tools/gardening/compare_failures.dart - sdk.git - Git at Google

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 /// Compares the test log of a build step with previous builds.
 ///
 /// Use this to detect flakiness of failures, especially timeouts.

 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';

 main(List<String> args) async {
   if (args.length != 1) {
     print('Usage: compare_failures <log-uri>');
     exit(1);
   }
   String url = args.first;
   if (!url.endsWith('/text')) {
     // Use the text version of the stdio log.
     url += '/text';
   }
   Uri uri = Uri.parse(url);
   HttpClient client = new HttpClient();
   BuildUri buildUri = new BuildUri(uri);
   List<BuildResult> results = await readBuildResults(client, buildUri);
   print(generateBuildResultsSummary(buildUri, results));
   client.close();
 }

 /// Creates a [BuildResult] for [buildUri] and, if it contains failures, the
 /// [BuildResult]s for the previous 5 builds.
 Future<List<BuildResult>> readBuildResults(
     HttpClient client, BuildUri buildUri) async {
   List<BuildResult> summaries = <BuildResult>[];
   BuildResult firstSummary = await readBuildResult(client, buildUri);
   summaries.add(firstSummary);
   if (firstSummary.hasFailures) {
     for (int i = 0; i < 5; i++) {
       buildUri = buildUri.prev();
       summaries.add(await readBuildResult(client, buildUri));
     }
   }
   return summaries;
 }

 /// Reads the content of [uri] as text.
 Future<String> readUriAsText(HttpClient client, Uri uri) async {
   HttpClientRequest request = await client.getUrl(uri);
   HttpClientResponse response = await request.close();
   return UTF8.decode(await response.expand((l) => l).toList());
 }

 /// Parses the [buildUri] test log and creates a [BuildResult] for it.
 Future<BuildResult> readBuildResult(
     HttpClient client, BuildUri buildUri) async {
   Uri uri = buildUri.toUri();
   log('Reading $uri');
   String text = await readUriAsText(client, uri);

   bool inFailure = false;
   List<String> currentFailure;
   bool parsingTimingBlock = false;

   List<TestFailure> failures = <TestFailure>[];
   List<Timing> timings = <Timing>[];
   for (String line in text.split('\n')) {
     if (currentFailure != null) {
       if (line.startsWith('!@@@STEP_CLEAR@@@')) {
         failures.add(new TestFailure(buildUri, currentFailure));
         currentFailure = null;
       } else {
         currentFailure.add(line);
       }
     } else if (inFailure && line.startsWith('@@@STEP_FAILURE@@@')) {
       inFailure = false;
     } else if (line.startsWith('!@@@STEP_FAILURE@@@')) {
       inFailure = true;
     } else if (line.startsWith('FAILED:')) {
       currentFailure = <String>[];
       currentFailure.add(line);
     }
     if (line.startsWith('--- Total time:')) {
       parsingTimingBlock = true;
     } else if (parsingTimingBlock) {
       if (line.startsWith('0:')) {
         timings.addAll(parseTimings(buildUri, line));
       } else {
         parsingTimingBlock = false;
       }
     }
   }
   return new BuildResult(buildUri, failures, timings);
 }

