Stop using transitive digest files for resolvers. (#3897)

_test/test/goldens/generated_build_script.dart

@@ -8,10 +8,9 @@ import 'package:build_test/builder.dart' as _i4;
 import 'package:build_config/build_config.dart' as _i5;
 import 'package:build_modules/builders.dart' as _i6;
 import 'package:build/build.dart' as _i7;
-import 'package:build_resolvers/builder.dart' as _i8;
-import 'dart:isolate' as _i9;
-import 'package:build_runner/build_runner.dart' as _i10;
-import 'dart:io' as _i11;
+import 'dart:isolate' as _i8;
+import 'package:build_runner/build_runner.dart' as _i9;
+import 'dart:io' as _i10;
 
 final _builders = <_i1.BuilderApplication>[
   _i1.apply(
@@ -145,18 +144,6 @@ final _builders = <_i1.BuilderApplication>[
         const _i7.BuilderOptions(<String, dynamic>{r'compiler': r'dart2js'}),
     appliesBuilders: const [r'build_web_compilers:dart2js_archive_extractor'],
   ),
-  _i1.apply(
-    r'build_resolvers:transitive_digests',
-    [_i8.transitiveDigestsBuilder],
-    _i1.toAllPackages(),
-    isOptional: true,
-    hideOutput: true,
-    appliesBuilders: const [r'build_resolvers:transitive_digest_cleanup'],
-  ),
-  _i1.applyPostProcess(
-    r'build_resolvers:transitive_digest_cleanup',
-    _i8.transitiveDigestCleanup,
-  ),
   _i1.applyPostProcess(
     r'build_modules:module_cleanup',
     _i6.moduleCleanup,
@@ -180,12 +167,12 @@ final _builders = <_i1.BuilderApplication>[
 ];
 void main(
   List<String> args, [
-  _i9.SendPort? sendPort,
+  _i8.SendPort? sendPort,
 ]) async {
-  var result = await _i10.run(
+  var result = await _i9.run(
     args,
     _builders,
   );
   sendPort?.send(result);
-  _i11.exitCode = result;
+  _i10.exitCode = result;
 }

build_resolvers/CHANGELOG.md

@@ -6,6 +6,7 @@
 - Switch `BuildAssetUriResolver` dependency crawl to an iterative
   algorithm, preventing stack overflows.
 - Move `BuildStepImpl` to `build_runner_core`, use `SingleStepReader` directly.
+- Stop building `transitive_digest` files by default.
 
 ## 2.4.4
 

build_resolvers/lib/builder.dart

@@ -10,6 +10,8 @@ import 'package:crypto/crypto.dart';
 
 import 'src/build_asset_uri_resolver.dart';
 
+const transitiveDigestExtension = '.transitive_digest';
+
 Builder transitiveDigestsBuilder(BuilderOptions _) =>
     _TransitiveDigestsBuilder();
 
@@ -24,6 +26,9 @@ PostProcessBuilder transitiveDigestCleanup(BuilderOptions options) =>
 /// For any dependency that has a transitive digest already written, we just use
 /// that and don't crawl its transitive deps, as the transitive digest includes
 /// all the information we need.
+///
+/// TODO(davidmorgan): this is not used by `build_resolvers` any more, consider
+/// deprecating and removing.
 class _TransitiveDigestsBuilder extends Builder {
   @override
   Future<void> build(BuildStep buildStep) async {

build_resolvers/lib/src/analysis_driver_model.dart

@@ -78,10 +78,6 @@ class AnalysisDriverModel {
   /// Notifies [buildStep] of all inputs that result from analysis. If
   /// [transitive], this includes all transitive dependencies.
   ///
-  /// If while finding transitive deps a `.transitive_deps` file is
-  /// encountered next to a source file then this cuts off the reporting
-  /// of deps to the [buildStep], but does not affect the reporting of
-  /// files to the analysis driver.
   Future<void> performResolve(
     BuildStep buildStep,
     List<AssetId> entryPoints,
@@ -176,9 +172,6 @@ extension _AssetIdExtensions on AssetId {
 }
 
 /// The directive graph of all known sources.
-///
-/// Also tracks whether there is a `.transitive_digest` file next to each source
-/// asset, and tracks missing files.
 class _Graph {
   final Map<AssetId, _Node> nodes = {};
 
