat(parser): reparse await expressions in unambiguous mode when ESM detected (#18139)
## Summary

- Implements TypeScript-compatible await expression reparsing for unambiguous mode
- When `sourceType` is `unambiguous`, `await / 0 /u; export {}` now correctly parses as `await /0/u` (await expression with regex)
- Follows TypeScript's two-pass approach: initially parse `await` as identifier, then reparse with await context if ESM is detected

## Test plan

- Added `tasks/coverage/misc/pass/unambiguous-await-regex.js` test case
- Moved `tasks/coverage/misc/fail/babel-16776-s.js` to pass (now parses as division in script mode)
- All parser tests pass
- Conformance tests show improvements in parser_babel and semantic_babel

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2026-01-17 15:27:42 +00:00
Boshen 66b8c022ab feat(parser): implement unambiguous module parsing for JS/TS files (#18124)
## Summary

- Implements speculative/unambiguous parsing for `.js`, `.jsx`, `.ts`, and `.tsx` files
- Instead of assuming module or script upfront, parses with `ModuleKind::Unambiguous` and upgrades to module mode when ESM syntax is detected
- ESM indicators: `import`, `export`, `import.meta` (NOT top-level await alone)
- Defers top-level await errors until module type is resolved
- Vue loader upgrades unambiguous scripts to module mode
- Updates linter tests to use explicit ESM extensions (`.mjs`/`.mts`) where needed

## Test plan

- [x] All parser tests pass
- [x] All linter tests pass
- [x] All semantic tests pass
- [x] Coverage conformance tests updated

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2026-01-17 13:40:28 +00:00
Boshen fb181ccdff fix(semantic): error on using at top level in scripts (#18090)
## Summary

- Add check to error on `using` declarations at the top level of scripts
- `using` declarations require block scope semantics and are not allowed
at the top level of scripts

`using` declarations are allowed:
- At the top level of ES modules
- At the top level of CommonJS modules (files are wrapped in a function)
- Inside any block scope in scripts

But NOT at the top level of scripts.

Closes #11862

## Test plan

- [x] Added test case
`tasks/coverage/misc/fail/script-top-level-using.js` for invalid usage
- [x] Added test case
`tasks/coverage/misc/pass/script-using-in-block.js` for valid usage in
block
- [x] All existing tests pass

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Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
2026-01-17 12:18:26 +08:00
Boshen 08dad63678 feat(span): add sourceType: 'commonjs' support (#18089)
## Summary

- Add `ModuleKind::CommonJS` variant to support CommonJS module type in the parser
- Enable top-level `return` statements (CommonJS files are wrapped in a function)
- Enable top-level `new.target` (allowed in CommonJS function wrapper)
- Add proper errors for `import`/`export` statements in CommonJS
- Add proper errors for `import.meta` in CommonJS

The CommonJS source type can be set via:
- `SourceType::with_commonjs(true)` method
- Babel's `sourceType: "commonjs"` option

Closes #16200

## Test plan

- [x] Added test cases in `tasks/coverage/misc/pass/` for valid CommonJS features
- [x] Added test cases in `tasks/coverage/misc/fail/` for invalid CommonJS usage
- [x] Enabled Babel conformance tests for `sourceType: "commonjs"`
- [x] All existing tests pass

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2026-01-16 16:08:27 +00:00
Dunqing 4d9582d762 fix(semantic): allow arguments/eval as binding identifier names and identifier reference names in .d.ts (#17910)
Fixes: https://github.com/oxc-project/oxc/issues/17776
2026-01-12 10:03:42 +00:00
Copilot 59a6228ef9 fix(parser): detect TS1363 error for type-only imports with mixed default and named/namespace bindings (#17712)
The parser was not detecting `import type foo, {} from 'bar';` and `import type A, * as NS from 'mod';` as errors. TypeScript's TS1363 requires that type-only imports specify either a default import or named/namespace bindings, but not both—even when the named bindings list is empty.

## Changes

- **Parser**: Added TS1363 check in `parse_import_declaration_specifiers` when encountering `LCurly` or
`Star` token after a type-only default import
- **Module record**: Removed redundant TS1363 validation that couldn't detect empty `{}` cases
- **Error span**: Now points at the default specifier instead of the entire import statement

## Examples

The following patterns now correctly error with TS1363:

```typescript
// Empty named bindings
import type foo, {} from 'bar';

// Named bindings with specifiers
import type foo, { bar } from 'baz';

// Namespace import
import type A, * as NS from 'mod';
```

The parser-level check is comprehensive and catches all cases including
empty braces and namespace imports, which weren't being detected
previously.


- Fixes oxc-project/oxc#17684

---------

Signed-off-by: Cameron <cameron.clark@hey.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: camc314 <18101008+camc314@users.noreply.github.com>
Co-authored-by: Cameron <cameron.clark@hey.com>
2026-01-06 14:45:14 +00:00
camc314 d99134d70c feat(parser): improve diagnostic message for phase imports (#17092)
We now produce the same error codes as typescript
2025-12-21 08:14:16 +00:00
sapphi-red cb515fac28 feat(parser): improve error message for yield as identifier usage (#16950)
Improved error message for `yield` as identifier usage.

