fix(parser): report compound assignment to non-simple target in the parser#23022
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…arser (#23022) ## What Moves the "Invalid left-hand side in assignment" check (a compound assignment operator requires a simple target) out of the semantic checker (`check_assignment_expression`) and into the parser's `parse_assignment_expression_recursive`. ## Why / spec simplification Per [13.15.1](https://tc39.es/ecma262/#sec-assignment-operators-static-semantics-early-errors), the only difference between `=` and a compound operator (`+=`, `&&=`, …) is that an object/array literal **destructuring pattern** is allowed *only* with `=`. Every other non-simple left-hand side is already rejected by `AssignmentTarget::cover` (which `fatal_error`s on non-targets). So the check collapses from `operator != Assign && !left.is_simple_assignment_target()` (run after `cover`, needing a fatal-error guard to avoid double-reporting) to a direct check on the LHS expression — a compound operator with an `ObjectExpression`/`ArrayExpression` target — mirroring the existing parenthesized-LHS check right above it: ```rust if operator != AssignmentOperator::Assign && matches!(lhs, Expression::ObjectExpression(_) | Expression::ArrayExpression(_)) { self.error(diagnostics::assignment_is_not_simple(lhs.span())); } ``` No new parser state; no `is_simple_assignment_target` call or `has_fatal_error` guard. ## Conformance No snapshot changes in any suite; parser/semantic/linter tests pass. Verified: `[a] += b` / `{a} += b` → error; `({a} = b)`, `a += b` → clean; `a + b += c` → only the existing `cover` error (no double-report). 🤖 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
Moves the "Invalid left-hand side in assignment" check (a compound assignment operator requires a simple target) out of the semantic checker (
check_assignment_expression) and into the parser'sparse_assignment_expression_recursive.Why / spec simplification
Per 13.15.1, the only difference between
=and a compound operator (+=,&&=, …) is that an object/array literal destructuring pattern is allowed only with=. Every other non-simple left-hand side is already rejected byAssignmentTarget::cover(whichfatal_errors on non-targets).So the check collapses from
operator != Assign && !left.is_simple_assignment_target()(run aftercover, needing a fatal-error guard to avoid double-reporting) to a direct check on the LHS expression — a compound operator with anObjectExpression/ArrayExpressiontarget — mirroring the existing parenthesized-LHS check right above it:No new parser state; no
is_simple_assignment_targetcall orhas_fatal_errorguard.Conformance
No snapshot changes in any suite; parser/semantic/linter tests pass. Verified:
[a] += b/{a} += b→ error;({a} = b),a += b→ clean;a + b += c→ only the existingcovererror (no double-report).🤖 Generated with Claude Code