`parse_unary_expression_or_higher` called `is_update_expression()` — a `match` on `cur_kind()` — and then, when it returned false, re-`match`ed the same token inside `parse_simple_unary_expression`. On the prefix-unary / `await` / non-JSX-`<` paths that is two matches on the same token, once per operand.

Fold both into one `match` directly in `parse_unary_expression_or_higher`: prefix unary operator, `await`, and a non-JSX `<` (TS type assertion / JSX-in-non-JSX error) are handled explicitly; everything else is an `UpdateExpression` (possibly with postfix `++`/`--`). This is exactly the union of the old `is_update_expression` routing and `parse_simple_unary_expression`, so `is_update_expression` is removed.

`parse_simple_unary_expression` is untouched (still used by `parse_unary_expression` for nested operands and by the TS statement parser).

Behavior-preserving:
- `cargo coverage -- parser` — Test262 / Babel / TypeScript / ESTree snapshots byte-identical (no `.snap` changes).
- `just allocs` — allocation snapshot unchanged.
- Full parser output byte-identical to baseline on unary / `await` / TS type-assertion / JSX fixtures across `.js`, `.ts`, and `.tsx` (covers the `<`-by-source-type branches).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

`parse_unary_expression_or_higher` called `is_update_expression()` — a `match` on `cur_kind()` — and then, when it returned false, re-`match`ed the same token inside `parse_simple_unary_expression`. On the prefix-unary / `await` / non-JSX-`<` paths that is two matches on the same token, once per operand.

Fold both into one `match` directly in `parse_unary_expression_or_higher`: prefix unary operator, `await`, and a non-JSX `<` (TS type assertion / JSX-in-non-JSX error) are handled explicitly; everything else is an `UpdateExpression` (possibly with postfix `++`/`--`). This is exactly the union of the old `is_update_expression` routing and `parse_simple_unary_expression`, so `is_update_expression` is removed.

`parse_simple_unary_expression` is untouched (still used by `parse_unary_expression` for nested operands and by the TS statement parser).

Behavior-preserving:
- `cargo coverage -- parser` — Test262 / Babel / TypeScript / ESTree snapshots byte-identical (no `.snap` changes).
- `just allocs` — allocation snapshot unchanged.
- Full parser output byte-identical to baseline on unary / `await` / TS type-assertion / JSX fixtures across `.js`, `.ts`, and `.tsx` (covers the `<`-by-source-type branches).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

### 💥 BREAKING CHANGES

- 7a24911 codegen: [**BREAKING**] Borrow sourcemaps from codegen
(#23422) (Boshen)
- bb0ed44 transformer: [**BREAKING**] Disable styled-components
transpileTemplateLiterals by default (#23171) (Boshen)

### 🚀 Features

- 1490a0a linter/react: Implement react-compiler rule (#23202) (Boshen)
- 6c0bdf0 transformer/react-refresh: Support `module.property.useHook()`
(#23190) (Dunqing)
- 47991bd semantic: Report TS1228 for invalid type predicates (#23174)
(camc314)
- 1d3af58 parser: Add TS2398 parameter property diagnostic (#23216)
(camc314)
- 44313da semantic: Add `scope_is_descendant_of` api (#22313) (camc314)
- e5050c0 parser: Improve diagnostic for rest initializer (#23205)
(camc314)
- ec266bb transformer: Run React Compiler as a feature-gated transform
pass (#23201) (Boshen)
- e7374fe parser: Report error for `const` modifier on interface type
parameter (#23173) (camc314)
- a7c1c9b parser: Report ambient definite variable assertions (#23165)
(camc314)
- d169fcd parser: Report invalid class definite assertions (#23164)
(camc314)
- 00244d8 parser: Report definite property initializer errors (#23160)
(camc314)