@@ -208,18 +201,11 @@ class _Graph {
             previouslyMissingFiles.add(id);
           }
           // Load the node.
-          final hasTransitiveDigestAsset = await reader.canRead(
-            id.addExtension(_transitiveDigestExtension),
-          );
           final content = await reader.readAsString(id);
           final deps = _parseDependencies(content, id);
-          node = _Node(
-            id: id,
-            deps: deps,
-            hasTransitiveDigestAsset: hasTransitiveDigestAsset,
-          );
+          node = _Node(id: id, deps: deps);
         } else {
-          node ??= _Node.missing(id: id, hasTransitiveDigestAsset: false);
+          node ??= _Node.missing(id: id);
         }
         nodes[id] = node;
       }
@@ -247,12 +233,6 @@ class _Graph {
       final nextId = nextIds.removeFirst();
       final node = nodes[nextId]!;
 
-      // Add the transitive digest file as an input. If it exists, skip deps.
-      result.add(nextId.addExtension(_transitiveDigestExtension));
-      if (node.hasTransitiveDigestAsset) {
-        continue;
-      }
-
       // Skip if there are no deps because the file is missing.
       if (node.isMissing) continue;
 
@@ -276,27 +256,13 @@ class _Node {
   final AssetId id;
   final List<AssetId> deps;
   final bool isMissing;
-  final bool hasTransitiveDigestAsset;
 
-  _Node({
-    required this.id,
-    required this.deps,
-    required this.hasTransitiveDigestAsset,
-  }) : isMissing = false;
+  _Node({required this.id, required this.deps}) : isMissing = false;
 
-  _Node.missing({required this.id, required this.hasTransitiveDigestAsset})
-    : isMissing = true,
-      deps = const [];
+  _Node.missing({required this.id}) : isMissing = true, deps = const [];
 
   @override
   String toString() =>
       '$id:'
-      '${hasTransitiveDigestAsset ? 'digest:' : ''}'
       '${isMissing ? 'missing' : deps}';
 }
-
-// Transitive digest files are built next to source inputs. As the name
-// suggests, they contain the transitive digest of all deps of the file.
-// So, establishing a dependency on a transitive digest file is equivalent
-// to establishing a dependency on all deps of the file.
-const _transitiveDigestExtension = '.transitive_digest';

build_resolvers/lib/src/build_asset_uri_resolver.dart

@@ -11,7 +11,6 @@ import 'package:analyzer/dart/ast/ast.dart';
 // ignore: implementation_imports
 import 'package:analyzer/src/clients/build_resolvers/build_resolvers.dart';
 import 'package:build/build.dart' show AssetId, BuildStep;
-import 'package:collection/collection.dart';
 import 'package:crypto/crypto.dart';
 import 'package:path/path.dart' as p;
 
@@ -21,8 +20,6 @@ import 'crawl_async.dart';
 
 const _ignoredSchemes = ['dart', 'dart-ext'];
 
-const transitiveDigestExtension = '.transitive_digest';
-
 /// Switches [BuildAssetUriResolver.sharedInstance] from [BuildAssetUriResolver]
 /// to [AnalysisDriverModel].
 void useExperimentalResolver() {
@@ -99,16 +96,7 @@ class BuildAssetUriResolver implements AnalysisDriverModel {
         ),
         (id, state) async {
           if (state == null) return const [];
-          // Establishes a dependency on the transitive deps digest.
-          final hasTransitiveDigestAsset = await buildStep.canRead(
-            id.addExtension(transitiveDigestExtension),
-          );
-          return hasTransitiveDigestAsset
-              // Only crawl assets that we haven't yet loaded into the
-              // analyzer if we are using transitive digests for invalidation.
-              ? state.dependencies.whereNot(_cachedAssetDigests.containsKey)
-              // Otherwise fall back on crawling all source deps.
-              : state.dependencies.where(notCrawled);
+          return state.dependencies.where(notCrawled);
         },
       ).drain<void>();
     } else {

build_resolvers/test/resolver_test.dart

@@ -39,8 +39,6 @@ void runTests(ResolversFactory resolversFactory) {
   final entryPoint = AssetId('a', 'web/main.dart');
   Resolvers createResolvers({PackageConfig? packageConfig}) =>
       resolversFactory.create(packageConfig: packageConfig);
-  final isSharedResolvers = resolversFactory.isInstanceShared;
-
   test('should handle initial files', () {
     return resolveSources({'a|web/main.dart': ' main() {}'}, (resolver) async {
       var lib = await resolver.libraryFor(entryPoint);
@@ -146,84 +144,14 @@ void runTests(ResolversFactory resolversFactory) {
       assetReaderChecks: (reader) {
         expect(reader.testing.inputsTracked, {
           AssetId('a', 'web/main.dart'),
-          AssetId('a', 'web/main.dart.transitive_digest'),
           AssetId('a', 'web/a.dart'),
-          AssetId('a', 'web/a.dart.transitive_digest'),
           AssetId('a', 'web/b.dart'),
-          AssetId('a', 'web/b.dart.transitive_digest'),
         });
       },
       resolvers: createResolvers(),
     );
   });
 