 /// Generate a summary of the timeouts and other failures in [results].
 String generateBuildResultsSummary(
     BuildUri buildUri, List<BuildResult> results) {
   StringBuffer sb = new StringBuffer();
   sb.write('Results for $buildUri:\n');
   Set<TestConfiguration> timeoutIds = new Set<TestConfiguration>();
   for (BuildResult result in results) {
     timeoutIds.addAll(result.timeouts.map((TestFailure failure) => failure.id));
   }
   if (timeoutIds.isNotEmpty) {
     int firstBuildNumber = results.first.buildUri.buildNumber;
     int lastBuildNumber = results.last.buildUri.buildNumber;
     Map<TestConfiguration, Map<int, Map<String, Timing>>> map =
         <TestConfiguration, Map<int, Map<String, Timing>>>{};
     Set<String> stepNames = new Set<String>();
     for (BuildResult result in results) {
       for (Timing timing in result.timings) {
         Map<int, Map<String, Timing>> builds =
             map.putIfAbsent(timing.step.id, () => <int, Map<String, Timing>>{});
         stepNames.add(timing.step.stepName);
         builds.putIfAbsent(timing.uri.buildNumber, () => <String, Timing>{})[
             timing.step.stepName] = timing;
       }
     }
     sb.write('Timeouts for ${buildUri} :\n');
     map.forEach((TestConfiguration id, Map<int, Map<String, Timing>> timings) {
       if (!timeoutIds.contains(id)) return;
       sb.write('$id\n');
       sb.write(
           '${' ' * 8} ${stepNames.map((t) => padRight(t, 14)).join(' ')}\n');
       for (int buildNumber = firstBuildNumber;
           buildNumber >= lastBuildNumber;
           buildNumber--) {
         Map<String, Timing> steps = timings[buildNumber] ?? const {};
         sb.write(padRight(' ${buildNumber}: ', 8));
         for (String stepName in stepNames) {
           Timing timing = steps[stepName];
           if (timing != null) {
             sb.write(' ${timing.time}');
           } else {
             sb.write(' --------------');
           }
         }
         sb.write('\n');
       }
       sb.write('\n');
     });
   }
   Set<TestConfiguration> errorIds = new Set<TestConfiguration>();
   for (BuildResult result in results) {
     errorIds.addAll(result.errors.map((TestFailure failure) => failure.id));
   }
   if (errorIds.isNotEmpty) {
     int firstBuildNumber = results.first.buildUri.buildNumber;
     int lastBuildNumber = results.last.buildUri.buildNumber;
     Map<TestConfiguration, Map<int, TestFailure>> map =
         <TestConfiguration, Map<int, TestFailure>>{};
     for (BuildResult result in results) {
       for (TestFailure failure in result.errors) {
         map.putIfAbsent(failure.id, () => <int, TestFailure>{})[
             failure.uri.buildNumber] = failure;
       }
     }
     sb.write('Errors for ${buildUri} :\n');
     // TODO(johnniwinther): Improve comparison of non-timeouts.
     map.forEach((TestConfiguration id, Map<int, TestFailure> failures) {
       if (!errorIds.contains(id)) return;
       sb.write('$id\n');
       for (int buildNumber = firstBuildNumber;
           buildNumber >= lastBuildNumber;
           buildNumber--) {
         TestFailure failure = failures[buildNumber];
         sb.write(padRight(' ${buildNumber}: ', 8));
         if (failure != null) {
           sb.write(padRight(failure.expected, 10));
           sb.write(' / ');
           sb.write(padRight(failure.actual, 10));
         } else {
           sb.write(' ' * 10);
           sb.write(' / ');
           sb.write(padRight('-- OK --', 10));
         }
         sb.write('\n');
       }
       sb.write('\n');
     });
   }
   return sb.toString();
 }

 /// The results of a build step.
 class BuildResult {
   final BuildUri buildUri;
   final List<TestFailure> _failures;
   final List<Timing> _timings;

   BuildResult(this.buildUri, this._failures, this._timings);

   /// `true` of the build result has test failures.
   bool get hasFailures => _failures.isNotEmpty;

   /// Returns the top-20 timings found in the build log.
   Iterable<Timing> get timings => _timings;

   /// Returns the [TestFailure]s for tests that timed out.
   Iterable<TestFailure> get timeouts {
     return _failures
         .where((TestFailure failure) => failure.actual == 'Timeout');
   }

   /// Returns the [TestFailure]s for failing tests that did not time out.
   Iterable<TestFailure> get errors {
     return _failures
         .where((TestFailure failure) => failure.actual != 'Timeout');
   }

   String toString() {
     StringBuffer sb = new StringBuffer();
     sb.write('$buildUri\n');
     sb.write('Failures:\n${_failures.join('\n-----\n')}\n');
     sb.write('\nTimings:\n${_timings.join('\n')}');
     return sb.toString();
   }
 }

 /// The [Uri] of a build step stdio log split into its subparts.
 class BuildUri {
   final String scheme;
   final String host;
   final String prefix;
   final String botName;
   final int buildNumber;
   final String stepName;
   final String suffix;

   factory BuildUri(Uri uri) {
     String scheme = uri.scheme;
     String host = uri.host;
     List<String> parts =
         split(uri.path, ['/builders/', '/builds/', '/steps/', '/logs/']);
     String prefix = parts[0];
     String botName = parts[1];
     int buildNumber = int.parse(parts[2]);
     String stepName = parts[3];
     String suffix = parts[4];
     return new BuildUri.internal(
         scheme, host, prefix, botName, buildNumber, stepName, suffix);
   }