### 🐛 Bug Fixes

- 52d0c31 transformer: Replace ambient dot defines (#23231) (camc314)
- 2c28748 transformer/class: Parent generated constructors to class
scope (#23222) (camc314)
- 8edd234 parser: Report accessor definite assertion on token (#23203)
(camc314)
- de38a3f react_compiler: Keep imports referenced only by a local
re-export (#23176) (Boshen)
- f5721c2 codegen: Preserve parentheses around `intrinsic` type
reference (#23156) (Boshen)
- e89f81d parser: Don't emit TS1477 for parenthesized instantiation
expression (#23147) (Boshen)
- 8a04149 parser: Reject module-referencing imports/exports in a
namespace body (#22829) (Boshen)

### ⚡ Performance

- 2783295 parser: Table-driven operator precedence lookup (#23346)
(Boshen)
- 231d5de parser: Single-match member expression dispatch (#23347)
(Boshen)
- e89729b codegen: Accept one-shot wrap closures (#23265) (camc314)
- a6c11fa parser: Force-inline read_non_decimal to fold per-digit number
dispatch (#23157) (Boshen)
- d74964c parser: Store class definite assertion offset (#23170)
(camc314)
- f0fda4d parser: Shrink-wrap cold diagnostic tails out of hot frames
(#23159) (Boshen)
- a082180 parser: Store definite assertion offset (#23167) (camc314)
- 534f9c6 oxc: Conditionally rebuild semantic in compiler pipeline
(#23153) (Boshen)
- b435c6a parser: Skip checkpoint for `infer T extends U` constraint in
disallow context (#23128) (Boshen)
- 7464dce parser: Peek instead of checkpoint/rewind for `export default`
modifier (#23124) (Boshen)
- 80a9a32 parser: Fast-path single-keyword TS declarations (#23083)
(Boshen)
- da1a6c6 diagnostics: Migrate to allocation-optimized oxc-miette
(#23094) (Boshen)
- b7b08ce parser: Peek once for the static modifier disambiguation
(#23079) (Boshen)
- e7e07a3 parser: Fold unary dispatch into a single match (#23076)
(Boshen)

### 📚 Documentation

- d241add semantic: Add `AGENTS.md` test guidance for agents (#23441)
(camc314)
- 026f1ae parser: Add `AGENTS.md` test guidance for agents (#23440)
(camc314)
- 09755ac transformer: Add `AGENTS.md` test guidance for agents (#23439)
(camc314)
- e6bdfd4 lexer: Correct reference link for `byte_handlers!` (#23313)
(Dunqing)
- 65b6d7a allocator: Fix memory leaks in `Arena` examples (#23257)
(overlookmotel)

Co-authored-by: Boshen <1430279+Boshen@users.noreply.github.com>

`parse_unary_expression_or_higher` called `is_update_expression()` — a `match` on `cur_kind()` — and then, when it returned false, re-`match`ed the same token inside `parse_simple_unary_expression`. On the prefix-unary / `await` / non-JSX-`<` paths that is two matches on the same token, once per operand.

Fold both into one `match` directly in `parse_unary_expression_or_higher`: prefix unary operator, `await`, and a non-JSX `<` (TS type assertion / JSX-in-non-JSX error) are handled explicitly; everything else is an `UpdateExpression` (possibly with postfix `++`/`--`). This is exactly the union of the old `is_update_expression` routing and `parse_simple_unary_expression`, so `is_update_expression` is removed.

`parse_simple_unary_expression` is untouched (still used by `parse_unary_expression` for nested operands and by the TS statement parser).

