… reuse stats in mangler builds (#23352)

## What

Fix three allocation problems in the semantic rebuilds performed by the minify/mangle paths, found while auditing the compiler pipeline's scoping rebuilds.

## Details

- **`Semantic::stats` reported `nodes: 0` after node-less builds.** It read `self.nodes.len()`, which is empty when the builder runs in ancestry mode (`with_build_nodes(false)` — the compiler pipeline default). `Semantic` now tracks `node_count` (from `AstNodeStore::node_count`, the source of truth in both modes) and `stats()` returns it. The mangler build inside `Minifier::build` previously received `nodes: 0` and grew the `AstNodes` store from zero capacity by repeated doubling; it now pre-allocates correctly.
- **`Minifier::build` with `compress: None` fed the mangler `Stats::default()`.** All-zero stats are worse than no stats: they skip the `Stats::count` fallback *and* reserve zero capacity for every table. Stats are now threaded as `Option<Stats>` and only passed when the compress phase produced them; the mangle-only path falls back to the counting pass and sizes correctly.
- **`Mangler::build` always re-counted the AST.** Added `Mangler::with_stats`, and `CompilerInterface::mangle` now receives the stats from the initial semantic build, so the mangler's internal semantic rebuild skips its full-AST counting traversal.

Output is unchanged — stats only affect pre-allocation.

## Note

`CompilerInterface::mangle` gains a `stats: Stats` parameter — a breaking change for external implementors that override it (same shape as the `compress` change in #23153).

🤖 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>

… reuse stats in mangler builds (#23352)

Fix three allocation problems in the semantic rebuilds performed by the minify/mangle paths, found while auditing the compiler pipeline's scoping rebuilds.

- **`Semantic::stats` reported `nodes: 0` after node-less builds.** It read `self.nodes.len()`, which is empty when the builder runs in ancestry mode (`with_build_nodes(false)` — the compiler pipeline default). `Semantic` now tracks `node_count` (from `AstNodeStore::node_count`, the source of truth in both modes) and `stats()` returns it. The mangler build inside `Minifier::build` previously received `nodes: 0` and grew the `AstNodes` store from zero capacity by repeated doubling; it now pre-allocates correctly.
- **`Minifier::build` with `compress: None` fed the mangler `Stats::default()`.** All-zero stats are worse than no stats: they skip the `Stats::count` fallback *and* reserve zero capacity for every table. Stats are now threaded as `Option<Stats>` and only passed when the compress phase produced them; the mangle-only path falls back to the counting pass and sizes correctly.
- **`Mangler::build` always re-counted the AST.** Added `Mangler::with_stats`, and `CompilerInterface::mangle` now receives the stats from the initial semantic build, so the mangler's internal semantic rebuild skips its full-AST counting traversal.

Output is unchanged — stats only affect pre-allocation.

`CompilerInterface::mangle` gains a `stats: Stats` parameter — a breaking change for external implementors that override it (same shape as the `compress` change in #23153).

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

## What

Track scoping/AST sync state with a single `scoping_dirty` flag in `Compiler::compile` so each downstream step (inject/define plugins, DCE, compress) only rebuilds semantic when it's actually needed.

## Details

- `InjectGlobalVariables` and `ReplaceGlobalDefines` already return a `changed: bool`; this was previously ignored. It's now OR-ed into `scoping_dirty`.
- `scoping_dirty` starts `true` only when the transformer runs — the parser, React Compiler (rebuilds scoping on success, returns the untouched scoping on bail-out), and any fresh `SemanticBuilder` all leave scoping in sync.
- The pre-plugin rebuild is now gated on `scoping_dirty`, skipping a needless rebuild when no transform ran.
- DCE and Compress are now a single mutually-exclusive `if/else`, both rebuilding semantic only when `scoping_dirty`.
- `Compressor::build` (which always rebuilds semantic internally) is replaced with `build_with_scoping`, so when scoping is already in sync the compressor skips its own `SemanticBuilder` pass.
- The three rebuild sites are extracted into a `rebuild_scoping` helper, which enables enum eval when a transform is configured so const-enum resolution matches the original semantic build.

## Note

The `CompilerInterface::compress` trait method gains a `scoping: Scoping` parameter — a breaking change for external implementors that override it.

### 💥 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>

… reuse stats in mangler builds (#23352)

Fix three allocation problems in the semantic rebuilds performed by the minify/mangle paths, found while auditing the compiler pipeline's scoping rebuilds.

- **`Semantic::stats` reported `nodes: 0` after node-less builds.** It read `self.nodes.len()`, which is empty when the builder runs in ancestry mode (`with_build_nodes(false)` — the compiler pipeline default). `Semantic` now tracks `node_count` (from `AstNodeStore::node_count`, the source of truth in both modes) and `stats()` returns it. The mangler build inside `Minifier::build` previously received `nodes: 0` and grew the `AstNodes` store from zero capacity by repeated doubling; it now pre-allocates correctly.
- **`Minifier::build` with `compress: None` fed the mangler `Stats::default()`.** All-zero stats are worse than no stats: they skip the `Stats::count` fallback *and* reserve zero capacity for every table. Stats are now threaded as `Option<Stats>` and only passed when the compress phase produced them; the mangle-only path falls back to the counting pass and sizes correctly.
- **`Mangler::build` always re-counted the AST.** Added `Mangler::with_stats`, and `CompilerInterface::mangle` now receives the stats from the initial semantic build, so the mangler's internal semantic rebuild skips its full-AST counting traversal.

Output is unchanged — stats only affect pre-allocation.

`CompilerInterface::mangle` gains a `stats: Stats` parameter — a breaking change for external implementors that override it (same shape as the `compress` change in #23153).

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