### 💥 BREAKING CHANGES

- 7a76cd3 estree: [**BREAKING**] Make whether to include TS fields a
runtime option (#23574) (overlookmotel)
- e7b6b68 estree: [**BREAKING**] `ESTree` config use methods not consts
(#23573) (overlookmotel)

### 🚀 Features

- 556cc6d data_structures: Add `CodeBuffer::as_str` method (#23571)
(overlookmotel)
- 38c4b06 parser: Add friendly error for adjacent JSX elements (#23378)
(sapphi-red)
- 53509a8 minifier: Treeshake pure typed arrays and Set/Map array
literals (#23469) (Dunqing)
- 09762d9 minifier: Inline const value for read-only vars (#22593)
(Dunqing)

### 🐛 Bug Fixes

- 20375f9 react_compiler: Keep imports referenced only by a computed key
(#23586) (Boshen)
- 31bfd9b minifier: Keep Object introspection calls on a possible Proxy
(#23483) (Dunqing)
- 837a395 parser: Treat a line comment after ':' as leading, not
trailing (#23515) (Dunqing)
- e409fe0 minifier: Keep `new Map`/`WeakSet`/`WeakMap` with a string
argument (#23470) (Dunqing)
- ae02b4e ci/parser: Use `minimal` for vitest reporter (#23457)
(camc314)

### ⚡ Performance

- cf24329 mangler: Compile slot sort once instead of per CAPACITY
(#23577) (Boshen)
- 4058a6a parser: Reduce code bloat from verify_modifiers
monomorphization (#23576) (Boshen)
- 053b0c1 estree: Remove pointless `mem::take` (#23572) (overlookmotel)
- dfb52b6 transformer: Pre-size statement vecs in TS enum & namespace
lowering (#23516) (Yunfei He)
- 970e09a minifier: Compute template-literal inline checks in a single
pass (#23467) (Yunfei He)
- 3170c0e semantic,mangler,minifier: Fix `Semantic::stats` node count
and reuse stats in mangler builds (#23352) (Boshen)
- d1fa6e0 minifier: Evaluate ternary branches once in
minimize_conditional_expression (#23479) (Yunfei He)
- 3fa8051 transformer: Pre-size JSX props vec to attribute count
(#23466) (Yunfei He)
- 488b382 react_compiler: Borrow binding names in prefilter instead of
allocating (#23471) (Yunfei He)
- bcb3894 minifier: Incremental scoping refresh, delete
LiveUsageCollector (#23197) (Dunqing)

### 📚 Documentation

- f68641e data_structures: Improve docs on safety contract (#23575)
(overlookmotel)

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

…ss (#23467)

## Measured allocation reduction

The change reduces allocations on the minifier hot path — deterministic,
every delta a reduction (no
increases), captured in `allocs_minifier.snap` (updated in this PR):

| file | sys allocs: before → after | arena allocs: before → after |
| --- | --- | --- |
| kitchen-sink.tsx | 2640 → 2638 (**−2**) | 90554 → 90549 (**−5**) |
| App.tsx | 115 → 113 (**−2**) | 17012 → 17010 (**−2**) |
| pdf.mjs | 2614 → 2613 (**−1**) | — |
| antd.js | — | 337233 → 337232 (**−1**) |

(Small in absolute terms, but a clean deterministic reduction with zero
regressions across every file.)

## What & why

`inline_template_literal` ran its `may_have_side_effects` +
`to_js_string` checks **twice** per
expression — once in an `.any()` pre-scan, then again in the drain loop
that partitioned the
expressions. This collapses them into a **single pass**, so per
expression the checks go from ≈2 to
exactly 1 (never more in any case), and the rebuild is sized exactly:

```rust
let mut inline_exprs = Vec::new();
for (idx, expr) in t.expressions.iter().enumerate() {
    if !expr.may_have_side_effects(ctx) && let Some(str) = expr.to_js_string(ctx) {
        inline_exprs.push((idx, str));
    }
}
if inline_exprs.is_empty() { return; }
let mut kept = ctx.ast.vec_with_capacity(t.expressions.len() - inline_exprs.len());
let mut inline_idxs = inline_exprs.iter().map(|(idx, _)| *idx).peekable();
for (idx, expr) in t.expressions.drain(..).enumerate() {
    if inline_idxs.peek() == Some(&idx) { inline_idxs.next(); ctx.drop_expression(&expr); }
    else { kept.push(expr); }
}
t.expressions = kept;
```

