Hacking; issue with batch writes.

Author: davidmorgan

_test_common/lib/matchers.dart

@@ -189,10 +189,9 @@ class _AssetGraphMatcher extends Matcher {
         }
       }
     }
-    if (!equals(_expected.packageLanguageVersions).matches(
-      item.packageLanguageVersions,
-      matchState['packageLanguageVersions'] = <String, LanguageVersion?>{},
-    )) {
+    if (!equals(
+      _expected.packageLanguageVersions,
+    ).matches(item.packageLanguageVersions, matchState)) {
       matches = false;
     }
     return matches;

build/lib/src/asset/exceptions.dart

@@ -5,11 +5,15 @@ import 'id.dart';
 
 class AssetNotFoundException implements Exception {
   final AssetId assetId;
+  final String? path;
 
-  AssetNotFoundException(this.assetId);
+  AssetNotFoundException(this.assetId, {this.path});
 
   @override
-  String toString() => 'AssetNotFoundException: $assetId';
+  String toString() {
+    if (path == null) return 'AssetNotFoundException: $assetId';
+    return 'AssetNotFoundException: $assetId ($path)';
+  }
 }
 
 class PackageNotFoundException implements Exception {

build/lib/src/state/asset_path_provider.dart

@@ -4,18 +4,7 @@
 
 import '../asset/id.dart';
 
-/// Converts [AssetId] to paths.
+/// Converts [AssetId]s to paths.
 abstract interface class AssetPathProvider {
   String pathFor(AssetId id);
 }
-
-/// Applies a function to an existing [AssetPathProvider].
-class OverlayAssetPathProvider implements AssetPathProvider {
-  AssetPathProvider delegate;
-  AssetId Function(AssetId) overlay;
-
-  OverlayAssetPathProvider({required this.delegate, required this.overlay});
-
-  @override
-  String pathFor(AssetId id) => delegate.pathFor(overlay(id));
-}

build_runner_core/lib/src/asset/batch.dart

@@ -58,6 +58,7 @@ final class _FileSystemWriteBatch {
   required AssetReader reader,
   required RunnerAssetWriter writer,
 }) {
+  throw 'nope';
   final batch = _FileSystemWriteBatch._();
 
   return (BatchReader(reader, batch), BatchWriter(writer, batch));
@@ -165,6 +166,9 @@ final class BatchWriter extends RunnerAssetWriter {
 
   @override
   Future<void> writeAsBytes(AssetId id, List<int> bytes) async {
+    if (id.path.contains('.dart_tool')) {
+      throw 'whoops: $id, ${StackTrace.current}';
+    }
     _batch._pendingWrites[id] = _PendingFileState(bytes);
   }
 
@@ -174,6 +178,9 @@ final class BatchWriter extends RunnerAssetWriter {
     String contents, {
     Encoding encoding = utf8,
   }) async {
+    if (id.path.contains('.dart_tool')) {
+      throw 'whoops: $id';
+    }
     _batch._pendingWrites[id] = _PendingFileState(encoding.encode(contents));
   }
 

build_runner_core/lib/src/asset/build_cache.dart

@@ -68,19 +68,24 @@ class BuildCacheWriter implements RunnerAssetWriter {
 }
 
 AssetId _cacheLocation(AssetId id, AssetGraph assetGraph, String rootPackage) {
+  print('_cacheLocation $id');
   if (id.path.startsWith(generatedOutputDirectory) ||
       id.path.startsWith(cacheDir)) {
+    print('--> return 1');
     return id;
   }
   if (!assetGraph.contains(id)) {
+    print('--> return 2');
     return id;
   }
   final assetNode = assetGraph.get(id);
   if (assetNode is GeneratedAssetNode && assetNode.isHidden) {
+    print('--> hit');
     return AssetId(
       rootPackage,
       '$generatedOutputDirectory/${id.package}/${id.path}',
     );
   }
+  print('--> return 3');
   return id;
 }

build_runner_core/lib/src/asset/file_based.dart

@@ -13,6 +13,7 @@ import 'package:glob/list_local_fs.dart';
 import 'package:path/path.dart' as path;
 
 import '../package_graph/package_graph.dart';
+import 'build_cache.dart';
 import 'writer.dart';
 
 /// Basic [AssetReader] which uses a [PackageGraph] to look up where to read
@@ -44,9 +45,9 @@ class FileBasedAssetReader extends AssetReader implements AssetReaderState {
     FilesystemCache? cache,
   }) => FileBasedAssetReader(
     packageGraph,
-    assetPathProvider: assetPathProvider,
+    assetPathProvider: assetPathProvider ?? this.assetPathProvider,
     filesystem: filesystem,
-    cache: cache,
+    cache: cache ?? this.cache,
   );
 
   @override
@@ -70,8 +71,10 @@ class FileBasedAssetReader extends AssetReader implements AssetReaderState {
       ifAbsent: () async {
         final path = assetPathProvider.pathFor(id);
         if (!await filesystem.exists(path)) {
-          // TODO(davidmorgan): report the path as well?
-          throw AssetNotFoundException(id);
+          print(
+            '${assetPathProvider.runtimeType} is missing $path at ${StackTrace.current}',
+          );
+          throw AssetNotFoundException(id, path: path);
         }
         return filesystem.readAsBytes(path);
       },
@@ -86,7 +89,8 @@ class FileBasedAssetReader extends AssetReader implements AssetReaderState {
       ifAbsent: () async {
         final path = assetPathProvider.pathFor(id);
         if (!await filesystem.exists(path)) {
-          throw AssetNotFoundException(id);
+          print('${assetPathProvider.runtimeType} is missing $path');
+          throw AssetNotFoundException(id, path: path);
         }
         return filesystem.readAsBytes(path);
       },

build_runner_core/lib/src/environment/io_environment.dart

@@ -46,7 +46,7 @@ class IOEnvironment implements BuildEnvironment {
     PackageGraph packageGraph, {
     bool? assumeTty,
     bool outputSymlinksOnly = false,
-    bool lowResourcesMode = false,
+    //bool lowResourcesMode = false,
   }) {
     if (outputSymlinksOnly && Platform.isWindows) {
       _logger.warning(
@@ -60,7 +60,7 @@ class IOEnvironment implements BuildEnvironment {
     var fileWriter = FileBasedAssetWriter(packageGraph);
 
     var (reader, writer) =
-        lowResourcesMode
+        true
             ? (fileReader, fileWriter)
             : wrapInBatch(reader: fileReader, writer: fileWriter);