fix(parser): report new.target and import.meta syntax errors in the parser#23003
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…he parser (#23003) ## What Move the `MetaProperty` early-error checks from the semantic checker (`oxc_semantic`) into the parser: - **`new.target` outside a valid context** — e.g. at the top level, in a top-level arrow, or in a computed class-member key. - **`import.meta` outside a module** — i.e. in script / CommonJS code. Consumers that only run the parser (without `SemanticBuilder`) now get these diagnostics. ## How - `new.target` validity is tracked with a new inherited `Context::NewTarget` flag (widening `Context` from `u8` to `u16`). The flag is *added* by three constructs — a regular (non-arrow) function's parameters + body, a class static block, and a class field initializer — and *inherited* through arrow functions and class bodies. This naturally models the spec rule, including cases like `function g(){ class D { [new.target](){} } }` (valid, inherits `g`'s context). - `import.meta` reuses the existing `error_on_script` deferral, so in unambiguous source `visit_import_meta` marks the file a module and the deferred error is discarded. - `check_meta_property` and its now-unused diagnostics are removed from `oxc_semantic`. ## Spec correctness Verified all cases against V8 (Node v24). One behavior change vs. the old semantic checker: a computed class **field** key such as `class C { [new.target] = 1 }` at the top level is now correctly a **SyntaxError**, matching V8 — the old checker accepted it due to a coarse `PropertyDefinition` AST-ancestor match. | Source | V8 | this PR | | --- | --- | --- | | `new.target;` | SyntaxError | error | | `function f(){ new.target; }` | ok | ok | | `() => new.target;` | SyntaxError | error | | `class C { x = new.target; }` | ok | ok | | `class C { static { new.target; } }` | ok | ok | | `class C { [new.target] = 1; }` | SyntaxError | error | | `class C { [new.target](){} }` | SyntaxError | error | | `function g(){ class D { [new.target](){} } }` | ok | ok | | `import.meta` in script | SyntaxError | error | | `import.meta` in module | ok | ok | Parser & semantic conformance remain 100% positive / 100% negative on test262; all unit tests pass. 🤖 Generated with [Claude Code](https://claude.com/claude-code)
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### 💥 BREAKING CHANGES - ee4dc73 ast: [**BREAKING**] Add `#[non_exhaustive]` to AST nodes (#23046) (overlookmotel) - 4c35362 ast: [**BREAKING**] Add `AstBuilder::template_element_escape_raw` and `template_element_escape_raw_with_lone_surrogates` methods (#23047) (overlookmotel) ### 🚀 Features - b846ab2 react_compiler: Integrate the Rust port of the React Compiler (#22942) (Boshen) - 5b8dd68 parser: Report TS1255 for invalid class definite assertions (#22917) (camc314) - 85efabf semantic: Make building the class table optional, off by default (#22862) (Boshen) ### 🐛 Bug Fixes - 556acdc codegen: Parenthesize TS-cast assignment targets (#23112) (Boshen) - 37169ff codegen: Don't emit space between postfix `--` and `>` when minifying (#23036) (Boshen) - a4b1bf7 codegen: Drop redundant whitespace in minified TypeScript output (#23038) (Boshen) - cf53285 parser: Report reserved type-declaration names in the parser (#23035) (Boshen) - 4e44969 ast: Fix UB in `escape_template_element_raw` (#23052) (overlookmotel) - c543154 parser: Report comma operator in JSX expression in the parser (#23030) (Boshen) - 325c94f codegen: Tighten conditional-type and constructor-type whitespace when minifying (#23033) (Boshen) - 95dd3a2 parser: Report `import type` alias to a non-external reference in the parser (#23032) (Boshen) - 90180b8 codegen: Drop space after `:` in function return type when minifying (#23028) (Boshen) - 6da876e parser: Report `abstract` private class field in the parser (#23029) (Boshen) - 28467ce codegen: Don't emit space before a postfix update operand when minifying (#23027) (Boshen) - cb29926 codegen: Drop redundant space after `export default` when minifying (#23024) (Boshen) - 62965ae codegen: Drop redundant space after `else` when minifying (#23025) (Boshen) - 989230a parser: Report compound assignment to non-simple target in the parser (#23022) (Boshen) - 06f367c parser: Report `super.