Validate build_web_compilers, Exception handling

analysis_options.yaml

@@ -8,45 +8,66 @@ analyzer:
     override_on_non_overriding_method: error
 linter:
   rules:
-    # Errors
-    - avoid_empty_else
-    - await_only_futures
-    - comment_references
-    - control_flow_in_finally
-    - empty_statements
-    - hash_and_equals
-    - iterable_contains_unrelated_type
-    - no_duplicate_case_values
-    - test_types_in_equals
-    - throw_in_finally
-    - unawaited_futures
-    - unnecessary_statements
-    - unrelated_type_equality_checks
-    - valid_regexps
-
-    # Style
     - annotate_overrides
+    - avoid_empty_else
     - avoid_function_literals_in_foreach_calls
     - avoid_init_to_null
+    - avoid_null_checks_in_equality_operators
     - avoid_return_types_on_setters
     - avoid_returning_null
     - avoid_unused_constructor_parameters
+    - await_only_futures
     - camel_case_types
+    - cancel_subscriptions
+    #- cascade_invocations
+    - comment_references
+    - constant_identifier_names
+    - control_flow_in_finally
     - directives_ordering
     - empty_catches
     - empty_constructor_bodies
+    - empty_statements
+    - hash_and_equals
+    - implementation_imports
+    - invariant_booleans
+    - iterable_contains_unrelated_type
     - library_names
     - library_prefixes
+    - list_remove_unrelated_type
+    - no_adjacent_strings_in_list
+    - no_duplicate_case_values
     - non_constant_identifier_names
+    - omit_local_variable_types
+    - only_throw_errors
+    - overridden_fields
+    - package_api_docs
+    - package_names
+    - package_prefixed_library_names
+    - prefer_adjacent_string_concatenation
+    - prefer_collection_literals
     - prefer_conditional_assignment
+    - prefer_const_constructors
+    - prefer_contains
     - prefer_final_fields
+    #- prefer_final_locals
+    - prefer_initializing_formals
+    - prefer_interpolation_to_compose_strings
     - prefer_is_empty
     - prefer_is_not_empty
+    - prefer_single_quotes
     - prefer_typing_uninitialized_variables
     - recursive_getters
     - slash_for_doc_comments
+    - super_goes_last
+    - test_types_in_equals
+    - throw_in_finally
     - type_init_formals
+    - unawaited_futures
     - unnecessary_brace_in_string_interps
     - unnecessary_getters_setters
     - unnecessary_lambdas
     - unnecessary_null_aware_assignments
+    - unnecessary_statements
+    - unnecessary_this
+    - unrelated_type_equality_checks
+    - valid_regexps

webdev/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.1.1
+
+- Checks for a dependency on `build_web_compilers`.
+- Gracefully handle exceptions.
+
 ## 0.1.0
 
 - Initial release. Supports basic invocation of `build` and `serve` with

webdev/bin/webdev.dart

@@ -4,6 +4,7 @@
 
 import 'dart:async';
 import 'dart:io';
+import 'dart:isolate';
 
 import 'package:args/command_runner.dart';
 import 'package:io/ansi.dart';
@@ -28,5 +29,16 @@ Future main(List<String> args) async {
     }
 
     exitCode = ExitCode.config.code;
+  } on FileSystemException catch (e) {
+    print(yellow.wrap('Could not run in the current directory.'));
+    print(e.message);
+    if (e.path != null) {
+      print('  ${e.path}');
+    }
+    exitCode = ExitCode.config.code;
+  } on IsolateSpawnException catch (e) {
+    print(red.wrap('An unexpected exception has occurred.'));
+    print(e.message);
+    exitCode = ExitCode.software.code;
   }
 }

webdev/lib/src/command/build_runner_command_base.dart

@@ -11,6 +11,8 @@ import 'package:stack_trace/stack_trace.dart';
 
 import '../pubspec.dart';
 
+const _packagesFileName = '.packages';
+
 /// Extend to get a command with the arguments common to all build_runner
 /// commands.
 abstract class BuildRunnerCommandBase extends Command<int> {
@@ -30,6 +32,8 @@ abstract class BuildRunnerCommandBase extends Command<int> {
   Future<int> runCore(String command) async {
     await checkPubspecLock();
 
+    var buildRunnerScript = await _buildRunnerScript();
+
     final arguments = [command]..addAll(argResults.arguments);
 
     var exitCode = 0;
@@ -49,68 +53,87 @@ abstract class BuildRunnerCommandBase extends Command<int> {
       stderr.writeln(new Trace.parse(trace).terse);
       if (exitCode == 0) exitCode = 1;
     });
-    await Isolate.spawnUri(
-        await _buildRunnerScript(), arguments, messagePort.sendPort,
-        onExit: exitPort.sendPort,
-        onError: errorPort.sendPort,
-        automaticPackageResolution: true);
-    StreamSubscription exitCodeListener;
-    exitCodeListener = messagePort.listen((isolateExitCode) {
-      if (isolateExitCode is! int) {
-        throw new StateError(
-            'Bad response from isolate, expected an exit code but got '
-            '$isolateExitCode');
-      }
-      exitCode = isolateExitCode as int;
-      exitCodeListener.cancel();
-      exitCodeListener = null;
-    });
-    await exitPort.first;
-    await errorListener.cancel();
-    await exitCodeListener?.cancel();
 
