[flutter_tools] refactor build_system and targets to be context-free (#53268)

packages/flutter_tools/lib/src/aot.dart

@@ -95,7 +95,11 @@ class AotBuilder {
           kExtraFrontEndOptions: buildInfo.extraFrontEndOptions.join(','),
         if (platform == TargetPlatform.ios)
           kIosArchs: iosBuildArchs.map(getNameForDarwinArch).join(' ')
-      }
+      },
+      artifacts: globals.artifacts,
+      fileSystem: globals.fs,
+      logger: globals.logger,
+      processManager: globals.processManager,
     );
     final BuildResult result = await globals.buildSystem.build(target, environment);
     status?.stop();

packages/flutter_tools/lib/src/base/logger.dart

@@ -382,7 +382,7 @@ class BufferLogger extends Logger {
        _timeoutConfiguration = timeoutConfiguration,
        _stopwatchFactory = stopwatchFactory;
 
-  @visibleForTesting
+  /// Create a [BufferLogger] with test preferences.
   BufferLogger.test({
     Terminal terminal,
     OutputPreferences outputPreferences,

packages/flutter_tools/lib/src/build_system/build_system.dart

@@ -8,13 +8,16 @@ import 'package:async/async.dart';
 import 'package:convert/convert.dart';
 import 'package:crypto/crypto.dart';
 import 'package:meta/meta.dart';
+import 'package:platform/platform.dart';
 import 'package:pool/pool.dart';
+import 'package:process/process.dart';
 
+import '../artifacts.dart';
 import '../base/file_system.dart';
+import '../base/logger.dart';
 import '../base/utils.dart';
 import '../cache.dart';
 import '../convert.dart';
-import '../globals.dart' as globals;
 import 'exceptions.dart';
 import 'file_hash_store.dart';
 import 'source.dart';
@@ -286,6 +289,10 @@ class Environment {
     @required Directory outputDir,
     @required Directory cacheDir,
     @required Directory flutterRootDir,
+    @required FileSystem fileSystem,
+    @required Logger logger,
+    @required Artifacts artifacts,
+    @required ProcessManager processManager,
     Directory buildDir,
     Map<String, String> defines = const <String, String>{},
   }) {
@@ -314,6 +321,10 @@ class Environment {
       cacheDir: cacheDir,
       defines: defines,
       flutterRootDir: flutterRootDir,
+      fileSystem: fileSystem,
+      logger: logger,
+      artifacts: artifacts,
+      processManager: processManager,
     );
   }
 
@@ -327,6 +338,10 @@ class Environment {
     Directory flutterRootDir,
     Directory buildDir,
     Map<String, String> defines = const <String, String>{},
+    @required FileSystem fileSystem,
+    @required Logger logger,
+    @required Artifacts artifacts,
+    @required ProcessManager processManager,
   }) {
     return Environment(
       projectDir: projectDir ?? testDirectory,
@@ -335,6 +350,10 @@ class Environment {
       flutterRootDir: flutterRootDir ?? testDirectory,
       buildDir: buildDir,
       defines: defines,
+      fileSystem: fileSystem,
+      logger: logger,
+      artifacts: artifacts,
+      processManager: processManager,
     );
   }
 
@@ -346,6 +365,10 @@ class Environment {
     @required this.cacheDir,
     @required this.defines,
     @required this.flutterRootDir,
+    @required this.processManager,
+    @required this.logger,
+    @required this.fileSystem,
+    @required this.artifacts,
   });
 
   /// The [Source] value which is substituted with the path to [projectDir].
@@ -399,6 +422,14 @@ class Environment {
 
   /// The root build directory shared by all builds.
   final Directory rootBuildDir;
+
+  final ProcessManager processManager;
+
+  final Logger logger;
+
+  final Artifacts artifacts;
+
+  final FileSystem fileSystem;
 }
 
 /// The result information from the build system.
@@ -422,7 +453,17 @@ class BuildResult {
 
 /// The build system is responsible for invoking and ordering [Target]s.
 class BuildSystem {
-  const BuildSystem();
+  const BuildSystem({
+    @required FileSystem fileSystem,
+    @required Platform platform,
+    @required Logger logger,
+  }) : _fileSystem = fileSystem,
+       _platform = platform,
+       _logger = logger;
+
+  final FileSystem _fileSystem;
+  final Platform _platform;
+  final Logger _logger;
 
   /// Build `target` and all of its dependencies.
   Future<BuildResult> build(
@@ -436,15 +477,22 @@ class BuildSystem {
     // Load file hash store from previous builds.
     final FileHashStore fileCache = FileHashStore(
       environment: environment,
-      fileSystem: globals.fs,
-      logger: globals.logger,
+      fileSystem: _fileSystem,
+      logger: _logger,
     )..initialize();
 
     // Perform sanity checks on build.
     checkCycles(target);
 
     final Node node = target._toNode(environment);
-    final _BuildInstance buildInstance = _BuildInstance(environment, fileCache, buildSystemConfig);
+    final _BuildInstance buildInstance = _BuildInstance(
+      environment: environment,
+      fileCache: fileCache,
+      buildSystemConfig: buildSystemConfig,
+      logger: _logger,
+      fileSystem: _fileSystem,
+      platform: _platform,
+    );
     bool passed = true;
     try {
       passed = await buildInstance.invokeTarget(node);
@@ -486,9 +534,18 @@ class BuildSystem {
 