#field` private access in the parser (#23014) (Boshen) - 184edef codegen: Print space before `const`/`declare` enum modifier (#23013) (Boshen) - 4d722e0 parser: Report duplicate switch `default` clause in the parser (#23012) (Boshen) - 597ed85 codegen: Parenthesize `let`/`async` for-of head target (#23008) (Boshen) - 8b631bf codegen: Remove stray space before mapped type value colon (#23010) (Boshen) - c08407e codegen: Don't over-parenthesize `in` inside an arrow in a for-init (#23009) (Boshen) - 600cd6f codegen: Parenthesize lower-precedence `TSInstantiationExpression` operand (#23007) (Boshen) - 187e1a5 codegen: Don't leak space after comment-only JSX expression container (#23006) (Boshen) - 294c473 codegen: Don't over-parenthesize `TSTypeAssertion` operand (#23004) (Boshen) - 786d96f codegen: Give `TSTypeAssertion` unary precedence (#23002) (Boshen) - 1295882 parser: Report `new.target` and `import.meta` syntax errors in the parser (#23003) (Boshen) - d727b6b codegen: Parenthesize `await` expression as base of `**` (#23001) (Boshen) - 67dfa08 codegen: Keep parentheses around `new` callees containing a call (#22997) (Boshen) - 17e7cf3 parser: Disallow unerasable `as`/`satisfies` assertions (#22986) (Boshen) - beb46d3 parser: Commit to module goal on decorated exports (#22941) (Boshen) - 49e63f7 isolated-declarations: Require annotations for satisfies initializers (#22898) (camc314) - 8c93601 isolated-declarations: Allow unknown enum initializer in non-const enum (#22900) (camc314) ### ⚡ Performance - 7d89909 parser: Peek instead of lookahead for yield disambiguation (#23071) (Boshen) - bf872f0 parser: Skip arrow lookahead for a parenthesized literal (#23070) (Boshen) - d19fc54 parser: Guard type-argument speculation behind an angle-token check (#23069) (Boshen) - 8eb5507 parser: Skip redundant member-rest re-scan on call entry (#23068) (Boshen) - 883dfc1 parser: Skip parse_call_expression_rest when no call follows (#23063) (Boshen) - b171153 parser: Peek before the await-using lookahead (#23059) (Boshen) - 56f21bd parser: Use peek_token for the TS `asserts` type predicate (#23058) (Boshen) - 68805ac parser: Use peek_token instead of checkpoint/rewind for single-token decisions (#23056) (Boshen) - 1f9d8eb ast: `AstBuilder::template_element_escape_raw` avoid allocation if no escape required (#23053) (overlookmotel) - 502b04d semantic: Move cold function redeclaration handling into `#[cold]` function (#22973) (overlookmotel) ### 📚 Documentation - 275d318 napi/minifier: Point `target` to oxc docs (#23102) (camc314) Co-authored-by: Boshen <1430279+Boshen@users.noreply.github.com>
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What
Move the
MetaPropertyearly-error checks from the semantic checker (oxc_semantic) into the parser:new.targetoutside a valid context — e.g. at the top level, in a top-level arrow, or in a computed class-member key.import.metaoutside a module — i.e. in script / CommonJS code.Consumers that only run the parser (without
SemanticBuilder) now get these diagnostics.How
new.targetvalidity is tracked with a new inheritedContext::NewTargetflag (wideningContextfromu8tou16). The flag is added by three constructs — a regular (non-arrow) function's parameters + body, a class static block, and a class field initializer — and inherited through arrow functions and class bodies. This naturally models the spec rule, including cases likefunction g(){ class D { [new.target](){} } }(valid, inheritsg's context).import.metareuses the existingerror_on_scriptdeferral, so in unambiguous sourcevisit_import_metamarks the file a module and the deferred error is discarded.check_meta_propertyand its now-unused diagnostics are removed fromoxc_semantic.Spec correctness
Verified all cases against V8 (Node v24). One behavior change vs. the old semantic checker: a computed class field key such as
class C { [new.target] = 1 }at the top level is now correctly a SyntaxError, matching V8 — the old checker accepted it due to a coarsePropertyDefinitionAST-ancestor match.new.target;function f(){ new.target; }() => new.target;class C { x = new.target; }class C { static { new.target; } }class C { [new.target] = 1; }class C { [new.target](){} }function g(){ class D { [new.target](){} } }import.metain scriptimport.metain moduleParser & semantic conformance remain 100% positive / 100% negative on test262; all unit tests pass.
🤖 Generated with Claude Code