-    return exitCode;
+    try {
+      await Isolate.spawnUri(buildRunnerScript, arguments, messagePort.sendPort,
+          onExit: exitPort.sendPort,
+          onError: errorPort.sendPort,
+          automaticPackageResolution: true);
+      StreamSubscription exitCodeListener;
+      exitCodeListener = messagePort.listen((isolateExitCode) {
+        if (isolateExitCode is! int) {
+          throw new StateError(
+              'Bad response from isolate, expected an exit code but got '
+              '$isolateExitCode');
+        }
+        exitCode = isolateExitCode as int;
+        exitCodeListener.cancel();
+        exitCodeListener = null;
+      });
+      await exitPort.first;
+      await errorListener.cancel();
+      await exitCodeListener?.cancel();
+
+      return exitCode;
+    } finally {
+      exitPort.close();
+      errorPort.close();
+      messagePort.close();
+    }
   }
 }
 
 Future<Uri> _buildRunnerScript() async {
+  var packagesFile = new File(_packagesFileName);
+  if (!packagesFile.existsSync()) {
+    throw new FileSystemException(
+        'A `$_packagesFileName` file does not exist in the target directory.',
+        packagesFile.absolute.path);
+  }
+
   var dataUri = new Uri.dataFromString(_bootstrapScript);
 
   var messagePort = new ReceivePort();
   var exitPort = new ReceivePort();
   var errorPort = new ReceivePort();
 
-  await Isolate.spawnUri(dataUri, [], messagePort.sendPort,
-      onExit: exitPort.sendPort,
-      onError: errorPort.sendPort,
-      errorsAreFatal: true,
-      packageConfig: new Uri.file('.packages'));
-
-  var allErrorsFuture = errorPort.forEach((error) {
-    var errorList = error as List;
-    var message = errorList[0] as String;
-    var stack = new StackTrace.fromString(errorList[1] as String);
-
-    stderr.writeln(message);
-    stderr.writeln(stack);
-  });
-
-  var items = await Future.wait([
-    messagePort.toList(),
-    allErrorsFuture,
-    exitPort.first.whenComplete(() {
-      messagePort.close();
-      errorPort.close();
-    })
-  ]);
+  try {
+    await Isolate.spawnUri(dataUri, [], messagePort.sendPort,
+        onExit: exitPort.sendPort,
+        onError: errorPort.sendPort,
+        errorsAreFatal: true,
+        packageConfig: new Uri.file(_packagesFileName));
 
-  var messages = items[0] as List;
-  if (messages.isEmpty) {
-    throw new StateError('An error occurred while running booting.');
-  }
+    var allErrorsFuture = errorPort.forEach((error) {
+      var errorList = error as List;
+      var message = errorList[0] as String;
+      var stack = new StackTrace.fromString(errorList[1] as String);
+
+      stderr.writeln(message);
+      stderr.writeln(stack);
+    });
 
-  assert(messages.length == 1);
-  return new Uri.file(messages.single as String);
+    var items = await Future.wait([
+      messagePort.toList(),
+      allErrorsFuture,
+      exitPort.first.whenComplete(() {
+        messagePort.close();
+        errorPort.close();
+      })
+    ]);
+
+    var messages = items[0] as List;
+    if (messages.isEmpty) {
+      throw new StateError('An error occurred while bootstrapping.');
+    }
+
+    assert(messages.length == 1);
+    return new Uri.file(messages.single as String);
+  } finally {
+    messagePort.close();
+    exitPort.close();
+    errorPort.close();
+  }
 }
 
 const _bootstrapScript = r'''

webdev/lib/src/pubspec.dart

@@ -33,6 +33,12 @@ class PackageExceptionDetails {
           'You must have a dependency on `build_runner` in `pubspec.yaml`. '
           'It can be in either `dependencies` or `dev_dependencies`.');
 
+  static const noBuildWebCompilersDep = const PackageExceptionDetails._(
+      'A dependency on `build_web_compilers` was not found.',
+      description:
+          'You must have a dependency on `build_web_compilers` in `pubspec.yaml` '
+          'or transitively via another dependency.');
+
   @override
   String toString() => [error, description].join('\n');
 }
@@ -81,8 +87,10 @@ Future checkPubspecLock() async {
     }
   }
 
-  // TODO: validate build_web_compilers
-  //var buldWebCompilers = packages['build_web_compilers'];
+  var buldWebCompilers = packages['build_web_compilers'];
+  if (buldWebCompilers == null) {
+    issues.add(PackageExceptionDetails.noBuildWebCompilersDep);
+  }
 
   if (issues.isNotEmpty) {
     throw new PackageException._(issues);

webdev/pubspec.yaml

@@ -1,5 +1,5 @@
 name: webdev
-version: 0.1.0
+version: 0.1.1-dev
 author: Dart Team <misc@dartlang.org>
 homepage: https://github.com/dart-lang/webdev
 description: >-