 /// An active instance of a build.
 class _BuildInstance {
-  _BuildInstance(this.environment, this.fileCache, this.buildSystemConfig)
-    : resourcePool = Pool(buildSystemConfig.resourcePoolSize ?? globals.platform?.numberOfProcessors ?? 1);
-
+  _BuildInstance({
+    this.environment,
+    this.fileCache,
+    this.buildSystemConfig,
+    this.logger,
+    this.fileSystem,
+    Platform platform,
+  })
+    : resourcePool = Pool(buildSystemConfig.resourcePoolSize ?? platform?.numberOfProcessors ?? 1);
+
+  final Logger logger;
+  final FileSystem fileSystem;
   final BuildSystemConfig buildSystemConfig;
   final Pool resourcePool;
   final Map<String, AsyncMemoizer<bool>> pending = <String, AsyncMemoizer<bool>>{};
@@ -545,17 +602,17 @@ class _BuildInstance {
       // If we're missing a depfile, wait until after evaluating the target to
       // compute changes.
       final bool canSkip = !node.missingDepfile &&
-        await node.computeChanges(environment, fileCache);
+        await node.computeChanges(environment, fileCache, fileSystem, logger);
 
       if (canSkip) {
         skipped = true;
-        globals.printTrace('Skipping target: ${node.target.name}');
+        logger.printTrace('Skipping target: ${node.target.name}');
         updateGraph();
         return passed;
       }
-      globals.printTrace('${node.target.name}: Starting due to ${node.invalidatedReasons}');
+      logger.printTrace('${node.target.name}: Starting due to ${node.invalidatedReasons}');
       await node.target.build(environment);
-      globals.printTrace('${node.target.name}: Complete');
+      logger.printTrace('${node.target.name}: Complete');
 
       node.inputs
         ..clear()
@@ -581,7 +638,7 @@ class _BuildInstance {
         if (outputFiles.containsKey(previousOutput)) {
           continue;
         }
-        final File previousFile = globals.fs.file(previousOutput);
+        final File previousFile = fileSystem.file(previousOutput);
         if (previousFile.existsSync()) {
           previousFile.deleteSync();
         }
@@ -771,6 +828,8 @@ class Node {
   Future<bool> computeChanges(
     Environment environment,
     FileHashStore fileHashStore,
+    FileSystem fileSystem,
+    Logger logger,
   ) async {
     final Set<String> currentOutputPaths = <String>{
       for (final File file in outputs) file.path,
@@ -808,7 +867,7 @@ class Node {
         // if this isn't a current output file there is no reason to compute the hash.
         continue;
       }
-      final File file = globals.fs.file(previousOutput);
+      final File file = fileSystem.file(previousOutput);
       if (!file.existsSync()) {
         invalidatedReasons.add(InvalidatedReason.outputMissing);
         _dirty = true;
@@ -833,7 +892,7 @@ class Node {
     if (missingInputs.isNotEmpty) {
       _dirty = true;
       final String missingMessage = missingInputs.map((File file) => file.path).join(', ');
-      globals.printTrace('invalidated build due to missing files: $missingMessage');
+      logger.printTrace('invalidated build due to missing files: $missingMessage');
       invalidatedReasons.add(InvalidatedReason.inputMissing);
     }
 

packages/flutter_tools/lib/src/build_system/source.dart

@@ -5,7 +5,6 @@
 import '../artifacts.dart';
 import '../base/file_system.dart';
 import '../build_info.dart';
-import '../globals.dart' as globals;
 import 'build_system.dart';
 import 'exceptions.dart';
 
@@ -24,7 +23,7 @@ abstract class ResolvedFiles {
 /// Collects sources for a [Target] into a single list of [FileSystemEntities].
 class SourceVisitor implements ResolvedFiles {
   /// Create a new [SourceVisitor] from an [Environment].
-  SourceVisitor(this.environment, [this.inputs = true]);
+  SourceVisitor(this.environment, [ this.inputs = true ]);
 
   /// The current environment.
   final Environment environment;
@@ -56,7 +55,7 @@ class SourceVisitor implements ResolvedFiles {
     final String contents = depfile.readAsStringSync();
     final List<String> colonSeparated = contents.split(': ');
     if (colonSeparated.length != 2) {
-      globals.printError('Invalid depfile: ${depfile.path}');
+      environment.logger.printError('Invalid depfile: ${depfile.path}');
       return;
     }
     if (inputs) {
@@ -78,7 +77,7 @@ class SourceVisitor implements ResolvedFiles {
         .map<String>((String path) => path.replaceAllMapped(_escapeExpr, (Match match) => match.group(1)).trim())
         .where((String path) => path.isNotEmpty)
         .toSet()
-        .map((String path) => globals.fs.file(path));
+        .map(environment.fileSystem.file);
   }
 
