Clean up test helpers. (#4095)

* Clean up test helpers.

* Address review comments.

Author: davidmorgan

_test_common/lib/assets.dart

@@ -5,6 +5,7 @@
 import 'dart:async';
 
 import 'package:build/build.dart';
+import 'package:built_collection/built_collection.dart';
 
 class CopyingPostProcessBuilder implements PostProcessBuilder {
   final String outputExtension;
@@ -23,18 +24,6 @@ class CopyingPostProcessBuilder implements PostProcessBuilder {
   }
 }
 
-class DeletePostProcessBuilder implements PostProcessBuilder {
-  @override
-  final inputExtensions = ['.txt'];
-
-  DeletePostProcessBuilder();
-
-  @override
-  Future<void> build(PostProcessBuildStep buildStep) async {
-    buildStep.deletePrimaryInput();
-  }
-}
-
 /// A [Builder] which behaves exactly like it's [delegate] but has a different
 /// runtime type.
 class DelegatingBuilder implements Builder {
@@ -48,3 +37,47 @@ class DelegatingBuilder implements Builder {
   @override
   Future build(BuildStep buildStep) async => delegate.build(buildStep);
 }
+
+class PlaceholderBuilder extends Builder {
+  final String inputPlaceholder;
+  final BuiltMap<String, String> outputFilenameToContent;
+
+  @override
+  Map<String, List<String>> get buildExtensions => {
+    // Usually this map is input filename extensions to output filename
+    // extensions, for example `.dart` to `.g.dart`.
+    //
+    // But this builder is about placeholders, which are special keys that
+    // are not extensions. So: the key is a placeholder, and the values are
+    // full output filenames relative to the placeholder path.
+    inputPlaceholder: outputFilenameToContent.keys.toList(),
+  };
+
+  PlaceholderBuilder(
+    this.outputFilenameToContent, {
+    this.inputPlaceholder = r'$lib$',
+  });
+
+  @override
+  Future build(BuildStep buildStep) async {
+    for (final MapEntry(key: outputFilename, value: content)
+        in outputFilenameToContent.entries) {
+      await buildStep.writeAsString(
+        _outputId(buildStep.inputId, inputPlaceholder, outputFilename),
+        content,
+      );
+    }
+  }
+}
+
+AssetId _outputId(
+  AssetId inputId,
+  String inputExtension,
+  String outputExtension,
+) {
+  assert(inputId.path.endsWith(inputExtension));
+  var newPath =
+      inputId.path.substring(0, inputId.path.length - inputExtension.length) +
+      outputExtension;
+  return AssetId(inputId.package, newPath);
+}

_test_common/lib/builders.dart

@@ -2,15 +2,13 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
 import 'dart:convert';
 
 import 'package:build/build.dart';
 import 'package:crypto/crypto.dart';
 
 export 'package:build_test/build_test.dart';
 
-export 'assets.dart';
 export 'builders.dart';
 export 'descriptors.dart';
 export 'matchers.dart';
@@ -25,40 +23,3 @@ Digest computeDigest(AssetId id, String contents) {
 
   return md5.convert([...utf8.encode(contents), ...idString.codeUnits]);
 }
-
-class PlaceholderBuilder extends Builder {
-  final String inputExtension;
-  final Map<String, String> outputExtensionsToContent;
-
-  @override
-  Map<String, List<String>> get buildExtensions => {
-    inputExtension: outputExtensionsToContent.keys.toList(),
-  };
-
-  PlaceholderBuilder(
-    this.outputExtensionsToContent, {
-    this.inputExtension = r'$lib$',
-  });
-
-  @override
-  Future build(BuildStep buildStep) async {
-    outputExtensionsToContent.forEach((extension, content) {
-      buildStep.writeAsString(
-        _outputId(buildStep.inputId, inputExtension, extension),
-        content,
-      );
-    });
-  }
-}
-
-AssetId _outputId(
-  AssetId inputId,
-  String inputExtension,
-  String outputExtension,
-) {
-  assert(inputId.path.endsWith(inputExtension));
-  var newPath =
-      inputId.path.substring(0, inputId.path.length - inputExtension.length) +
-      outputExtension;
-  return AssetId(inputId.package, newPath);
-}

