[flutter_tools] Update WebAssetServer to avoid context, fix tests (#60224)

WebAssetServer could fail if some of the global statics it depended on were initialized in a different order. Fix this by removing globals.

Delete dwds startup test that needs to spawn a real server.

packages/flutter_tools/lib/src/build_runner/devfs_web.dart

@@ -20,6 +20,7 @@ import '../base/common.dart';
 import '../base/file_system.dart';
 import '../base/io.dart';
 import '../base/net.dart';
+import '../base/platform.dart';
 import '../base/utils.dart';
 import '../build_info.dart';
 import '../bundle.dart';
@@ -173,7 +174,13 @@ class WebAssetServer implements AssetReader {
 
       // In release builds deploy a simpler proxy server.
       if (buildMode != BuildMode.debug) {
-        final ReleaseAssetServer releaseAssetServer = ReleaseAssetServer(entrypoint);
+        final ReleaseAssetServer releaseAssetServer = ReleaseAssetServer(
+          entrypoint,
+          fileSystem: globals.fs,
+          platform: globals.platform,
+          flutterRoot: Cache.flutterRoot,
+          webBuildDirectory: getWebBuildDirectory(),
+        );
         shelf.serveRequests(httpServer, releaseAssetServer.handle);
         return server;
       }
@@ -817,17 +824,31 @@ class WebDevFS implements DevFS {
 }
 
 class ReleaseAssetServer {
-  ReleaseAssetServer(this.entrypoint);
+  ReleaseAssetServer(this.entrypoint, {
+    @required FileSystem fileSystem,
+    @required String webBuildDirectory,
+    @required String flutterRoot,
+    @required Platform platform,
+  }) : _fileSystem = fileSystem,
+       _platform = platform,
+       _flutterRoot = flutterRoot,
+       _webBuildDirectory = webBuildDirectory,
+       _fileSystemUtils = FileSystemUtils(fileSystem: fileSystem, platform: platform);
 
   final Uri entrypoint;
+  final String _flutterRoot;
+  final String _webBuildDirectory;
+  final FileSystem _fileSystem;
+  final FileSystemUtils _fileSystemUtils;
+  final Platform _platform;
 
   // Locations where source files, assets, or source maps may be located.
-  final List<Uri> _searchPaths = <Uri>[
-    globals.fs.directory(getWebBuildDirectory()).uri,
-    globals.fs.directory(Cache.flutterRoot).uri,
-    globals.fs.directory(Cache.flutterRoot).parent.uri,
-    globals.fs.currentDirectory.uri,
-    globals.fs.directory(globals.fsUtils.homeDirPath).uri,
+  List<Uri> _searchPaths() => <Uri>[
+    _fileSystem.directory(_webBuildDirectory).uri,
+    _fileSystem.directory(_flutterRoot).uri,
+    _fileSystem.directory(_flutterRoot).parent.uri,
+    _fileSystem.currentDirectory.uri,
+    _fileSystem.directory(_fileSystemUtils.homeDirPath).uri,
   ];
 
   Future<shelf.Response> handle(shelf.Request request) async {
@@ -835,10 +856,10 @@ class ReleaseAssetServer {
     if (request.url.toString() == 'main.dart') {
       fileUri = entrypoint;
     } else {
-      for (final Uri uri in _searchPaths) {
+      for (final Uri uri in _searchPaths()) {
         final Uri potential = uri.resolve(request.url.path);
-        if (potential == null || !globals.fs.isFileSync(
-          potential.toFilePath(windows: globals.platform.isWindows))) {
+        if (potential == null || !_fileSystem.isFileSync(
+          potential.toFilePath(windows: _platform.isWindows))) {
           continue;
         }
         fileUri = potential;
@@ -846,7 +867,7 @@ class ReleaseAssetServer {
       }
     }
     if (fileUri != null) {
-      final File file = globals.fs.file(fileUri);
+      final File file = _fileSystem.file(fileUri);
       final Uint8List bytes = file.readAsBytesSync();
       // Fallback to "application/octet-stream" on null which
       // makes no claims as to the structure of the data.
@@ -857,7 +878,7 @@ class ReleaseAssetServer {
       });
     }
     if (request.url.path == '') {
-      final File file = globals.fs.file(globals.fs.path.join(getWebBuildDirectory(), 'index.html'));
+      final File file = _fileSystem.file(_fileSystem.path.join(_webBuildDirectory, 'index.html'));
       return shelf.Response.ok(file.readAsBytesSync(), headers: <String, String>{
         'Content-Type': 'text/html',
       });

