Reactivate coverage tracking for dartdoc via coveralls (#1869)

* First try at enabling coveralls again for dartdoc

* dartfmt

* syntax error in travis.sh

* add quotes

* Fix coverage runner

* coveralls installation problem fix?

* coveralls is named coveralls

* Use relative package paths and otherwise fix up the format run

* Set up DART_VERSION correctly

* Work around dart-lang/coverage#239

* Don't try to run coverage on sdk-analyzer passes

* Add workarounds for bugs

* Drop almost everything from travis config to try to speed this up

* use packages flag instead of package-root

* Revert test code / travis changes

* dartfmt

* fix merge problem: flutter goes first

Author: jcollins-g

.gitignore

@@ -8,6 +8,7 @@
 .settings/
 build/
 doc/
+lcov.info
 packages
 pub.dartlang.org/
 testing/test_package/doc

README.md

@@ -1,6 +1,8 @@
 # dartdoc
 
 [![Build Status](https://travis-ci.org/dart-lang/dartdoc.svg?branch=master)](https://travis-ci.org/dart-lang/dartdoc)
+[![Coverage Status](https://coveralls.io/repos/github/dart-lang/dartdoc/badge.svg?branch=master)](https://coveralls.io/github/dart-lang/dartdoc?branch=master)
+
 
 Use `dartdoc` to generate HTML documentaton for your Dart package.
 

bin/dartdoc.dart

@@ -38,7 +38,7 @@ Future<List<DartdocOption>> createDartdocProgramOptions() async {
 
 /// Analyzes Dart files and generates a representation of included libraries,
 /// classes, and members. Uses the current directory to look for libraries.
-void main(List<String> arguments) async {
+Future<void> main(List<String> arguments) async {
   DartdocOptionSet optionSet =
       await DartdocOptionSet.fromOptionGenerators('dartdoc', [
     createDartdocOptions,
@@ -52,17 +52,27 @@ void main(List<String> arguments) async {
   } on FormatException catch (e) {
     stderr.writeln(' fatal error: ${e.message}');
     stderr.writeln('');
-    _printUsageAndExit(optionSet.argParser, exitCode: 64);
+    _printUsage(optionSet.argParser);
+    // Do not use exit() as this bypasses --pause-isolates-on-exit
+    // TODO(jcollins-g): use exit once dart-lang/sdk#31747 is fixed.
+    exitCode = 64;
+    return;
   } on DartdocOptionError catch (e) {
     stderr.writeln(' fatal error: ${e.message}');
     stderr.writeln('');
-    _printUsageAndExit(optionSet.argParser, exitCode: 64);
+    _printUsage(optionSet.argParser);
+    exitCode = 64;
+    return;
   }
   if (optionSet['help'].valueAt(Directory.current)) {
-    _printHelpAndExit(optionSet.argParser);
+    _printHelp(optionSet.argParser);
+    exitCode = 0;
+    return;
   }
   if (optionSet['version'].valueAt(Directory.current)) {
-    _printVersionAndExit(optionSet.argParser);
+    _printVersion(optionSet.argParser);
+    exitCode = 0;
+    return;
   }
 
   DartdocProgramOptionContext config =
@@ -88,34 +98,37 @@ void main(List<String> arguments) async {
     }, onError: (e, Chain chain) {
       if (e is DartdocFailure) {
         stderr.writeln('\nGeneration failed: ${e}.');
-        exit(1);
+        exitCode = 1;
+        return;
       } else {
         stderr.writeln('\nGeneration failed: ${e}\n${chain.terse}');
-        exit(255);
+        exitCode = 255;
+        return;
       }
     }, when: config.asyncStackTraces);
   } finally {
     // Clear out any cached tool snapshots and temporary directories.
+    // ignore: unawaited_futures
     SnapshotCache.instance.dispose();
+    // ignore: unawaited_futures
     ToolTempFileTracker.instance.dispose();
   }
+  exitCode = 0;
+  return;
 }
 
 /// Print help if we are passed the help option.
-void _printHelpAndExit(ArgParser parser, {int exitCode: 0}) {
+void _printHelp(ArgParser parser) {
   print('Generate HTML documentation for Dart libraries.\n');
-  _printUsageAndExit(parser, exitCode: exitCode);
 }
 