_test_common/lib/common.dart

@@ -2,20 +2,12 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-// ignore: implementation_imports
-import 'package:build_runner_core/src/asset_graph/exceptions.dart';
 // ignore: implementation_imports
 import 'package:build_runner_core/src/asset_graph/graph.dart';
 // ignore: implementation_imports
 import 'package:build_runner_core/src/asset_graph/node.dart';
 import 'package:test/test.dart';
 
-final Matcher throwsCorruptedException = throwsA(
-  const TypeMatcher<AssetGraphCorruptedException>(),
-);
-final Matcher duplicateAssetNodeException =
-    const TypeMatcher<DuplicateAssetNodeException>();
-
 Matcher equalsAssetGraph(AssetGraph expected) => _AssetGraphMatcher(expected);
 
 class _AssetGraphMatcher extends Matcher {

_test_common/lib/matchers.dart

@@ -11,6 +11,7 @@ dependencies:
   build_config: any
   build_runner_core: any
   build_test: any
+  built_collection: any
   crypto: ^3.0.0
   logging: ^1.0.0
   package_config: ^2.0.0

_test_common/lib/test_environment.dart

@@ -418,9 +418,12 @@ targets:
           ..add(aTxtCopyNode)
           ..add(bCopyNode)
           ..add(
-            makeAssetNode('a|web/b.txt', [
-              bCopyNode.id,
-            ], computeDigest(bTxtId, 'b2')),
+            AssetNode.source(
+              AssetId.parse('a|web/b.txt'),
+              outputs: [bCopyNode.id],
+              primaryOutputs: [bCopyNode.id],
+              digest: computeDigest(bTxtId, 'b2'),
+            ),
           );
 
         var cCopyId = makeAssetId('a|web/c.txt.copy');
@@ -437,9 +440,12 @@ targets:
         expectedGraph
           ..add(cCopyNode)
           ..add(
-            makeAssetNode('a|web/c.txt', [
-              cCopyNode.id,
-            ], computeDigest(cTxtId, 'c')),
+            AssetNode.source(
+              AssetId.parse('a|web/c.txt'),
+              outputs: [cCopyNode.id],
+              primaryOutputs: [cCopyNode.id],
+              digest: computeDigest(cTxtId, 'c'),
+            ),
           );
 
         expect(cachedGraph, equalsAssetGraph(expectedGraph));

_test_common/pubspec.yaml

@@ -48,7 +48,8 @@ void main() {
   });
 
   void addAsset(String id, String content, {bool deleted = false}) {
-    var node = makeAssetNode(id, [], computeDigest(AssetId.parse(id), 'a'));
+    final parsedId = AssetId.parse(id);
+    var node = AssetNode.source(parsedId, digest: computeDigest(parsedId, 'a'));
     if (deleted) {
       node = node.rebuild((b) {
         b.deletedBy.add(

build_runner/test/generate/watch_test.dart

@@ -139,7 +139,11 @@ void main() {
   });
 
   void addSource(String id, String content, {bool deleted = false}) {
-    var node = makeAssetNode(id, [], computeDigest(AssetId.parse(id), content));
+    final parsedId = AssetId.parse(id);
+    var node = AssetNode.source(
+      parsedId,
+      digest: computeDigest(parsedId, content),
+    );
     if (deleted) {
       node = node.rebuild((b) {
         b.deletedBy.add(

build_runner/test/server/asset_handler_test.dart

@@ -42,15 +42,13 @@ void main() {
     });
 
     test('can not read deleted files', () async {
-      var notDeleted = makeAssetNode(
-        'a|web/a.txt',
-        [],
-        computeDigest(AssetId('a', 'web/a.txt'), 'a'),
+      var notDeleted = AssetNode.source(
+        AssetId.parse('a|web/a.txt'),
+        digest: computeDigest(AssetId('a', 'web/a.txt'), 'a'),
       );
-      var deleted = makeAssetNode(
-        'a|lib/b.txt',
-        [],
-        computeDigest(AssetId('a', 'lib/b.txt'), 'b'),
+      var deleted = AssetNode.source(
+        AssetId.parse('a|lib/b.txt'),
+        digest: computeDigest(AssetId('a', 'lib/b.txt'), 'b'),
       );
 
       deleted = deleted.rebuild(