packages/flutter_tools/test/general.shard/resident_runner_test.dart

@@ -93,7 +93,9 @@ void main() {
 
   setUp(() {
     testbed = Testbed(setup: () {
-      globals.fs.file(globalPackagesPath).writeAsStringSync('\n');
+      globals.fs.file(globalPackagesPath)
+        ..createSync(recursive: true)
+        ..writeAsStringSync('\n');
       globals.fs.file(globals.fs.path.join('build', 'app.dill'))
         ..createSync(recursive: true)
         ..writeAsStringSync('ABC');

packages/flutter_tools/test/general.shard/web/devfs_web_test.dart

@@ -2,14 +2,9 @@
 // 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:io';
 
-import 'package:dwds/data/build_result.dart';
 import 'package:dwds/dwds.dart';
-import 'package:dwds/src/loaders/strategy.dart';
-import 'package:dwds/src/readers/asset_reader.dart';
-import 'package:dwds/src/services/expression_compiler.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/io.dart';
 import 'package:flutter_tools/src/base/platform.dart';
@@ -18,7 +13,6 @@ import 'package:flutter_tools/src/build_runner/devfs_web.dart';
 import 'package:flutter_tools/src/compile.dart';
 import 'package:flutter_tools/src/convert.dart';
 import 'package:flutter_tools/src/globals.dart' as globals;
-import 'package:logging/logging.dart';
 import 'package:mockito/mockito.dart';
 import 'package:package_config/package_config.dart';
 import 'package:shelf/shelf.dart';
@@ -531,46 +525,6 @@ void main() {
     expect(uri, Uri.http('localhost:0', ''));
     await webDevFS.destroy();
   }));
-
-  test('Launches DWDS with the correct arguments', () => testbed.run(() async {
-    globals.fs.file('.packages').writeAsStringSync('\n');
-    final WebAssetServer server = await WebAssetServer.start(
-      null,
-      'any',
-      8123,
-      (String url) => null,
-      true,
-      BuildMode.debug,
-      true,
-      Uri.file('test.dart'),
-      null,
-      dwdsLauncher: ({
-        AssetReader assetReader,
-        Stream<BuildResult> buildResults,
-        ConnectionProvider chromeConnection,
-        bool enableDebugExtension,
-        bool enableDebugging,
-        ExpressionCompiler expressionCompiler,
-        String hostname,
-        LoadStrategy loadStrategy,
-        void Function(Level, String) logWriter,
-        bool serveDevTools,
-        UrlEncoder urlEncoder,
-        bool useSseForDebugProxy,
-        bool verbose,
-      }) async {
-        expect(serveDevTools, false);
-        expect(verbose, null);
-        expect(enableDebugging, true);
-        expect(enableDebugExtension, true);
-        expect(useSseForDebugProxy, true);
-        expect(hostname, 'any');
-
-        return MockDwds();
-      });
-
-    await server.dispose();
-  }));
 }
 
 class MockHttpServer extends Mock implements HttpServer {}

packages/flutter_tools/test/general.shard/web/web_asset_server_test.dart

@@ -10,7 +10,6 @@ import 'package:flutter_tools/src/build_runner/devfs_web.dart';
 import 'package:shelf/shelf.dart';
 
 import '../../src/common.dart';
-import '../../src/context.dart';
 
 const List<int> kTransparentImage = <int>[
   0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, 0x00, 0x00, 0x00, 0x0D, 0x49,
@@ -45,8 +44,13 @@ void main() {
       ..writeAsBytesSync(<int>[1, 2, 3]);
   });
 
-  testUsingContext('release asset server serves correct mime type and content length for png', () async {
-    final ReleaseAssetServer assetServer = ReleaseAssetServer(Uri.base);
+  testWithoutContext('release asset server serves correct mime type and content length for png', () async {
+    final ReleaseAssetServer assetServer = ReleaseAssetServer(Uri.base,
+      fileSystem: fileSystem,
+      platform: platform,
+      flutterRoot: '/flutter',
+      webBuildDirectory: 'build/web',
+    );
     fileSystem.file('build/web/assets/foo.png')
       ..createSync(recursive: true)
       ..writeAsBytesSync(kTransparentImage);
@@ -57,14 +61,15 @@ void main() {
       'Content-Type': 'image/png',
       'content-length': '64',
     });
-  }, overrides: <Type, Generator>{
-    FileSystem: () => fileSystem,
-    Platform: () => platform,
-    ProcessManager: () => FakeProcessManager.any(),
   });
 