   /// Visit a [Source] which contains a file URL.
@@ -101,35 +100,36 @@ class SourceVisitor implements ResolvedFiles {
     switch (rawParts.first) {
       case Environment.kProjectDirectory:
         segments.addAll(
-            globals.fs.path.split(environment.projectDir.resolveSymbolicLinksSync()));
+          environment.fileSystem.path.split(environment.projectDir.resolveSymbolicLinksSync()));
         break;
       case Environment.kBuildDirectory:
-        segments.addAll(globals.fs.path.split(
-            environment.buildDir.resolveSymbolicLinksSync()));
+        segments.addAll(environment.fileSystem.path.split(
+          environment.buildDir.resolveSymbolicLinksSync()));
         break;
       case Environment.kCacheDirectory:
         segments.addAll(
-            globals.fs.path.split(environment.cacheDir.resolveSymbolicLinksSync()));
+          environment.fileSystem.path.split(environment.cacheDir.resolveSymbolicLinksSync()));
         break;
       case Environment.kFlutterRootDirectory:
         // flutter root will not contain a symbolic link.
         segments.addAll(
-            globals.fs.path.split(environment.flutterRootDir.absolute.path));
+          environment.fileSystem.path.split(environment.flutterRootDir.absolute.path));
         break;
       case Environment.kOutputDirectory:
         segments.addAll(
-            globals.fs.path.split(environment.outputDir.resolveSymbolicLinksSync()));
+          environment.fileSystem.path.split(environment.outputDir.resolveSymbolicLinksSync()));
         break;
       default:
         throw InvalidPatternException(pattern);
     }
     rawParts.skip(1).forEach(segments.add);
-    final String filePath = globals.fs.path.joinAll(segments);
+    final String filePath = environment.fileSystem.path.joinAll(segments);
     if (!hasWildcard) {
-      if (optional && !globals.fs.isFileSync(filePath)) {
+      if (optional && !environment.fileSystem.isFileSync(filePath)) {
         return;
       }
-      sources.add(globals.fs.file(globals.fs.path.normalize(filePath)));
+      sources.add(environment.fileSystem.file(
+        environment.fileSystem.path.normalize(filePath)));
       return;
     }
     // Perform a simple match by splitting the wildcard containing file one
@@ -143,21 +143,21 @@ class SourceVisitor implements ResolvedFiles {
     if (wildcardSegments.length > 2) {
       throw InvalidPatternException(pattern);
     }
-    if (!globals.fs.directory(filePath).existsSync()) {
+    if (!environment.fileSystem.directory(filePath).existsSync()) {
       throw Exception('$filePath does not exist!');
     }
-    for (final FileSystemEntity entity in globals.fs.directory(filePath).listSync()) {
-      final String filename = globals.fs.path.basename(entity.path);
+    for (final FileSystemEntity entity in environment.fileSystem.directory(filePath).listSync()) {
+      final String filename = environment.fileSystem.path.basename(entity.path);
       if (wildcardSegments.isEmpty) {
-        sources.add(globals.fs.file(entity.absolute));
+        sources.add(environment.fileSystem.file(entity.absolute));
       } else if (wildcardSegments.length == 1) {
         if (filename.startsWith(wildcardSegments[0]) ||
             filename.endsWith(wildcardSegments[0])) {
-          sources.add(globals.fs.file(entity.absolute));
+          sources.add(environment.fileSystem.file(entity.absolute));
         }
       } else if (filename.startsWith(wildcardSegments[0])) {
         if (filename.substring(wildcardSegments[0].length).endsWith(wildcardSegments[1])) {
-          sources.add(globals.fs.file(entity.absolute));
+          sources.add(environment.fileSystem.file(entity.absolute));
         }
       }
     }
@@ -167,15 +167,16 @@ class SourceVisitor implements ResolvedFiles {
   ///
   /// If the [Artifact] points to a directory then all child files are included.
   void visitArtifact(Artifact artifact, TargetPlatform platform, BuildMode mode) {
-    final String path = globals.artifacts.getArtifactPath(artifact, platform: platform, mode: mode);
-    if (globals.fs.isDirectorySync(path)) {
+    final String path = environment.artifacts
+      .getArtifactPath(artifact, platform: platform, mode: mode);
+    if (environment.fileSystem.isDirectorySync(path)) {
       sources.addAll(<File>[
-        for (FileSystemEntity entity in globals.fs.directory(path).listSync(recursive: true))
+        for (FileSystemEntity entity in environment.fileSystem.directory(path).listSync(recursive: true))
           if (entity is File)
             entity,
       ]);
     } else {
-      sources.add(globals.fs.file(path));
+      sources.add(environment.fileSystem.file(path));
     }
   }
 }

packages/flutter_tools/lib/src/build_system/targets/windows.dart

@@ -5,7 +5,6 @@
 import '../../artifacts.dart';
 import '../../base/file_system.dart';
 import '../../build_info.dart';
-import '../../globals.dart' as globals;
 import '../build_system.dart';
 
 /// Copies the Windows desktop embedding files to the copy directory.
@@ -40,21 +39,24 @@ class UnpackWindows extends Target {
   @override
   Future<void> build(Environment environment) async {
     // This path needs to match the prefix in the rule below.
-    final String basePath = globals.artifacts.getArtifactPath(Artifact.windowsDesktopPath);
-    for (final File input in globals.fs.directory(basePath)
+    final String basePath = environment.artifacts
+      .getArtifactPath(Artifact.windowsDesktopPath);
+    for (final File input in environment.fileSystem.directory(basePath)
         .listSync(recursive: true)
         .whereType<File>()) {
-      final String outputPath = globals.fs.path.join(
+      final String outputPath = environment.fileSystem.path.join(
         environment.projectDir.path,
         'windows',
         'flutter',
-        globals.fs.path.relative(input.path, from: basePath),
+        environment.fileSystem.path
+          .relative(input.path, from: basePath),
       );
-      final File destinationFile = globals.fs.file(outputPath);
+      final File destinationFile = environment.fileSystem.file(outputPath);
       if (!destinationFile.parent.existsSync()) {
         destinationFile.parent.createSync(recursive: true);
       }
-      globals.fs.file(input).copySync(destinationFile.path);
+      environment.fileSystem
+        .file(input).copySync(destinationFile.path);
     }
   }
 }

packages/flutter_tools/lib/src/bundle.dart

@@ -132,6 +132,10 @@ Future<void> buildWithAssemble({
       if (dartDefines != null && dartDefines.isNotEmpty)
         kDartDefines: jsonEncode(dartDefines),
     },
+    artifacts: globals.artifacts,
+    fileSystem: globals.fs,
+    logger: globals.logger,
+    processManager: globals.processManager,
   );
   final Target target = buildMode == BuildMode.debug
     ? const CopyFlutterBundle()