Behavior-preserving:
- `cargo coverage -- parser` — Test262 / Babel / TypeScript / ESTree snapshots byte-identical (no `.snap` changes).
- `just allocs` — allocation snapshot unchanged.
- Full parser output byte-identical to baseline on unary / `await` / TS type-assertion / JSX fixtures across `.js`, `.ts`, and `.tsx` (covers the `<`-by-source-type branches).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

### 💥 BREAKING CHANGES

- 7a24911 codegen: [**BREAKING**] Borrow sourcemaps from codegen
(#23422) (Boshen)
- bb0ed44 transformer: [**BREAKING**] Disable styled-components
transpileTemplateLiterals by default (#23171) (Boshen)

### 🚀 Features

- 1490a0a linter/react: Implement react-compiler rule (#23202) (Boshen)
- 6c0bdf0 transformer/react-refresh: Support `module.property.useHook()`
(#23190) (Dunqing)
- 47991bd semantic: Report TS1228 for invalid type predicates (#23174)
(camc314)
- 1d3af58 parser: Add TS2398 parameter property diagnostic (#23216)
(camc314)
- 44313da semantic: Add `scope_is_descendant_of` api (#22313) (camc314)
- e5050c0 parser: Improve diagnostic for rest initializer (#23205)
(camc314)
- ec266bb transformer: Run React Compiler as a feature-gated transform
pass (#23201) (Boshen)
- e7374fe parser: Report error for `const` modifier on interface type
parameter (#23173) (camc314)
- a7c1c9b parser: Report ambient definite variable assertions (#23165)
(camc314)
- d169fcd parser: Report invalid class definite assertions (#23164)
(camc314)
- 00244d8 parser: Report definite property initializer errors (#23160)
(camc314)

### 🐛 Bug Fixes

- 52d0c31 transformer: Replace ambient dot defines (#23231) (camc314)
- 2c28748 transformer/class: Parent generated constructors to class
scope (#23222) (camc314)
- 8edd234 parser: Report accessor definite assertion on token (#23203)
(camc314)
- de38a3f react_compiler: Keep imports referenced only by a local
re-export (#23176) (Boshen)
- f5721c2 codegen: Preserve parentheses around `intrinsic` type
reference (#23156) (Boshen)
- e89f81d parser: Don't emit TS1477 for parenthesized instantiation
expression (#23147) (Boshen)
- 8a04149 parser: Reject module-referencing imports/exports in a
namespace body (#22829) (Boshen)

### ⚡ Performance

- 2783295 parser: Table-driven operator precedence lookup (#23346)
(Boshen)
- 231d5de parser: Single-match member expression dispatch (#23347)
(Boshen)
- e89729b codegen: Accept one-shot wrap closures (#23265) (camc314)
- a6c11fa parser: Force-inline read_non_decimal to fold per-digit number
dispatch (#23157) (Boshen)
- d74964c parser: Store class definite assertion offset (#23170)
(camc314)
- f0fda4d parser: Shrink-wrap cold diagnostic tails out of hot frames
(#23159) (Boshen)
- a082180 parser: Store definite assertion offset (#23167) (camc314)
- 534f9c6 oxc: Conditionally rebuild semantic in compiler pipeline
(#23153) (Boshen)
- b435c6a parser: Skip checkpoint for `infer T extends U` constraint in
disallow context (#23128) (Boshen)
- 7464dce parser: Peek instead of checkpoint/rewind for `export default`
modifier (#23124) (Boshen)
- 80a9a32 parser: Fast-path single-keyword TS declarations (#23083)
(Boshen)
- da1a6c6 diagnostics: Migrate to allocation-optimized oxc-miette
(#23094) (Boshen)
- b7b08ce parser: Peek once for the static modifier disambiguation
(#23079) (Boshen)
- e7e07a3 parser: Fold unary dispatch into a single match (#23076)
(Boshen)

### 📚 Documentation

- d241add semantic: Add `AGENTS.md` test guidance for agents (#23441)
(camc314)
- 026f1ae parser: Add `AGENTS.md` test guidance for agents (#23440)
(camc314)
- 09755ac transformer: Add `AGENTS.md` test guidance for agents (#23439)
(camc314)
- e6bdfd4 lexer: Correct reference link for `byte_handlers!` (#23313)
(Dunqing)
- 65b6d7a allocator: Fix memory leaks in `Arena` examples (#23257)
(overlookmotel)

Co-authored-by: Boshen <1430279+Boshen@users.noreply.github.com>