 /// Print usage information on invalid command lines.
-void _printUsageAndExit(ArgParser parser, {int exitCode: 0}) {
+void _printUsage(ArgParser parser) {
   print('Usage: dartdoc [OPTIONS]\n');
   print(parser.usage);
-  exit(exitCode);
 }
 
 /// Print version information.
-void _printVersionAndExit(ArgParser parser) {
+void _printVersion(ArgParser parser) {
   print('dartdoc version: ${dartdocVersion}');
-  exit(exitCode);
 }

lib/src/io_utils.dart

@@ -9,6 +9,7 @@ import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
+import 'package:dartdoc/src/tuple.dart';
 import 'package:path/path.dart' as pathLib;
 
 /// Return a resolved path including the home directory in place of tilde
@@ -116,6 +117,88 @@ class MultiFutureTracker<T> {
   Future<void> wait() async => await _waitUntil(0);
 }
 
+/// Keeps track of coverage data automatically for any processes run by this
+/// [CoverageSubprocessLauncher].  Requires that these be dart processes.
+class CoverageSubprocessLauncher extends SubprocessLauncher {
+  CoverageSubprocessLauncher(String context, [Map<String, String> environment])
+      : super(context, environment);
+
+  static int nextObservatoryPort = 9292;
+
+  /// Set this to true to enable coverage runs.
+  static bool coverageEnabled = false;
+
+  /// A list of all coverage results picked up by all launchers.
+  static List<Tuple2<String, Future<Iterable<Map>>>> coverageResults = [];
+
+  static Directory _tempDir;
+  static Directory get tempDir =>
+      _tempDir ??= Directory.systemTemp.createTempSync('dartdoc_coverage_data');
+
+  int _observatoryPort;
+  // TODO(jcollins-g): use ephemeral ports
+  int get observatoryPort => _observatoryPort ??= nextObservatoryPort++;
+
+  String _outCoverageFilename;
+  String get outCoverageFilename => _outCoverageFilename ??=
+      pathLib.join(tempDir.path, 'dart-cov-0-${observatoryPort}.json');
+
+  /// Call once all coverage runs have been generated by calling runStreamed
+  /// on all [CoverageSubprocessLaunchers].
+  static Future<void> generateCoverageToFile(File outputFile) async {
+    if (!coverageEnabled) return Future.value(null);
+    var currentCoverageResults = coverageResults;
+    coverageResults = [];
+    var launcher = SubprocessLauncher('format_coverage');
+
+    /// Wait for all coverage runs to finish.
+    await Future.wait(currentCoverageResults.map((t) => t.item2));
+
+    return launcher.runStreamed(Platform.executable, [
+      'tool/format_coverage.dart', // TODO(jcollins-g): use pub after dart-lang/coverage#240 is landed
+      '--lcov',
+      '-v',
+      '-b', '.',
+      '--packages=.packages',
+      '--sdk-root=${pathLib.canonicalize(pathLib.join(pathLib.dirname(Platform.executable), '..'))}',
+      '--out=${pathLib.canonicalize(outputFile.path)}',
+      '--report-on=bin,lib',
+      '-i', tempDir.path,
+    ]);
+  }
+
+  @override
+  Future<Iterable<Map>> runStreamed(String executable, List<String> arguments,
+      {String workingDirectory}) {
+    assert(executable == Platform.executable,
+        'Must use dart executable for tracking coverage');
+
+    if (coverageEnabled) {
+      arguments = [
+        '--enable-vm-service=${observatoryPort}',
+        '--pause-isolates-on-exit'
+      ]..addAll(arguments);
+    }
+
+    Future<Iterable<Map>> results = super
+        .runStreamed(executable, arguments, workingDirectory: workingDirectory);
+
+    if (coverageEnabled) {
+      coverageResults.add(new Tuple2(
+          outCoverageFilename,
+          super.runStreamed('pub', [
+            'run',
+            'coverage:collect_coverage',
+            '--wait-paused',
+            '--resume-isolates',
+            '--port=${observatoryPort}',
+            '--out=${outCoverageFilename}',
+          ])));
+    }
+    return results;
+  }
+}
+
 class SubprocessLauncher {
   final String context;
   final Map<String, String> environment;

pubspec.yaml

@@ -34,6 +34,7 @@ dev_dependencies:
   build: ^1.0.1
   build_runner: ^1.0.0
   build_version: ^1.0.0
+  coverage: any
   dhttpd: ^3.0.0
   glob: ^1.1.5
   grinder: ^0.8.2