packages/flutter_tools/lib/src/commands/assemble.dart

@@ -151,6 +151,10 @@ class AssembleCommand extends FlutterCommand {
       defines: _parseDefines(stringsArg('define')),
       cacheDir: globals.cache.getRoot(),
       flutterRootDir: globals.fs.directory(Cache.flutterRoot),
+      artifacts: globals.artifacts,
+      fileSystem: globals.fs,
+      logger: globals.logger,
+      processManager: globals.processManager,
     );
     return result;
   }

packages/flutter_tools/lib/src/context_runner.dart

@@ -89,7 +89,11 @@ Future<T> runInContext<T>(
         platform: globals.platform,
       ),
       AssetBundleFactory: () => AssetBundleFactory.defaultInstance,
-      BuildSystem: () => const BuildSystem(),
+      BuildSystem: () => BuildSystem(
+        fileSystem: globals.fs,
+        logger: globals.logger,
+        platform: globals.platform,
+      ),
       Cache: () => Cache(
         fileSystem: globals.fs,
         logger: globals.logger,

packages/flutter_tools/lib/src/web/compile.dart

@@ -53,6 +53,10 @@ Future<void> buildWeb(
         kCspMode: csp.toString(),
         kIconTreeShakerFlag: buildInfo.treeShakeIcons.toString(),
       },
+      artifacts: globals.artifacts,
+      fileSystem: globals.fs,
+      logger: globals.logger,
+      processManager: globals.processManager,
     ));
     if (!result.success) {
       for (final ExceptionMeasurement measurement in result.exceptions.values) {

packages/flutter_tools/test/general.shard/build_system/filecache_test.dart

@@ -5,6 +5,7 @@
 import 'dart:typed_data';
 
 import 'package:file/memory.dart';
+import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/base/terminal.dart';
@@ -14,6 +15,7 @@ import 'package:mockito/mockito.dart';
 import 'package:platform/platform.dart';
 
 import '../../src/common.dart';
+import '../../src/fake_process_manager.dart';
 
 void main() {
   Environment environment;
@@ -29,6 +31,10 @@ void main() {
     fileSystem.directory('build').createSync();
     environment = Environment.test(
       fileSystem.currentDirectory,
+      artifacts: MockArtifacts(),
+      processManager: FakeProcessManager.any(),
+      logger: logger,
+      fileSystem: fileSystem,
     );
     environment.buildDir.createSync(recursive: true);
   });
@@ -168,4 +174,6 @@ class FakeForwardingFileSystem extends ForwardingFileSystem {
   @override
   File file(dynamic path) => files[path] ?? super.file(path);
 }
+
 class MockFile extends Mock implements File {}
+class MockArtifacts extends Mock implements Artifacts {}

packages/flutter_tools/test/general.shard/build_system/source_test.dart

@@ -14,6 +14,7 @@ import 'package:mockito/mockito.dart';
 import 'package:platform/platform.dart';
 
 import '../../src/common.dart';
+import '../../src/context.dart';
 import '../../src/testbed.dart';
 
 void main() {
@@ -32,6 +33,10 @@ void main() {
       environment = Environment.test(
         globals.fs.currentDirectory,
         outputDir: outputs,
+        artifacts: globals.artifacts, // using real artifacts
+        processManager: FakeProcessManager.any(),
+        fileSystem: globals.fs,
+        logger: globals.logger,
       );
       visitor = SourceVisitor(environment);
       environment.buildDir.createSync(recursive: true);
@@ -212,3 +217,4 @@ void main() {
 }
 
 class MockPlatform extends Mock implements Platform {}
+class MockArtifacts extends Mock implements Artifacts {}

packages/flutter_tools/test/general.shard/build_system/targets/android_test.dart

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/build_system/build_system.dart';
@@ -9,6 +10,7 @@ import 'package:flutter_tools/src/build_system/targets/android.dart';
 import 'package:flutter_tools/src/build_system/targets/dart.dart';
 import 'package:flutter_tools/src/globals.dart' as globals;
 import 'package:flutter_tools/src/cache.dart';
+import 'package:mockito/mockito.dart';
 import 'package:platform/platform.dart';
 
 import '../../../src/common.dart';
@@ -32,7 +34,11 @@ void main() {
       outputDir: globals.fs.directory('out')..createSync(),
       defines: <String, String>{
         kBuildMode: 'debug',
-      }
+      },
+      processManager: fakeProcessManager,
+      artifacts: MockArtifacts(),
+      fileSystem: globals.fs,
+      logger: globals.logger,
     );
     environment.buildDir.createSync(recursive: true);
 
@@ -45,7 +51,6 @@ void main() {
     hostDirectory.childFile('vm_isolate_snapshot.bin').createSync();
     hostDirectory.childFile('isolate_snapshot.bin').createSync();
 
-
     await const DebugAndroidApplication().build(environment);
 
     expect(globals.fs.file(globals.fs.path.join('out', 'flutter_assets', 'isolate_snapshot_data')).existsSync(), true);
@@ -59,7 +64,11 @@ void main() {
       outputDir: globals.fs.directory('out')..createSync(),
       defines: <String, String>{
         kBuildMode: 'profile',
-      }
+      },
+      artifacts: MockArtifacts(),
+      processManager: fakeProcessManager,
+      fileSystem: globals.fs,
+      logger: globals.logger,
     );
     environment.buildDir.createSync(recursive: true);
 