   BuildUri.internal(this.scheme, this.host, this.prefix, this.botName,
       this.buildNumber, this.stepName, this.suffix);

   String get buildName =>
       '/builders/$botName/builds/$buildNumber/steps/$stepName';

   String get path => '$prefix$buildName/logs/$suffix';

   /// Creates the [Uri] for this build step stdio log.
   Uri toUri() {
     return new Uri(scheme: scheme, host: host, path: path);
   }

   /// Returns the [BuildUri] the previous build of this build step.
   BuildUri prev() {
     return new BuildUri.internal(
         scheme, host, prefix, botName, buildNumber - 1, stepName, suffix);
   }

   String toString() {
     return buildName;
   }
 }

 /// Id for a test on a specific configuration, for instance
 /// `dart2js-chrome release_x64/co19/Language/Metadata/before_function_t07`.
 class TestConfiguration {
   final String configName;
   final String testName;

   TestConfiguration(this.configName, this.testName);

   String toString() {
     return '$configName $testName';
   }

   int get hashCode => configName.hashCode * 17 + testName.hashCode * 19;

   bool operator ==(other) {
     if (identical(this, other)) return true;
     if (other is! TestConfiguration) return false;
     return configName == other.configName && testName == other.testName;
   }
 }

 /// Test failure data derived from the test failure summary in the build step
 /// stdio log.
 class TestFailure {
   final BuildUri uri;
   final TestConfiguration id;
   final String expected;
   final String actual;
   final String text;

   factory TestFailure(BuildUri uri, List<String> lines) {
     List<String> parts = split(lines.first, ['FAILED: ', ' ', ' ']);
     String configName = parts[1];
     String archName = parts[2];
     String testName = parts[3];
     TestConfiguration id =
         new TestConfiguration(configName, '$archName/$testName');
     String expected = split(lines[1], ['Expected: '])[1];
     String actual = split(lines[2], ['Actual: '])[1];
     return new TestFailure.internal(
         uri, id, expected, actual, lines.skip(3).join('\n'));
   }

   TestFailure.internal(
       this.uri, this.id, this.expected, this.actual, this.text);

   String toString() {
     StringBuffer sb = new StringBuffer();
     sb.write('FAILED: $id\n');
     sb.write('Expected: $expected\n');
     sb.write('Actual: $actual\n');
     sb.write(text);
     return sb.toString();
   }
 }

 /// Id for a single test step, for instance the compilation and run steps of
 /// a test.
 class TestStep {
   final String stepName;
   final TestConfiguration id;

   TestStep(this.stepName, this.id);

   String toString() {
     return '$stepName - $id';
   }

   int get hashCode => stepName.hashCode * 13 + id.hashCode * 17;

   bool operator ==(other) {
     if (identical(this, other)) return true;
     if (other is! TestStep) return false;
     return stepName == other.stepName && id == other.id;
   }
 }

 /// The timing result for a single test step.
 class Timing {
   final BuildUri uri;
   final String time;
   final TestStep step;

   Timing(this.uri, this.time, this.step);

   String toString() {
     return '$time - $step';
   }
 }

 /// Create the [Timing]s for the [line] as found in the top-20 timings of a
 /// build step stdio log.
 List<Timing> parseTimings(BuildUri uri, String line) {
   List<String> parts = split(line, [' - ', ' - ', ' ']);
   String time = parts[0];
   String stepName = parts[1];
   String configName = parts[2];
   String testNames = parts[3];
   List<Timing> timings = <Timing>[];
   for (String testName in testNames.split(',')) {
     timings.add(new Timing(
         uri,
         time,
         new TestStep(
             stepName, new TestConfiguration(configName, testName.trim()))));
   }
   return timings;
 }

 /// Split [text] using [infixes] as infix markers.
 List<String> split(String text, List<String> infixes) {
   List<String> result = <String>[];
   int start = 0;
   for (String infix in infixes) {
     int index = text.indexOf(infix, start);
     if (index == -1)
       throw "'$infix' not found in '$text' from offset ${start}.";
     result.add(text.substring(start, index));
     start = index + infix.length;
   }
   result.add(text.substring(start));
   return result;
 }

 /// Pad [text] with spaces to the right to fit [length].
 String padRight(String text, int length) {
   if (text.length < length) return '${text}${' ' * (length - text.length)}';
   return text;
 }

 void log(String text) {
   print(text);
 }
	// Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	/// Compares the test log of a build step with previous builds.
	///
	/// Use this to detect flakiness of failures, especially timeouts.

