[js_interop_gen] Require code_builder: ^4.12.0 and update golden headers - #576

Stacked on dart-lang#576.

Remove 13 unreferenced declarations identified by `pkg:undead`
(`--extra-roots=lib/src/dart_main.dart`):
- `createSourceFile` in `lib/src/js/typescript.dart`
- `InterfacelikeExtension` in `lib/src/js/webidl_api.dart`
- 11 unused TypeScript AST extension types in
  `lib/src/js/typescript.types.dart` (`TSTypePredicateNode`,
  `TSNamedTupleMember`, `TSFunctionTypeNode`, `TSConstructorTypeNode`,
  `TSPropertyAccessExpression`, `TSNamespaceExport`, `TSExportAssignment`,
  `TSClassDeclaration`, `TSInterfaceDeclaration`, `TSPropertyDeclaration`,
  `TSMethodDeclaration`)

…ransformer (#580)

* [js_interop_gen] Require `code_builder: ^4.12.0` and update golden headers

`package:code_builder` `4.12.0` fixed dart-lang/tools#2404
by emitting scoped lint ignores (`no_leading_underscores_for_library_prefixes`)
directly in the sorted top-of-file `// ignore_for_file:` block before library
annotations and directives.

- Bump `code_builder` dependency constraint to `^4.12.0` (compatible with
  `sdk: ^3.10.0`, preserving `js_interop_gen`'s `sdk: ^3.12.0` constraint).
- Remove the now-obsolete `replaceFirstMapped` regex workaround for
  `dart-lang/tools#2404` in `lib/src/interop_gen/transform.dart`.
- Regenerate the expected test golden headers across `test/`.

* [js_interop_gen] Remove unused JS interop extension types and bindings

Stacked on #576.

Remove 13 unreferenced declarations identified by `pkg:undead`
(`--extra-roots=lib/src/dart_main.dart`):
- `createSourceFile` in `lib/src/js/typescript.dart`
- `InterfacelikeExtension` in `lib/src/js/webidl_api.dart`
- 11 unused TypeScript AST extension types in
  `lib/src/js/typescript.types.dart` (`TSTypePredicateNode`,
  `TSNamedTupleMember`, `TSFunctionTypeNode`, `TSConstructorTypeNode`,
  `TSPropertyAccessExpression`, `TSNamespaceExport`, `TSExportAssignment`,
  `TSClassDeclaration`, `TSInterfaceDeclaration`, `TSPropertyDeclaration`,
  `TSMethodDeclaration`)

* [js_interop_gen] Deduplicate `UnionType` and `IntersectionType` via `UnionOrIntersectionType`

Stacked on #577.

- Extract `sealed class UnionOrIntersectionType extends DeclarationType` in
  `lib/src/ast/types.dart` (mirroring `_UnionOrIntersectionDeclaration`) to
  share `types`, `isNullable`, `declarationName`, `id`, `emit()`, `hashCode`,
  and `operator ==` across `UnionType` and `IntersectionType` (`pkg:dedupe`
  `cluster-47`).
- Fix `UnionType.==` and `IntersectionType.==`, which previously checked
  `other is TupleType` due to copy-paste.
- Consolidate `UnionType` / `IntersectionType` pattern cases in
  `lib/src/ast/helpers.dart` and
  `lib/src/interop_gen/transform/dependency_walker.dart`.
- Write `dart_main.js` via an atomic temporary file rename in
  `compileDartMain()` (`lib/src/cli.dart`) so parallel `dart test` isolates in
  the same VM process cannot truncate `dart_main.js` while `node main.mjs` is
  loading it.

* [js_interop_gen] Decompose `Transformer._transformType` and deduplicate type caching

Stacked on #578.

- Extract `_transformConditionalType`, `_transformTypeLiteral`,
  `_transformClosureType`, `_transformUnionType`,
  `_transformIntersectionType`, and `_transformIndexedAccessType` from
  `Transformer._transformType` in
  `lib/src/interop_gen/transform/transformer.dart`, reducing
  `Transformer._transformType` cognitive complexity from `190` to `59` (-68.9%).
- Extract `_filterNonNullableTypeNodes` and `_getOrCreateCachedType` helpers on
  `Transformer`, eliminating duplicate union/intersection filtering and
  `typeMap` caching blocks (`pkg:dedupe` `cluster-45`, `cluster-51`, and
  `cluster-52`).

* Enforce symmetric equality and length check in UnionOrIntersectionType.==

* [js_interop_gen] Split union/intersection AST types and extract TypeTransformer

* chore(js_interop_gen): restore original inline comments in extracted type helpers

* chore(js_interop_gen): revert unrelated formatting change in translator.dart

* fix(js_interop_gen): update js_type_supertypes for Dart 3.12 and prefer JSObject over JSIterable

* fix(js_interop_gen): write compileDartMain output atomically

* refactor(js_interop_gen): use firstWhere in computeJsTypeSupertypes

Revisions updated by `dart tools/rev_sdk_deps.dart`.