@@ -78,7 +87,11 @@ void main() {
       outputDir: globals.fs.directory('out')..createSync(),
       defines: <String, String>{
         kBuildMode: 'release',
-      }
+      },
+      artifacts: MockArtifacts(),
+      processManager: fakeProcessManager,
+      fileSystem: globals.fs,
+      logger: globals.logger,
     );
     environment.buildDir.createSync(recursive: true);
 
@@ -92,15 +105,19 @@ void main() {
   });
 
   testbed.test('AndroidAot can build provided target platform', () async {
+    fakeProcessManager = FakeProcessManager.list(<FakeCommand>[]);
     final Environment environment = Environment.test(
       globals.fs.currentDirectory,
       outputDir: globals.fs.directory('out')..createSync(),
       defines: <String, String>{
         kBuildMode: 'release',
-      }
+      },
+      artifacts: MockArtifacts(),
+      processManager: FakeProcessManager.list(<FakeCommand>[]),
+      fileSystem: globals.fs,
+      logger: globals.logger,
     );
-    fakeProcessManager = FakeProcessManager.list(<FakeCommand>[
-      FakeCommand(command: <String>[
+    fakeProcessManager.addCommand(FakeCommand(command: <String>[
         globals.fs.path.absolute(globals.fs.path.join('android-arm64-release', 'linux-x64', 'gen_snapshot')),
         '--deterministic',
         '--snapshot_kind=app-aot-elf',
@@ -111,18 +128,21 @@ void main() {
         environment.buildDir.childFile('app.dill').path,
         ],
       )
-    ]);
+    );
     environment.buildDir.createSync(recursive: true);
     environment.buildDir.childFile('app.dill').createSync();
     environment.projectDir.childFile('.packages').writeAsStringSync('\n');
     const AndroidAot androidAot = AndroidAot(TargetPlatform.android_arm64, BuildMode.release);
 
     await androidAot.build(environment);
+
+    expect(fakeProcessManager.hasRemainingExpectations, false);
   }, overrides: <Type, Generator>{
     ProcessManager: () => fakeProcessManager,
   });
 
   testbed.test('kExtraGenSnapshotOptions passes values to gen_snapshot', () async {
+    fakeProcessManager = FakeProcessManager.list(<FakeCommand>[]);
     final Environment environment = Environment.test(
       globals.fs.currentDirectory,
       outputDir: globals.fs.directory('out')..createSync(),
@@ -130,9 +150,13 @@ void main() {
         kBuildMode: 'release',
         kExtraGenSnapshotOptions: 'foo,bar,baz=2',
         kTargetPlatform: 'android-arm',
-      }
+      },
+      processManager: fakeProcessManager,
+      artifacts: MockArtifacts(),
+      fileSystem: globals.fs,
+      logger: globals.logger,
     );
-    fakeProcessManager = FakeProcessManager.list(<FakeCommand>[
+    fakeProcessManager.addCommand(
       FakeCommand(command: <String>[
          globals.fs.path.absolute(globals.fs.path.join('android-arm64-release', 'linux-x64', 'gen_snapshot')),
         '--deterministic',
@@ -145,8 +169,7 @@ void main() {
         '--no-causal-async-stacks',
         '--lazy-async-stacks',
         environment.buildDir.childFile('app.dill').path
-      ])
-    ]);
+      ]));
     environment.buildDir.createSync(recursive: true);
     environment.buildDir.childFile('app.dill').createSync();
     environment.projectDir.childFile('.packages').writeAsStringSync('\n');
@@ -163,7 +186,11 @@ void main() {
       outputDir: globals.fs.directory('out')..createSync(),
       defines: <String, String>{
         kBuildMode: 'release',
-      }
+      },
+      processManager: fakeProcessManager,
+      artifacts: MockArtifacts(),
+      fileSystem: globals.fs,
+      logger: globals.logger,
     );
     environment.buildDir.createSync(recursive: true);
     const AndroidAot androidAot = AndroidAot(TargetPlatform.android_arm64, BuildMode.release);
@@ -181,3 +208,5 @@ void main() {
       .childFile('app.so').existsSync(), true);
   });
 }
+
+class MockArtifacts extends Mock implements Artifacts {}
\ No newline at end of file

packages/flutter_tools/test/general.shard/build_system/targets/assets_test.dart

@@ -4,10 +4,13 @@
 
 import 'package:file/memory.dart';
 import 'package:file_testing/file_testing.dart';
+import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
+import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/build_system/build_system.dart';
 import 'package:flutter_tools/src/build_system/depfile.dart';
 import 'package:flutter_tools/src/build_system/targets/assets.dart';
+import 'package:mockito/mockito.dart';
 import 'package:platform/platform.dart';
 
 import '../../../src/common.dart';
@@ -23,6 +26,10 @@ void main() {
     fileSystem = MemoryFileSystem.test();
     environment = Environment.test(
       fileSystem.currentDirectory,
+      processManager: FakeProcessManager.any(),
+      artifacts: MockArtifacts(),
+      fileSystem: fileSystem,
+      logger: BufferLogger.test(),
     );
     fileSystem.file(environment.buildDir.childFile('app.dill')).createSync(recursive: true);
     fileSystem.file('packages/flutter_tools/lib/src/build_system/targets/assets.dart')
@@ -91,3 +98,5 @@ flutter:
     Platform: () => platform,
   });
 }
+
+class MockArtifacts extends Mock implements Artifacts {}