	import 'dart:async';
	import 'dart:convert';
	import 'dart:io';

	main(List<String> args) async {
	if (args.length != 1) {
	print('Usage: compare_failures <log-uri>');
	exit(1);
	}
	String url = args.first;
	if (!url.endsWith('/text')) {
	// Use the text version of the stdio log.
	url += '/text';
	}
	Uri uri = Uri.parse(url);
	HttpClient client = new HttpClient();
	BuildUri buildUri = new BuildUri(uri);
	List<BuildResult> results = await readBuildResults(client, buildUri);
	print(generateBuildResultsSummary(buildUri, results));
	client.close();
	}

	/// Creates a [BuildResult] for [buildUri] and, if it contains failures, the
	/// [BuildResult]s for the previous 5 builds.
	Future<List<BuildResult>> readBuildResults(
	HttpClient client, BuildUri buildUri) async {
	List<BuildResult> summaries = <BuildResult>[];
	BuildResult firstSummary = await readBuildResult(client, buildUri);
	summaries.add(firstSummary);
	if (firstSummary.hasFailures) {
	for (int i = 0; i < 5; i++) {
	buildUri = buildUri.prev();
	summaries.add(await readBuildResult(client, buildUri));
	}
	}
	return summaries;
	}

	/// Reads the content of [uri] as text.
	Future<String> readUriAsText(HttpClient client, Uri uri) async {
	HttpClientRequest request = await client.getUrl(uri);
	HttpClientResponse response = await request.close();
	return UTF8.decode(await response.expand((l) => l).toList());
	}

	/// Parses the [buildUri] test log and creates a [BuildResult] for it.
	Future<BuildResult> readBuildResult(
	HttpClient client, BuildUri buildUri) async {
	Uri uri = buildUri.toUri();
	log('Reading $uri');
	String text = await readUriAsText(client, uri);

	bool inFailure = false;
	List<String> currentFailure;
	bool parsingTimingBlock = false;

	List<TestFailure> failures = <TestFailure>[];
	List<Timing> timings = <Timing>[];
	for (String line in text.split('\n')) {
	if (currentFailure != null) {
	if (line.startsWith('!@@@STEP_CLEAR@@@')) {
	failures.add(new TestFailure(buildUri, currentFailure));
	currentFailure = null;
	} else {
	currentFailure.add(line);
	}
	} else if (inFailure && line.startsWith('@@@STEP_FAILURE@@@')) {
	inFailure = false;
	} else if (line.startsWith('!@@@STEP_FAILURE@@@')) {
	inFailure = true;
	} else if (line.startsWith('FAILED:')) {
	currentFailure = <String>[];
	currentFailure.add(line);
	}
	if (line.startsWith('--- Total time:')) {
	parsingTimingBlock = true;
	} else if (parsingTimingBlock) {
	if (line.startsWith('0:')) {
	timings.addAll(parseTimings(buildUri, line));
	} else {
	parsingTimingBlock = false;
	}
	}
	}
	return new BuildResult(buildUri, failures, timings);
	}

