Exit resident web runner on initial compilation failure (#41441)

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

@@ -192,9 +192,7 @@ class ResidentWebRunner extends ResidentRunner {
         _connectionResult = await _webFs.connect(debuggingOptions);
         unawaited(_connectionResult.debugConnection.onDone.whenComplete(exit));
       }
-    } catch (err, stackTrace) {
-      printError(err.toString());
-      printError(stackTrace.toString());
+    } catch (err) {
       throwToolExit('Failed to build application for the web.');
     } finally {
       buildStatus.stop();

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

@@ -135,7 +135,7 @@ class WebFs {
     _client.startBuild();
     await for (BuildResults results in _client.buildResults) {
       final BuildResult result = results.results.firstWhere((BuildResult result) {
-        return result.target == 'web';
+        return result.target == kBuildTargetName;
       });
       if (result.status == BuildStatus.failed) {
         return false;
@@ -164,6 +164,7 @@ class WebFs {
     final bool hasWebPlugins = findPlugins(flutterProject)
         .any((Plugin p) => p.platforms.containsKey(WebPlugin.kConfigKey));
     // Start the build daemon and run an initial build.
+    final Completer<bool> inititalBuild = Completer<bool>();
     final BuildDaemonClient client = await buildDaemonCreator
       .startBuildDaemon(fs.currentDirectory.path,
           release: buildInfo.isRelease,
@@ -178,6 +179,17 @@ class WebFs {
           return results.results
             .firstWhere((BuildResult result) => result.target == kBuildTargetName);
         });
+    client.buildResults.listen((BuildResults buildResults) {
+      final BuildResult result = buildResults.results.firstWhere((BuildResult result) {
+        return result.target == kBuildTargetName;
+      });
+      if (result.status == BuildStatus.failed) {
+        inititalBuild.complete(false);
+      }
+      if (result.status == BuildStatus.succeeded) {
+        inititalBuild.complete(true);
+      }
+    });
     final int daemonAssetPort = buildDaemonCreator.assetServerPort(fs.currentDirectory);
 
     // Initialize the asset bundle.
@@ -249,13 +261,17 @@ class WebFs {
     cascade = cascade.add(assetServer.handle);
     final HttpServer server = await httpMultiServerFactory(hostname ?? _kHostName, hostPort);
     shelf_io.serveRequests(server, cascade.handler);
-    return WebFs(
+    final WebFs webFS = WebFs(
       client,
       server,
       dwds,
       'http://$_kHostName:$hostPort/',
       assetServer,
     );
+    if (!await inititalBuild.future) {
+      throw Exception('Failed to compile for the web.');
+    }
+    return webFS;
   }
 }
 

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

@@ -4,6 +4,7 @@
 
 import 'package:build_daemon/client.dart';
 import 'package:build_daemon/data/build_status.dart';
+import 'package:built_collection/built_collection.dart';
 import 'package:dwds/dwds.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/os.dart';
@@ -49,7 +50,18 @@ void main() {
       return 1234;
     });
     when(mockBuildDaemonClient.buildResults).thenAnswer((Invocation _) {
-      return const Stream<BuildResults>.empty();
+      return Stream<BuildResults>.fromFuture(Future<BuildResults>.value(
+        BuildResults((BuildResultsBuilder builder) {
+          builder.results = ListBuilder<BuildResult>(
+            <BuildResult>[
+              DefaultBuildResult((DefaultBuildResultBuilder builder) {
+                builder.target = 'web';
+                builder.status = BuildStatus.succeeded;
+              })
+            ]
+          );
+        })
+      ));
     });
     when(mockBuildDaemonCreator.assetServerPort(any)).thenReturn(4321);
     testbed = Testbed(
@@ -141,6 +153,34 @@ void main() {
     expect(lastPort, 1234);
     expect(lastAddress, contains('foo'));
   }));
+
+  test('Throws exception if build fails', () => testbed.run(() async {
+    when(mockBuildDaemonClient.buildResults).thenAnswer((Invocation _) {
+      return Stream<BuildResults>.fromFuture(Future<BuildResults>.value(
+        BuildResults((BuildResultsBuilder builder) {
+          builder.results = ListBuilder<BuildResult>(
+            <BuildResult>[
+              DefaultBuildResult((DefaultBuildResultBuilder builder) {
+                builder.target = 'web';
+                builder.status = BuildStatus.failed;
+              })
+            ]
+          );
+        })
+      ));
+    });
+    final FlutterProject flutterProject = FlutterProject.current();
+
+    expect(WebFs.start(
+      skipDwds: false,
+      target: fs.path.join('lib', 'main.dart'),
+      buildInfo: BuildInfo.debug,
+      flutterProject: flutterProject,
+      initializePlatform: false,
+      hostname: 'foo',
+      port: '1234',
+    ), throwsA(isInstanceOf<Exception>()));
+  }));
 }
 
 class MockBuildDaemonCreator extends Mock implements BuildDaemonCreator {}