-  testUsingContext('release asset server serves correct mime type and content length for JavaScript', () async {
-    final ReleaseAssetServer assetServer = ReleaseAssetServer(Uri.base);
+  testWithoutContext('release asset server serves correct mime type and content length for JavaScript', () async {
+    final ReleaseAssetServer assetServer = ReleaseAssetServer(Uri.base,
+      fileSystem: fileSystem,
+      platform: platform,
+      flutterRoot: '/flutter',
+      webBuildDirectory: 'build/web',
+    );
     fileSystem.file('build/web/assets/foo.js')
       ..createSync(recursive: true)
       ..writeAsStringSync('function main() {}');
@@ -75,14 +80,15 @@ void main() {
       'Content-Type': 'application/javascript',
       'content-length': '18',
     });
-  }, overrides: <Type, Generator>{
-    FileSystem: () => fileSystem,
-    Platform: () => platform,
-    ProcessManager: () => FakeProcessManager.any(),
   });
 
-  testUsingContext('release asset server serves correct mime type and content length for html', () async {
-    final ReleaseAssetServer assetServer = ReleaseAssetServer(Uri.base);
+  testWithoutContext('release asset server serves correct mime type and content length for html', () async {
+    final ReleaseAssetServer assetServer = ReleaseAssetServer(Uri.base,
+      fileSystem: fileSystem,
+      platform: platform,
+      flutterRoot: '/flutter',
+      webBuildDirectory: 'build/web',
+    );
     fileSystem.file('build/web/assets/foo.html')
       ..createSync(recursive: true)
       ..writeAsStringSync('<!doctype html><html></html>');
@@ -93,14 +99,15 @@ void main() {
       'Content-Type': 'text/html',
       'content-length': '28',
     });
-  }, overrides: <Type, Generator>{
-    FileSystem: () => fileSystem,
-    Platform: () => platform,
-    ProcessManager: () => FakeProcessManager.any(),
   });
 
-  testUsingContext('release asset server serves content from flutter root', () async {
-    final ReleaseAssetServer assetServer = ReleaseAssetServer(Uri.base);
+  testWithoutContext('release asset server serves content from flutter root', () async {
+    final ReleaseAssetServer assetServer = ReleaseAssetServer(Uri.base,
+      fileSystem: fileSystem,
+      platform: platform,
+      flutterRoot: '/flutter',
+      webBuildDirectory: 'build/web',
+    );
     fileSystem.file('flutter/bar.dart')
       ..createSync(recursive: true)
       ..writeAsStringSync('void main() { }');
@@ -108,14 +115,15 @@ void main() {
       .handle(Request('GET', Uri.parse('http://localhost:8080/flutter/bar.dart')));
 
     expect(response.statusCode, HttpStatus.ok);
-  }, overrides: <Type, Generator>{
-    FileSystem: () => fileSystem,
-    Platform: () => platform,
-    ProcessManager: () => FakeProcessManager.any(),
   });
 
-  testUsingContext('release asset server serves content from project directory', () async {
-    final ReleaseAssetServer assetServer = ReleaseAssetServer(Uri.base);
+  testWithoutContext('release asset server serves content from project directory', () async {
+    final ReleaseAssetServer assetServer = ReleaseAssetServer(Uri.base,
+      fileSystem: fileSystem,
+      platform: platform,
+      flutterRoot: '/flutter',
+      webBuildDirectory: 'build/web',
+    );
     fileSystem.file('bar.dart')
       ..createSync(recursive: true)
       ..writeAsStringSync('void main() { }');
@@ -123,9 +131,5 @@ void main() {
       .handle(Request('GET', Uri.parse('http://localhost:8080/bar.dart')));
 
     expect(response.statusCode, HttpStatus.ok);
-  }, overrides: <Type, Generator>{
-    FileSystem: () => fileSystem,
-    Platform: () => platform,
-    ProcessManager: () => FakeProcessManager.any(),
   });
 }