packages/flutter_tools/test/general.shard/build_system/targets/dart_test.dart

@@ -43,6 +43,10 @@ void main() {
           kBuildMode: getNameForBuildMode(BuildMode.profile),
           kTargetPlatform: getNameForTargetPlatform(TargetPlatform.android_arm),
         },
+        artifacts: artifacts,
+        processManager: processManager,
+        fileSystem: globals.fs,
+        logger: globals.logger,
       );
       androidEnvironment.buildDir.createSync(recursive: true);
       iosEnvironment = Environment.test(
@@ -51,6 +55,10 @@ void main() {
           kBuildMode: getNameForBuildMode(BuildMode.profile),
           kTargetPlatform: getNameForTargetPlatform(TargetPlatform.ios),
         },
+        artifacts: artifacts,
+        processManager: processManager,
+        fileSystem: globals.fs,
+        logger: globals.logger,
       );
       iosEnvironment.buildDir.createSync(recursive: true);
       artifacts = CachedArtifacts(
@@ -261,6 +269,10 @@ void main() {
         kBuildMode: getNameForBuildMode(BuildMode.debug),
         kTargetPlatform: getNameForTargetPlatform(TargetPlatform.android_arm),
       },
+      processManager: processManager,
+      artifacts: artifacts,
+      fileSystem: globals.fs,
+      logger: globals.logger,
     );
     final String build = testEnvironment.buildDir.path;
     processManager = FakeProcessManager.list(<FakeCommand>[

packages/flutter_tools/test/general.shard/build_system/targets/icon_tree_shaker_test.dart

@@ -113,6 +113,10 @@ void main() {
     return Environment.test(
       fs.directory('/icon_test')..createSync(recursive: true),
       defines: defines,
+      artifacts: mockArtifacts,
+      processManager: FakeProcessManager.any(),
+      fileSystem: fs,
+      logger: BufferLogger.test(),
     );
   }
 

packages/flutter_tools/test/general.shard/build_system/targets/ios_test.dart

@@ -39,9 +39,16 @@ void main() {
 
   setUp(() {
     testbed = Testbed(setup: () {
-      environment = Environment.test(globals.fs.currentDirectory, defines: <String, String>{
-        kTargetPlatform: 'ios',
-      });
+      environment = Environment.test(
+        globals.fs.currentDirectory,
+        defines: <String, String>{
+          kTargetPlatform: 'ios',
+        },
+        processManager: processManager,
+        artifacts: MockArtifacts(),
+        logger: globals.logger,
+        fileSystem: globals.fs,
+      );
     });
   });
 

packages/flutter_tools/test/general.shard/build_system/targets/linux_test.dart

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'package:flutter_tools/src/artifacts.dart';
 import 'package:platform/platform.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/build_system/build_system.dart';
@@ -12,11 +13,12 @@ import 'package:flutter_tools/src/globals.dart' as globals;
 import 'package:mockito/mockito.dart';
 
 import '../../../src/common.dart';
+import '../../../src/context.dart';
 import '../../../src/testbed.dart';
 
 void main() {
   Testbed testbed;
-  const BuildSystem buildSystem = BuildSystem();
+  BuildSystem buildSystem;
   Environment environment;
   MockPlatform mockPlatform;
 
@@ -33,11 +35,20 @@ void main() {
     when(mockPlatform.environment).thenReturn(Map<String, String>.unmodifiable(<String, String>{}));
     testbed = Testbed(setup: () {
       Cache.flutterRoot = '';
+      buildSystem = BuildSystem(
+        logger: globals.logger,
+        platform: globals.platform,
+        fileSystem: globals.fs,
+      );
       environment = Environment.test(
         globals.fs.currentDirectory,
         defines: <String, String>{
           kBuildMode: 'debug',
-        }
+        },
+        artifacts: MockArtifacts(),
+        processManager: FakeProcessManager.any(),
+        fileSystem: globals.fs,
+        logger: globals.logger,
       );
       globals.fs.file('bin/cache/artifacts/engine/linux-x64/unrelated-stuff').createSync(recursive: true);
       globals.fs.file('bin/cache/artifacts/engine/linux-x64/libflutter_linux_glfw.so').createSync(recursive: true);
@@ -105,3 +116,4 @@ void main() {
 }
 
 class MockPlatform extends Mock implements Platform {}
+class MockArtifacts extends Mock implements Artifacts {}

packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/build.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/io.dart';
@@ -16,6 +17,7 @@ import 'package:process/process.dart';
 import 'package:platform/platform.dart';
 
 import '../../../src/common.dart';
+import '../../../src/fake_process_manager.dart';
 import '../../../src/testbed.dart';
 
 const String _kInputPrefix = 'bin/cache/artifacts/engine/darwin-x64/FlutterMacOS.framework';
@@ -70,8 +72,12 @@ void main() {
       defines: <String, String>{
           kBuildMode: 'debug',
           kTargetPlatform: 'darwin-x64',
-        },
-      );
+      },
+      artifacts: MockArtifacts(),
+      processManager: FakeProcessManager.any(),
+      logger: globals.logger,
+      fileSystem: globals.fs,
+    );
     }, overrides: <Type, Generator>{
       ProcessManager: () => MockProcessManager(),
       Platform: () => mockPlatform,
@@ -195,6 +201,7 @@ class MockPlatform extends Mock implements Platform {}
 class MockProcessManager extends Mock implements ProcessManager {}
 class MockGenSnapshot extends Mock implements GenSnapshot {}
 class MockXcode extends Mock implements Xcode {}
+class MockArtifacts extends Mock implements Artifacts {}
 class FakeProcessResult implements ProcessResult {
   @override
   int exitCode;