-  test(
-    'transitive_digest file cuts off deps reported to buildStep',
-    // This test requires a new resolvers instance.
-    skip: isSharedResolvers,
-    () async {
-      // BuildAssetUriResolver cuts off a buildStep's deps tree if it encounters
-      // a `.transitive_digest` file, because that file stands in for the
-      // transitive deps from that point.
-      //
-      // But, the _first_ time it is reading files it continues to read them,
-      // because the analyzer still needs all the files. So the first build
-      // action will see all the files as deps.
-      final resolvers = createResolvers();
-      final sources = {
-        'a|web/main.dart': '''
-              import 'a.dart';
-              main() {
-              } ''',
-        'a|web/a.dart': '''
-              library a;
-              import 'b.dart';
-              ''',
-        'a|web/a.dart.transitive_digest': '''
-              library a;
-              import 'b.dart';
-              ''',
-        'a|web/b.dart': '''
-              library b;
-              ''',
-      };
-      // First action sees all the files as inputs.
-      await resolveSources(
-        sources,
-        (resolver) async {
-          await resolver.libraryFor(entryPoint);
-        },
-        assetReaderChecks: (reader) {
-          expect(reader.testing.inputsTracked, {
-            AssetId('a', 'web/main.dart'),
-            AssetId('a', 'web/main.dart.transitive_digest'),
-            AssetId('a', 'web/a.dart'),
-            AssetId('a', 'web/a.dart.transitive_digest'),
-            AssetId('a', 'web/b.dart'),
-            AssetId('a', 'web/b.dart.transitive_digest'),
-          });
-        },
-        resolvers: resolvers,
-      );
-      // Second action has inputs cut off at the `transitive_digest` file.
-      await resolveSources(
-        sources,
-        (resolver) async {
-          await resolver.libraryFor(entryPoint);
-        },
-        assetReaderChecks: (reader) {
-          expect(reader.testing.inputsTracked, {
-            AssetId('a', 'web/main.dart'),
-            AssetId('a', 'web/main.dart.transitive_digest'),
-            AssetId('a', 'web/a.dart'),
-            AssetId('a', 'web/a.dart.transitive_digest'),
-          });
-        },
-        resolvers: resolvers,
-      );
-    },
-  );
-
   test('updates following a change to source', () async {
     var resolvers = createResolvers();
     await resolveSources(
@@ -1398,14 +1326,10 @@ final _skipOnPreRelease =
 
 abstract class ResolversFactory {
   /// Whether [create] returns a shared instance that persists between tests.
-  bool get isInstanceShared;
   Resolvers create({PackageConfig? packageConfig});
 }
 
 class BuildAssetUriResolversFactory implements ResolversFactory {
-  @override
-  bool get isInstanceShared => false;
-
   @override
   Resolvers create({PackageConfig? packageConfig}) => AnalyzerResolvers.custom(
     packageConfig: packageConfig,
@@ -1417,9 +1341,6 @@ class BuildAssetUriResolversFactory implements ResolversFactory {
 }
 
 class SharedBuildAssetUriResolversFactory implements ResolversFactory {
-  @override
-  bool get isInstanceShared => true;
-
   @override
   Resolvers create({PackageConfig? packageConfig}) => AnalyzerResolvers.custom(
     packageConfig: packageConfig,
@@ -1431,9 +1352,6 @@ class SharedBuildAssetUriResolversFactory implements ResolversFactory {
 }
 
 class AnalysisDriverModelFactory implements ResolversFactory {
-  @override
-  bool get isInstanceShared => false;
-
   @override
   Resolvers create({PackageConfig? packageConfig}) => AnalyzerResolvers.custom(
     packageConfig: packageConfig,
@@ -1447,9 +1365,6 @@ class AnalysisDriverModelFactory implements ResolversFactory {
 class SharedAnalysisDriverModelFactory implements ResolversFactory {
   static final AnalysisDriverModel sharedInstance = AnalysisDriverModel();
 
-  @override
-  bool get isInstanceShared => true;
-
   @override
   Resolvers create({PackageConfig? packageConfig}) {
     final result = AnalyzerResolvers.custom(