native (https://github.com/dart-lang/native/compare/f628b26..27f7678):
  27f767827  Mon Sep 28 14:51:28 2026 +0200  Daco Harkes  [hooks_runner] Remove `KernelAssets` and `Target` (dart-lang/native#3703)
  ddc7d6deb  Mon Sep 28 05:40:03 2026 +0200  Jakob Kordež  [ffigen] Skip typedefs to function pointers with unsupported parameter types (dart-lang/native#3694)
  177d283d9  Mon Sep 28 04:30:28 2026 +0200  Jakob Kordež  [ffigen] Generate bindings for C++ enums, structs and unions nested in namespaces and records (dart-lang/native#3644)
  5ee8f67d8  Mon Sep 28 11:39:14 2026 +1000  Liam Appelbe  [objective_c] Clarify block isolate scoping (dart-lang/native#3692)
  25f090116  Fri Sep 25 12:09:12 2026 +1000  Liam Appelbe  [ffigen][jnigen] Deprecate YAML config (dart-lang/native#3654)
  8364413eb  Fri Sep 25 10:09:50 2026 +1000  Liam Appelbe  [jnigen] Document nullability (dart-lang/native#3690)
  e8d518574  Thu Sep 24 18:02:46 2026 +1000  Liam Appelbe  [ffigen] Code snippet-ify ffigen and objective_c (dart-lang/native#3685)
  663385955  Thu Sep 24 03:21:53 2026 +0300  Manar Elhabbal  [ffigen] prevent setting both cpp and objectiveC in ffigenerator (dart-lang/native#3687)
  1cf40952a  Thu Sep 24 09:27:09 2026 +1000  Liam Appelbe  [objective_c] Remove arm64e build hack (dart-lang/native#3680)
  c44550b6e  Wed Sep 23 13:01:33 2026 +0200  Simon Binder  [web_assets] Scaffold package (dart-lang/native#3610)
  57b4bad69  Wed Sep 23 16:21:27 2026 +1000  Liam Appelbe  [swift2objc] Code snippet-ify swift2objc (dart-lang/native#3684)
  5cee1d0be  Wed Sep 23 10:16:29 2026 +0530  Rachit Vikram Singh  [ffigen] Add Input.appendCompilerOptions to append clang args to defaults (`#3630`) (dart-lang/native#3676)
  225a648df  Wed Sep 23 14:37:13 2026 +1000  Liam Appelbe  [jnigen] Code snippet-ify jnigen and co (dart-lang/native#3641)
  2030decf9  Wed Sep 23 13:51:24 2026 +1000  Liam Appelbe  [infra] Move snippets_tool to its own package (dart-lang/native#3683)
  6fa2beea2  Wed Sep 23 12:14:28 2026 +1000  Liam Appelbe  [objective_c] Revert `#3664` (dart-lang/native#3681)
  ed7605f8a  Tue Sep 22 12:03:22 2026 +0530  Sivapriya  [jni] Add deep conversion utils (dart-lang/native#3635)
  8574b7422  Tue Sep 22 08:31:11 2026 +0200  Lukas Klingsbo  [ffigen] Allow package:cli_util 0.5.x and 0.6.x (dart-lang/native#3673)

test (https://github.com/dart-lang/test/compare/9946c95..4f92d53):
  4f92d530  Fri Sep 25 16:46:22 2026 -0700  Nate Bosch  Unskip a test on windows (dart-lang/test#2772)
  7fb84866  Fri Sep 25 14:52:39 2026 -0700  Nate Bosch  Bundle skips at the end of the GitHub reporter (dart-lang/test#2768)
  603e5ec5  Thu Sep 24 14:00:41 2026 -0700  Nate Bosch  Clean up the runner's temporary directories (dart-lang/test#2763)
  4bf04d90  Thu Sep 24 12:41:15 2026 -0700  Nate Bosch  Refactor signal handling in executable.dart (dart-lang/test#2765)
  2c660a84  Tue Sep 22 15:33:34 2026 -0700  Nate Bosch  Regenerate mono_repo output (dart-lang/test#2767)

tools (https://github.com/dart-lang/tools/compare/3614ce0..d87eaf7):
  d87eaf79  Thu Sep 24 08:31:33 2026 -0700  Kevin Moore  fix(benchmark_harness): migrate subprocess spawning to package:cli_util (dart-lang/tools#2585)
  8ccf8ccf  Wed Sep 23 05:09:10 2026 +0530  Aman Maurya  [string_scanner] Extract a mixin for LineScanner and deduplicate eager scanning logic (dart-lang/tools#2569)
  afcdd6d9  Tue Sep 22 15:38:07 2026 +0200  Morgan :)  Document that watch events converge on filesystem state. (dart-lang/tools#2607)
  f2157cbc  Tue Sep 22 04:52:58 2026 +0300  Hasan Armoush  [code_builder] Add null-aware cascades, cascade index, and fluent cascade helpers (dart-lang/tools#2540)

web (https://github.com/dart-lang/web/compare/e5c6c02..ec71a4c):
  ec71a4c  Mon Sep 28 10:07:01 2026 -0700  Kevin Moore  [js_interop_gen] Require `code_builder: ^4.12.0` and update golden headers (dart-lang/web#576)

[email protected]

Change-Id: I766bc5b2b1297e3251990821bb73387ba685e39b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/556320
Commit-Queue: Nate Bosch <[email protected]>
Reviewed-by: Brian Quinlan <[email protected]>