packages/flutter_tools/test/general.shard/build_system/targets/web_test.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:file_testing/file_testing.dart';
+import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 
 import 'package:flutter_tools/src/build_system/build_system.dart';
@@ -55,7 +56,11 @@ void main() {
         outputDir: globals.fs.currentDirectory.childDirectory('bar'),
         defines: <String, String>{
           kTargetFile: globals.fs.path.join('foo', 'lib', 'main.dart'),
-        }
+        },
+        artifacts: MockArtifacts(),
+        processManager: FakeProcessManager.any(),
+        logger: globals.logger,
+        fileSystem: globals.fs,
       );
       depfileService = DepfileService(
       fileSystem: globals.fs,
@@ -460,3 +465,4 @@ void main() {
 }
 
 class MockProcessManager extends Mock implements ProcessManager {}
+class MockArtifacts extends Mock implements Artifacts {}

packages/flutter_tools/test/general.shard/build_system/targets/windows_test.dart

@@ -3,102 +3,77 @@
 // found in the LICENSE file.
 
 import 'package:file/memory.dart';
+import 'package:file_testing/file_testing.dart';
+import 'package:flutter_tools/src/artifacts.dart';
+import 'package:flutter_tools/src/base/logger.dart';
+import 'package:mockito/mockito.dart';
+import 'package:platform/platform.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
-
 import 'package:flutter_tools/src/build_system/build_system.dart';
 import 'package:flutter_tools/src/build_system/targets/windows.dart';
-import 'package:flutter_tools/src/cache.dart';
-import 'package:flutter_tools/src/globals.dart' as globals;
-import 'package:mockito/mockito.dart';
-import 'package:platform/platform.dart';
 
 import '../../../src/common.dart';
 import '../../../src/fake_process_manager.dart';
-import '../../../src/testbed.dart';
+
+final Platform kWindowsPlatform = FakePlatform(
+  operatingSystem: 'windows',
+  environment: <String, String>{},
+);
+
+const List<String> kRequiredFiles = <String>[
+  r'C:\bin\cache\artifacts\engine\windows-x64\flutter_export.h',
+  r'C:\bin\cache\artifacts\engine\windows-x64\flutter_messenger.h',
+  r'C:\bin\cache\artifacts\engine\windows-x64\flutter_windows.dll',
+  r'C:\bin\cache\artifacts\engine\windows-x64\flutter_windows.dll.exp',
+  r'C:\bin\cache\artifacts\engine\windows-x64\flutter_windows.dll.lib',
+  r'C:\bin\cache\artifacts\engine\windows-x64\flutter_windows.dll.pdb',
+  r'C:\bin\cache\artifacts\engine\windows-x64\lutter_export.h',
+  r'C:\bin\cache\artifacts\engine\windows-x64\flutter_messenger.h',
+  r'C:\bin\cache\artifacts\engine\windows-x64\flutter_plugin_registrar.h',
+  r'C:\bin\cache\artifacts\engine\windows-x64\flutter_windows.h',
+  r'C:\bin\cache\artifacts\engine\windows-x64\icudtl.dat',
+  r'C:\bin\cache\artifacts\engine\windows-x64\cpp_client_wrapper\foo',
+  r'C:\packages\flutter_tools\lib\src\build_system\targets\windows.dart',
+];
 
 void main() {
-  Testbed testbed;
-  const BuildSystem buildSystem = BuildSystem();
   Environment environment;
-  Platform platform;
-
-  setUpAll(() {
-    Cache.disableLocking();
-    Cache.flutterRoot = '';
-  });
+  FileSystem fileSystem;
 
   setUp(() {
-    platform = MockPlatform();
-    when(platform.isWindows).thenReturn(true);
-    when(platform.isMacOS).thenReturn(false);
-    when(platform.isLinux).thenReturn(false);
-    when(platform.pathSeparator).thenReturn(r'\');
-    testbed = Testbed(setup: () {
-      environment = Environment.test(
-        globals.fs.currentDirectory,
-      );
-      globals.fs.file(r'C:\bin\cache\artifacts\engine\windows-x64\flutter_export.h').createSync(recursive: true);
-      globals.fs.file(r'C:\bin\cache\artifacts\engine\windows-x64\flutter_messenger.h').createSync();
-      globals.fs.file(r'C:\bin\cache\artifacts\engine\windows-x64\flutter_windows.dll').createSync();
-      globals.fs.file(r'C:\bin\cache\artifacts\engine\windows-x64\flutter_windows.dll.exp').createSync();
-      globals.fs.file(r'C:\bin\cache\artifacts\engine\windows-x64\flutter_windows.dll.lib').createSync();
-      globals.fs.file(r'C:\bin\cache\artifacts\engine\windows-x64\flutter_windows.dll.pdb').createSync();
-      globals.fs.file(r'C:\bin\cache\artifacts\engine\windows-x64\lutter_export.h').createSync();
-      globals.fs.file(r'C:\bin\cache\artifacts\engine\windows-x64\flutter_messenger.h').createSync();
-      globals.fs.file(r'C:\bin\cache\artifacts\engine\windows-x64\flutter_plugin_registrar.h').createSync();
-      globals.fs.file(r'C:\bin\cache\artifacts\engine\windows-x64\flutter_windows.h').createSync();
-      globals.fs.file(r'C:\bin\cache\artifacts\engine\windows-x64\icudtl.dat').createSync();
-      globals.fs.file(r'C:\bin\cache\artifacts\engine\windows-x64\cpp_client_wrapper\foo').createSync(recursive: true);
-      globals.fs.file(r'C:\packages\flutter_tools\lib\src\build_system\targets\windows.dart').createSync(recursive: true);
-      globals.fs.directory('windows').createSync();
-    }, overrides: <Type, Generator>{
-      FileSystem: () => MemoryFileSystem(style: FileSystemStyle.windows),
-      ProcessManager: () => FakeProcessManager.any(),
-      Platform: () => platform,
-    });
+    final MockArtifacts artifacts = MockArtifacts();
+    when(artifacts.getArtifactPath(Artifact.windowsDesktopPath))
+      .thenReturn(r'C:\bin\cache\artifacts\engine\windows-x64\');
+    fileSystem = MemoryFileSystem.test(style: FileSystemStyle.windows);
+    environment = Environment.test(
+      fileSystem.currentDirectory,
+      artifacts: artifacts,
+      processManager: FakeProcessManager.any(),
+      fileSystem: fileSystem,
+      logger: BufferLogger.test(),
+    );
+    for (final String path in kRequiredFiles) {
+      fileSystem.file(path).createSync(recursive: true);
+    }
+    fileSystem.directory('windows').createSync();
   });
 
