…paired inference (#21516)

## Summary

A public (or protected) getter paired with a `private set(v: T)` should get its return type from the setter's parameter annotation — that's the standard `isolatedDeclarations` accessor-pair inference rule ("one annotated side is enough"). Previously, `collect_accessor_annotations` skipped any accessor with a `private` modifier, so the pairing never happened and `TS9009` fired on the untyped getter.

This change:

- No longer skips `private`-modifier accessors when collecting annotations for paired inference.
- For private **setters**, collects the explicit parameter type annotation — same behavior as before for non-private setters (no body inference).
- For private **getters**, only uses an explicit return type annotation. Running body inference would surface errors like `TS9038` on the private accessor's body, which is irrelevant because the private accessor is emitted as a type-erased class member anyway.

## Example

```ts
export class MockProxy {
  get isRunning() {
    return this._state.isRunning;
  }

  private set isRunning(val: boolean) {
    this._state.isRunning = val;
  }
}
```

Before: `TS9009: At least one accessor must have an explicit return type annotation`.
After: no error — emits `get isRunning(): boolean;` and `private set isRunning(value);`, matching tsc.

## Test plan

- [x] Added fixtures for both a public getter + private setter pair and a protected getter + private setter pair
- [x] `cargo test -p oxc_isolated_declarations` — no regression on existing private-accessor snapshots

Closes #21503 (case 2)

…paired inference (#21516)

## Summary

A public (or protected) getter paired with a `private set(v: T)` should get its return type from the setter's parameter annotation — that's the standard `isolatedDeclarations` accessor-pair inference rule ("one annotated side is enough"). Previously, `collect_accessor_annotations` skipped any accessor with a `private` modifier, so the pairing never happened and `TS9009` fired on the untyped getter.

This change:

- No longer skips `private`-modifier accessors when collecting annotations for paired inference.
- For private **setters**, collects the explicit parameter type annotation — same behavior as before for non-private setters (no body inference).
- For private **getters**, only uses an explicit return type annotation. Running body inference would surface errors like `TS9038` on the private accessor's body, which is irrelevant because the private accessor is emitted as a type-erased class member anyway.

## Example

```ts
export class MockProxy {
  get isRunning() {
    return this._state.isRunning;
  }

  private set isRunning(val: boolean) {
    this._state.isRunning = val;
  }
}
```

Before: `TS9009: At least one accessor must have an explicit return type annotation`.
After: no error — emits `get isRunning(): boolean;` and `private set isRunning(value);`, matching tsc.

## Test plan

- [x] Added fixtures for both a public getter + private setter pair and a protected getter + private setter pair
- [x] `cargo test -p oxc_isolated_declarations` — no regression on existing private-accessor snapshots

Closes #21503 (case 2)

…paired inference (#21516)

## Summary

A public (or protected) getter paired with a `private set(v: T)` should get its return type from the setter's parameter annotation — that's the standard `isolatedDeclarations` accessor-pair inference rule ("one annotated side is enough"). Previously, `collect_accessor_annotations` skipped any accessor with a `private` modifier, so the pairing never happened and `TS9009` fired on the untyped getter.

This change:

- No longer skips `private`-modifier accessors when collecting annotations for paired inference.
- For private **setters**, collects the explicit parameter type annotation — same behavior as before for non-private setters (no body inference).
- For private **getters**, only uses an explicit return type annotation. Running body inference would surface errors like `TS9038` on the private accessor's body, which is irrelevant because the private accessor is emitted as a type-erased class member anyway.

## Example

```ts
export class MockProxy {
  get isRunning() {
    return this._state.isRunning;
  }

  private set isRunning(val: boolean) {
    this._state.isRunning = val;
  }
}
```

Before: `TS9009: At least one accessor must have an explicit return type annotation`.
After: no error — emits `get isRunning(): boolean;` and `private set isRunning(value);`, matching tsc.

## Test plan

- [x] Added fixtures for both a public getter + private setter pair and a protected getter + private setter pair
- [x] `cargo test -p oxc_isolated_declarations` — no regression on existing private-accessor snapshots

Closes #21503 (case 2)

…paired inference (#21516)

## Summary

A public (or protected) getter paired with a `private set(v: T)` should get its return type from the setter's parameter annotation — that's the standard `isolatedDeclarations` accessor-pair inference rule ("one annotated side is enough"). Previously, `collect_accessor_annotations` skipped any accessor with a `private` modifier, so the pairing never happened and `TS9009` fired on the untyped getter.

This change:

- No longer skips `private`-modifier accessors when collecting annotations for paired inference.
- For private **setters**, collects the explicit parameter type annotation — same behavior as before for non-private setters (no body inference).
- For private **getters**, only uses an explicit return type annotation. Running body inference would surface errors like `TS9038` on the private accessor's body, which is irrelevant because the private accessor is emitted as a type-erased class member anyway.

## Example

```ts
export class MockProxy {
  get isRunning() {
    return this._state.isRunning;
  }

  private set isRunning(val: boolean) {
    this._state.isRunning = val;
  }
}
```

Before: `TS9009: At least one accessor must have an explicit return type annotation`.
After: no error — emits `get isRunning(): boolean;` and `private set isRunning(value);`, matching tsc.

## Test plan

- [x] Added fixtures for both a public getter + private setter pair and a protected getter + private setter pair
- [x] `cargo test -p oxc_isolated_declarations` — no regression on existing private-accessor snapshots

Closes #21503 (case 2)

### 🐛 Bug Fixes

- 48967e8 isolated_declarations: Drop required type check for private
parameter properties on private constructors (#21515) (Dunqing)
- 91e5bde transformer/typescript: Preserve computed-key static block
when class has an empty constructor (#21562) (Dunqing)
- 50e9d26 mangler: Assign correct slot to shadowed function-expression
names (#21535) (Dunqing)
- 065ce47 isolated_declarations: Collect types from private accessors
for paired inference (#21516) (Dunqing)
- 00fc136 codegen: Preserve coverage comments before object properties
(#21312) (bab)
- d676e0c minifier: Mark LHS of `??=` as read when converting from `==
null &&` (#21546) (Gunnlaugur Thor Briem)

### ⚡ Performance

- e45efc5 parser: Reduce `try_parse` usage in favour of `lookahead`
(#21532) (Boshen)
- ddb1bf8 parser: Avoid redundant `IdentifierReference` clone in
shorthand property (#21511) (Boshen)
- be2b392 allocator: Store pointers directly in `Arena` (#21483)
(overlookmotel)

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