	/// Generate a summary of the timeouts and other failures in [results].
	String generateBuildResultsSummary(
	BuildUri buildUri, List<BuildResult> results) {
	StringBuffer sb = new StringBuffer();
	sb.write('Results for $buildUri:\n');
	Set<TestConfiguration> timeoutIds = new Set<TestConfiguration>();
	for (BuildResult result in results) {
	timeoutIds.addAll(result.timeouts.map((TestFailure failure) => failure.id));
	}
	if (timeoutIds.isNotEmpty) {
	int firstBuildNumber = results.first.buildUri.buildNumber;
	int lastBuildNumber = results.last.buildUri.buildNumber;
	Map<TestConfiguration, Map<int, Map<String, Timing>>> map =
	<TestConfiguration, Map<int, Map<String, Timing>>>{};
	Set<String> stepNames = new Set<String>();
	for (BuildResult result in results) {
	for (Timing timing in result.timings) {
	Map<int, Map<String, Timing>> builds =
	map.putIfAbsent(timing.step.id, () => <int, Map<String, Timing>>{});
	stepNames.add(timing.step.stepName);
	builds.putIfAbsent(timing.uri.buildNumber, () => <String, Timing>{})[
	timing.step.stepName] = timing;
	}
	}
	sb.write('Timeouts for ${buildUri} :\n');
	map.forEach((TestConfiguration id, Map<int, Map<String, Timing>> timings) {
	if (!timeoutIds.contains(id)) return;
	sb.write('$id\n');
	sb.write(
	'${' ' * 8} ${stepNames.map((t) => padRight(t, 14)).join(' ')}\n');
	for (int buildNumber = firstBuildNumber;
	buildNumber >= lastBuildNumber;
	buildNumber--) {
	Map<String, Timing> steps = timings[buildNumber] ?? const {};
	sb.write(padRight(' ${buildNumber}: ', 8));
	for (String stepName in stepNames) {
	Timing timing = steps[stepName];
	if (timing != null) {
	sb.write(' ${timing.time}');
	} else {
	sb.write(' --------------');
	}
	}
	sb.write('\n');
	}
	sb.write('\n');
	});
	}
	Set<TestConfiguration> errorIds = new Set<TestConfiguration>();
	for (BuildResult result in results) {
	errorIds.addAll(result.errors.map((TestFailure failure) => failure.id));
	}
	if (errorIds.isNotEmpty) {
	int firstBuildNumber = results.first.buildUri.buildNumber;
	int lastBuildNumber = results.last.buildUri.buildNumber;
	Map<TestConfiguration, Map<int, TestFailure>> map =
	<TestConfiguration, Map<int, TestFailure>>{};
	for (BuildResult result in results) {
	for (TestFailure failure in result.errors) {
	map.putIfAbsent(failure.id, () => <int, TestFailure>{})[
	failure.uri.buildNumber] = failure;
	}
	}
	sb.write('Errors for ${buildUri} :\n');
	// TODO(johnniwinther): Improve comparison of non-timeouts.
	map.forEach((TestConfiguration id, Map<int, TestFailure> failures) {
	if (!errorIds.contains(id)) return;
	sb.write('$id\n');
	for (int buildNumber = firstBuildNumber;
	buildNumber >= lastBuildNumber;
	buildNumber--) {
	TestFailure failure = failures[buildNumber];
	sb.write(padRight(' ${buildNumber}: ', 8));
	if (failure != null) {
	sb.write(padRight(failure.expected, 10));
	sb.write(' / ');
	sb.write(padRight(failure.actual, 10));
	} else {
	sb.write(' ' * 10);
	sb.write(' / ');
	sb.write(padRight('-- OK --', 10));
	}
	sb.write('\n');
	}
	sb.write('\n');
	});
	}
	return sb.toString();
	}

	/// The results of a build step.
	class BuildResult {
	final BuildUri buildUri;
	final List<TestFailure> _failures;
	final List<Timing> _timings;

	BuildResult(this.buildUri, this._failures, this._timings);

	/// `true` of the build result has test failures.
	bool get hasFailures => _failures.isNotEmpty;

	/// Returns the top-20 timings found in the build log.
	Iterable<Timing> get timings => _timings;

	/// Returns the [TestFailure]s for tests that timed out.
	Iterable<TestFailure> get timeouts {
	return _failures
	.where((TestFailure failure) => failure.actual == 'Timeout');
	}

	/// Returns the [TestFailure]s for failing tests that did not time out.
	Iterable<TestFailure> get errors {
	return _failures
	.where((TestFailure failure) => failure.actual != 'Timeout');
	}

	String toString() {
	StringBuffer sb = new StringBuffer();
	sb.write('$buildUri\n');
	sb.write('Failures:\n${_failures.join('\n-----\n')}\n');
	sb.write('\nTimings:\n${_timings.join('\n')}');
	return sb.toString();
	}
	}

	/// The [Uri] of a build step stdio log split into its subparts.
	class BuildUri {
	final String scheme;
	final String host;
	final String prefix;
	final String botName;
	final int buildNumber;
	final String stepName;
	final String suffix;

	factory BuildUri(Uri uri) {
	String scheme = uri.scheme;
	String host = uri.host;
	List<String> parts =
	split(uri.path, ['/builders/', '/builds/', '/steps/', '/logs/']);
	String prefix = parts[0];
	String botName = parts[1];
	int buildNumber = int.parse(parts[2]);
	String stepName = parts[3];
	String suffix = parts[4];
	return new BuildUri.internal(
	scheme, host, prefix, botName, buildNumber, stepName, suffix);
	}