-  test('Copies files to correct cache directory', () => testbed.run(() async {
-    await buildSystem.build(const UnpackWindows(), environment);
-
-    expect(globals.fs.file(r'C:\windows\flutter\flutter_export.h').existsSync(), true);
-    expect(globals.fs.file(r'C:\windows\flutter\flutter_messenger.h').existsSync(), true);
-    expect(globals.fs.file(r'C:\windows\flutter\flutter_windows.dll').existsSync(), true);
-    expect(globals.fs.file(r'C:\windows\flutter\flutter_windows.dll.exp').existsSync(), true);
-    expect(globals.fs.file(r'C:\windows\flutter\flutter_windows.dll.lib').existsSync(), true);
-    expect(globals.fs.file(r'C:\windows\flutter\flutter_windows.dll.pdb').existsSync(), true);
-    expect(globals.fs.file(r'C:\windows\flutter\flutter_export.h').existsSync(), true);
-    expect(globals.fs.file(r'C:\windows\flutter\flutter_messenger.h').existsSync(), true);
-    expect(globals.fs.file(r'C:\windows\flutter\flutter_plugin_registrar.h').existsSync(), true);
-    expect(globals.fs.file(r'C:\windows\flutter\flutter_windows.h').existsSync(), true);
-    expect(globals.fs.file(r'C:\windows\flutter\icudtl.dat').existsSync(), true);
-    expect(globals.fs.file(r'C:\windows\flutter\cpp_client_wrapper\foo').existsSync(), true);
-  }));
-
-  test('Does not re-copy files unecessarily', () => testbed.run(() async {
-    await buildSystem.build(const UnpackWindows(), environment);
-    // Set a date in the far distant past to deal with the limited resolution
-    // of the windows filesystem.
-    final DateTime theDistantPast = DateTime(1991, 8, 23);
-    globals.fs.file(r'C:\windows\flutter\flutter_export.h').setLastModifiedSync(theDistantPast);
-    await buildSystem.build(const UnpackWindows(), environment);
-
-    expect(globals.fs.file(r'C:\windows\flutter\flutter_export.h').statSync().modified, equals(theDistantPast));
-  }));
+  testWithoutContext('UnpackWindows copies files to the correct cache directory', () async {
+    await const UnpackWindows().build(environment);
 
-  test('Detects changes in input cache files', () => testbed.run(() async {
-    await buildSystem.build(const UnpackWindows(), environment);
-    // Set a date in the far distant past to deal with the limited resolution
-    // of the windows filesystem.
-    final DateTime theDistantPast = DateTime(1991, 8, 23);
-    globals.fs.file(r'C:\windows\flutter\flutter_export.h').setLastModifiedSync(theDistantPast);
-    final DateTime modified = globals.fs.file(r'C:\windows\flutter\flutter_export.h').statSync().modified;
-    globals.fs.file(r'C:\bin\cache\artifacts\engine\windows-x64\flutter_export.h').writeAsStringSync('asd'); // modify cache.
-
-    await buildSystem.build(const UnpackWindows(), environment);
-
-    expect(globals.fs.file(r'C:\windows\flutter\flutter_export.h').statSync().modified, isNot(modified));
-  }));
+    expect(fileSystem.file(r'C:\windows\flutter\flutter_export.h'), exists);
+    expect(fileSystem.file(r'C:\windows\flutter\flutter_messenger.h'), exists);
+    expect(fileSystem.file(r'C:\windows\flutter\flutter_windows.dll'), exists);
+    expect(fileSystem.file(r'C:\windows\flutter\flutter_windows.dll.exp'), exists);
+    expect(fileSystem.file(r'C:\windows\flutter\flutter_windows.dll.lib'), exists);
+    expect(fileSystem.file(r'C:\windows\flutter\flutter_windows.dll.pdb'), exists);
+    expect(fileSystem.file(r'C:\windows\flutter\flutter_export.h'), exists);
+    expect(fileSystem.file(r'C:\windows\flutter\flutter_messenger.h'), exists);
+    expect(fileSystem.file(r'C:\windows\flutter\flutter_plugin_registrar.h'), exists);
+    expect(fileSystem.file(r'C:\windows\flutter\flutter_windows.h'), exists);
+    expect(fileSystem.file(r'C:\windows\flutter\icudtl.dat'), exists);
+    expect(fileSystem.file(r'C:\windows\flutter\cpp_client_wrapper\foo'), exists);
+  });
 }
 
-class MockPlatform extends Mock implements Platform {}
+class MockArtifacts extends Mock implements Artifacts {}