**Before**
```
  × Cannot use `yield` as an identifier in a generator context
    ╭─[test262/test/language/expressions/generators/yield-weak-binding.js:17:33]
 16 │
 17 │ var g = function*() { yield 3 + yield 4; };
    ·                                 ─────
    ╰────
```
**After**
```
  × Cannot use `yield` as an identifier in a generator context
    ╭─[test262/test/language/expressions/generators/yield-weak-binding.js:17:33]
 16 │
 17 │ var g = function*() { yield 3 + yield 4; };
    ·                                 ─────
    ╰────
  help: Wrap this in parentheses if you want to use a `yield` expression here
```
2025-12-16 11:30:44 +00:00
overlookmotel 75f9800166 test(parser): combine test cases for let as identifier (#16861)
Follow-on after #16840 and #16857. We had a few test cases relating to the same thing, and one of them called the undescriptive `oxc.js`. Combine them, and rename the test case files with a more accurate name.
2025-12-14 21:30:55 +00:00
Copilot d3208dc969 fix(parser): parse let?.x (#16840)
Fixes #16839.

Make parser parse `let?.x` successfully.

There's a failure in codegen idempotency tests, but that's an unrelated
and pre-existing bug, so am leaving that to another PR.

Co-authored-by: overlookmotel <theoverlookmotel@gmail.com>
2025-12-14 19:26:57 +00:00
sapphi-red da87812ac7 feat(semantic): add TS2309 error for export assignment with other exports (#15992)
Added TS2309 error check.
2025-12-06 08:30:06 +00:00
copilot-swe-agent 74cf5720bc feat(ast)!: Make source field of TSImportType a StringLiteral (#16114)
- [x] Change `source` field type in `TSImportType` from `TSType<'a>` to `StringLiteral<'a>` in `crates/oxc_ast/src/ast/ts.rs`
- [x] Remove `#[estree(via = TSImportTypeSource)]` attribute from the field
- [x] Run `just ast` to regenerate all derived code
- [x] Update the parser in `crates/oxc_parser/src/ts/types.rs` to parse a `StringLiteral` directly and emit errors for non-string literals
- [x] Delete the dead code `TSImportTypeSource` serializer from `crates/oxc_ast/src/serialize/ts.rs`
- [x] Add `ts_string_literal_expected` diagnostic (TS1141)
- [x] Update semantic snapshot for `import-type-with-type-params.snap`
- [x] Add test case for invalid import type source
- [x] Verify all tests pass
- [x] Simplify error recovery - just report error and create dummy string literal (per review feedback)
- [x] Fix spurious "Expected ')'" error by skipping invalid tokens in error recovery

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

<details>

<summary>Original prompt</summary>

>
> ----
>
> *This section details on the original issue you should resolve*
>
> <issue_title>AST: Make `source` field of `TSImportType` a `StringLiteral`</issue_title>
> <issue_description>Continuation of oxc-project/oxc#16074.
>
> The expression inside `import(...)` in TS context (`TSImportType`) cannot legally be anything other than a string literal.
>
> Our parser is too liberal. We currently accept all kind of crazy stuff like:
>
> ```ts
> type A = typeof import(`react`);
> type B = typeof import(A);
> type C = typeof import(`${A} ${B}`);
> type D = typeof import(typeof import('react'));
> ```
>
> [Playground](https://playground.oxc.rs/#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)
>
> TypeScript says these are all errors: [TS Playground](https://www.typescriptlang.org/play/?#code/C4TwDgpgBAglC8VSQPYDMoEsC2YUCdgAKAA3wgEMBjYEgSgG4AoZaAIQSXAnS1wOIxGLblADCnVrxx5CpACQBvGAF8oStivrNWUACKTu0-nKkYZAogHJy1YFbrCgA)
>
> ### AST change
>
> We should alter the type of the `source` field from `TSType<'a>` to `StringLiteral<'a>`:
>
> https://github.com/oxc-project/oxc/blob/35d0ee491cbcd271ebceaac7e25cff0490ded5c4/crates/oxc_ast/src/ast/ts.rs#L1382-L1389
>
> ```diff
> pub struct TSImportType<'a> {
>     pub span: Span,
> -   #[estree(via = TSImportTypeSource)]
> -   pub source: TSType<'a>,
> +   pub source: StringLiteral<'a>,
>     pub options: Option<Box<'a, ObjectExpression<'a>>>,
>     pub qualifier: Option<TSImportTypeQualifier<'a>>,
>     pub type_arguments: Option<Box<'a, TSTypeParameterInstantiation<'a>>>,
> }
> ```
>
> ### Parser changes
>
> If we change the AST first and run `just ast` to regenerate traits code, then all the places which rely on the type of `source` field will become apparent. We'll then need to alter the parser to throw an error if it encounters something that isn't a string literal.
>
> ### `ESTree` serialization
>
> Currently there's a custom deserializer to alter the AST on JS side from `TSType` to `StringLiteral`:
>
> https://github.com/oxc-project/oxc/blob/91eb3f2be509cef11cffeff51fac61a3a4fbd12c/crates/oxc_ast/src/serialize/ts.rs#L506-L538
>
> Once we've changed the field type in AST, this code can be deleted - it's dead code once `#[estree(via = TSImportTypeSource)]` attribute is removed from the `source` field in AST struct.</issue_description>
>
> ## Comments on the Issue (you are @copilot in this section)
>
> <comments>
> </comments>
>

</details>

- Fixes oxc-project/oxc#16111

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2025-11-25 18:51:16 +00:00