	BuildUri.internal(this.scheme, this.host, this.prefix, this.botName,
	this.buildNumber, this.stepName, this.suffix);

	String get buildName =>
	'/builders/$botName/builds/$buildNumber/steps/$stepName';

	String get path => '$prefix$buildName/logs/$suffix';

	/// Creates the [Uri] for this build step stdio log.
	Uri toUri() {
	return new Uri(scheme: scheme, host: host, path: path);
	}

	/// Returns the [BuildUri] the previous build of this build step.
	BuildUri prev() {
	return new BuildUri.internal(
	scheme, host, prefix, botName, buildNumber - 1, stepName, suffix);
	}

	String toString() {
	return buildName;
	}
	}

	/// Id for a test on a specific configuration, for instance
	/// `dart2js-chrome release_x64/co19/Language/Metadata/before_function_t07`.
	class TestConfiguration {
	final String configName;
	final String testName;

	TestConfiguration(this.configName, this.testName);

	String toString() {
	return '$configName $testName';
	}

	int get hashCode => configName.hashCode * 17 + testName.hashCode * 19;

	bool operator ==(other) {
	if (identical(this, other)) return true;
	if (other is! TestConfiguration) return false;
	return configName == other.configName && testName == other.testName;
	}
	}

	/// Test failure data derived from the test failure summary in the build step
	/// stdio log.
	class TestFailure {
	final BuildUri uri;
	final TestConfiguration id;
	final String expected;
	final String actual;
	final String text;

	factory TestFailure(BuildUri uri, List<String> lines) {
	List<String> parts = split(lines.first, ['FAILED: ', ' ', ' ']);
	String configName = parts[1];
	String archName = parts[2];
	String testName = parts[3];
	TestConfiguration id =
	new TestConfiguration(configName, '$archName/$testName');
	String expected = split(lines[1], ['Expected: '])[1];
	String actual = split(lines[2], ['Actual: '])[1];
	return new TestFailure.internal(
	uri, id, expected, actual, lines.skip(3).join('\n'));
	}

	TestFailure.internal(
	this.uri, this.id, this.expected, this.actual, this.text);

	String toString() {
	StringBuffer sb = new StringBuffer();
	sb.write('FAILED: $id\n');
	sb.write('Expected: $expected\n');
	sb.write('Actual: $actual\n');
	sb.write(text);
	return sb.toString();
	}
	}

	/// Id for a single test step, for instance the compilation and run steps of
	/// a test.
	class TestStep {
	final String stepName;
	final TestConfiguration id;

	TestStep(this.stepName, this.id);

	String toString() {
	return '$stepName - $id';
	}

	int get hashCode => stepName.hashCode * 13 + id.hashCode * 17;

	bool operator ==(other) {
	if (identical(this, other)) return true;
	if (other is! TestStep) return false;
	return stepName == other.stepName && id == other.id;
	}
	}

	/// The timing result for a single test step.
	class Timing {
	final BuildUri uri;
	final String time;
	final TestStep step;

	Timing(this.uri, this.time, this.step);

	String toString() {
	return '$time - $step';
	}
	}

	/// Create the [Timing]s for the [line] as found in the top-20 timings of a
	/// build step stdio log.
	List<Timing> parseTimings(BuildUri uri, String line) {
	List<String> parts = split(line, [' - ', ' - ', ' ']);
	String time = parts[0];
	String stepName = parts[1];
	String configName = parts[2];
	String testNames = parts[3];
	List<Timing> timings = <Timing>[];
	for (String testName in testNames.split(',')) {
	timings.add(new Timing(
	uri,
	time,
	new TestStep(
	stepName, new TestConfiguration(configName, testName.trim()))));
	}
	return timings;
	}

	/// Split [text] using [infixes] as infix markers.
	List<String> split(String text, List<String> infixes) {
	List<String> result = <String>[];
	int start = 0;
	for (String infix in infixes) {
	int index = text.indexOf(infix, start);
	if (index == -1)
	throw "'$infix' not found in '$text' from offset ${start}.";
	result.add(text.substring(start, index));
	start = index + infix.length;
	}
	result.add(text.substring(start));
	return result;
	}

	/// Pad [text] with spaces to the right to fit [length].
	String padRight(String text, int length) {
	if (text.length < length) return '${text}${' ' * (length - text.length)}';
	return text;
	}

	void log(String text) {
	print(text);
	}