`to_js_string` recurses over the expression and can allocate, so
removing the duplicate calls is real
work. `inline_exprs` also moves from `Vec::with_capacity(len)` (#20389)
to a lazy `Vec::new()` (no
allocation on the common no-inline path), and `kept` is sized exactly
(`len - inline_exprs.len()`) —
which is what produces the allocation reduction above.

## Behavior-preserving

Computing all `to_js_string` values before any `drop_expression` is
safe: `drop_expression` only sets
dirty/mutation bookkeeping, disjoint from the immutable scoping/symbol
state the checks read. Indices
are collected ascending, so the index-matched rebuild reproduces the
exact same kept / dropped /
inlined partition. `cargo test -p oxc_minifier` (535 tests) passes with
no snapshot drift.

CodSpeed will arbitrate the instruction-count effect of the
de-duplicated checks (constant template
interpolations that trigger inlining are uncommon in real code, so that
delta may be small); the
allocation reduction above is the deterministic part.

---

Prepared with AI assistance.

### 💥 BREAKING CHANGES

- 7a76cd3 estree: [**BREAKING**] Make whether to include TS fields a
runtime option (#23574) (overlookmotel)
- e7b6b68 estree: [**BREAKING**] `ESTree` config use methods not consts
(#23573) (overlookmotel)

### 🚀 Features

- 556cc6d data_structures: Add `CodeBuffer::as_str` method (#23571)
(overlookmotel)
- 38c4b06 parser: Add friendly error for adjacent JSX elements (#23378)
(sapphi-red)
- 53509a8 minifier: Treeshake pure typed arrays and Set/Map array
literals (#23469) (Dunqing)
- 09762d9 minifier: Inline const value for read-only vars (#22593)
(Dunqing)

### 🐛 Bug Fixes

- 20375f9 react_compiler: Keep imports referenced only by a computed key
(#23586) (Boshen)
- 31bfd9b minifier: Keep Object introspection calls on a possible Proxy
(#23483) (Dunqing)
- 837a395 parser: Treat a line comment after ':' as leading, not
trailing (#23515) (Dunqing)
- e409fe0 minifier: Keep `new Map`/`WeakSet`/`WeakMap` with a string
argument (#23470) (Dunqing)
- ae02b4e ci/parser: Use `minimal` for vitest reporter (#23457)
(camc314)

### ⚡ Performance

- cf24329 mangler: Compile slot sort once instead of per CAPACITY
(#23577) (Boshen)
- 4058a6a parser: Reduce code bloat from verify_modifiers
monomorphization (#23576) (Boshen)
- 053b0c1 estree: Remove pointless `mem::take` (#23572) (overlookmotel)
- dfb52b6 transformer: Pre-size statement vecs in TS enum & namespace
lowering (#23516) (Yunfei He)
- 970e09a minifier: Compute template-literal inline checks in a single
pass (#23467) (Yunfei He)
- 3170c0e semantic,mangler,minifier: Fix `Semantic::stats` node count
and reuse stats in mangler builds (#23352) (Boshen)
- d1fa6e0 minifier: Evaluate ternary branches once in
minimize_conditional_expression (#23479) (Yunfei He)
- 3fa8051 transformer: Pre-size JSX props vec to attribute count
(#23466) (Yunfei He)
- 488b382 react_compiler: Borrow binding names in prefilter instead of
allocating (#23471) (Yunfei He)
- bcb3894 minifier: Incremental scoping refresh, delete
LiveUsageCollector (#23197) (Dunqing)

### 📚 Documentation

- f68641e data_structures: Improve docs on safety contract (#23575)
(overlookmotel)

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