lib/src/collect.dart - third_party/coverage - Git at Google

 // Copyright (c) 2014, 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.

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

 import 'package:vm_service/vm_service.dart';

 import 'hitmap.dart';
 import 'util.dart';

 const _retryInterval = Duration(milliseconds: 200);
 const _debugTokenPositions = bool.fromEnvironment('DEBUG_COVERAGE');

 /// Collects coverage for all isolates in the running VM.
 ///
 /// Collects a hit-map containing merged coverage for all isolates in the Dart
 /// VM associated with the specified [serviceUri]. Returns a map suitable for
 /// input to the coverage formatters that ship with this package.
 ///
 /// [serviceUri] must specify the http/https URI of the service port of a
 /// running Dart VM and must not be null.
 ///
 /// If [resume] is true, all isolates will be resumed once coverage collection
 /// is complete.
 ///
 /// If [waitPaused] is true, collection will not begin until all isolates are
 /// in the paused state.
 ///
 /// If [includeDart] is true, code coverage for core `dart:*` libraries will be
 /// collected.
 ///
 /// If [functionCoverage] is true, function coverage information will be
 /// collected.
 ///
 /// If [branchCoverage] is true, branch coverage information will be collected.
 /// This will only work correctly if the target VM was run with the
 /// --branch-coverage flag.
 ///
 /// If [scopedOutput] is non-empty, coverage will be restricted so that only
 /// scripts that start with any of the provided paths are considered.
 ///
 /// if [isolateIds] is set, the coverage gathering will be restricted to only
 /// those VM isolates.
 ///
 /// [serviceOverrideForTesting] is for internal testing only, and should not be
 /// set by users.
 Future<Map<String, dynamic>> collect(Uri serviceUri, bool resume,
     bool waitPaused, bool includeDart, Set<String>? scopedOutput,
     {Set<String>? isolateIds,
     Duration? timeout,
     bool functionCoverage = false,
     bool branchCoverage = false,
     VmService? serviceOverrideForTesting}) async {
   scopedOutput ??= <String>{};

   late VmService service;
   if (serviceOverrideForTesting != null) {
     service = serviceOverrideForTesting;
   } else {
     // Create websocket URI. Handle any trailing slashes.
     final pathSegments =
         serviceUri.pathSegments.where((c) => c.isNotEmpty).toList()..add('ws');
     final uri = serviceUri.replace(scheme: 'ws', pathSegments: pathSegments);

     await retry(() async {
       try {
         final options = const CompressionOptions(enabled: false);
         final socket = await WebSocket.connect('$uri', compression: options);
         final controller = StreamController<String>();
         socket.listen((data) => controller.add(data as String), onDone: () {
           controller.close();
           service.dispose();
         });
         service = VmService(
             controller.stream, (String message) => socket.add(message),
             log: StdoutLog(), disposeHandler: () => socket.close());
         await service.getVM().timeout(_retryInterval);
       } on TimeoutException {
         // The signature changed in vm_service version 6.0.0.
         // ignore: await_only_futures
         await service.dispose();
         rethrow;
       }
     }, _retryInterval, timeout: timeout);
   }

   try {
     if (waitPaused) {
       await _waitIsolatesPaused(service, timeout: timeout);
     }

     return await _getAllCoverage(service, includeDart, functionCoverage,
         branchCoverage, scopedOutput, isolateIds);
   } finally {
     if (resume) {
       await _resumeIsolates(service);
     }
     // The signature changed in vm_service version 6.0.0.
     // ignore: await_only_futures
     await service.dispose();
   }
 }

 bool _versionCheck(Version version, int minMajor, int minMinor) {
   final major = version.major ?? 0;
   final minor = version.minor ?? 0;
   return major > minMajor || (major == minMajor && minor >= minMinor);
 }

 Future<Map<String, dynamic>> _getAllCoverage(
     VmService service,
     bool includeDart,
     bool functionCoverage,
     bool branchCoverage,
     Set<String>? scopedOutput,
     Set<String>? isolateIds) async {
   scopedOutput ??= <String>{};
   final vm = await service.getVM();
   final allCoverage = <Map<String, dynamic>>[];
   final version = await service.getVersion();
   final reportLines = _versionCheck(version, 3, 51);
   final branchCoverageSupported = _versionCheck(version, 3, 56);
   final libraryFilters = _versionCheck(version, 3, 57);
   final fastIsoGroups = _versionCheck(version, 3, 61);
   if (branchCoverage && !branchCoverageSupported) {
     branchCoverage = false;
     stderr.writeln('Branch coverage was requested, but is not supported'
         ' by the VM version. Try updating to a newer version of Dart');
   }
   final sourceReportKinds = [
     SourceReportKind.kCoverage,
     if (branchCoverage) SourceReportKind.kBranchCoverage,
   ];

   // Program counters are shared between isolates in the same group. So we need
   // to make sure we're only gathering coverage data for one isolate in each
   // group, otherwise we'll double count the hits.
   final isolateOwnerGroup = <String, String>{};
   final coveredIsolateGroups = <String>{};
   if (!fastIsoGroups) {
     for (var isolateGroupRef in vm.isolateGroups!) {
       final isolateGroup = await service.getIsolateGroup(isolateGroupRef.id!);
       for (var isolateRef in isolateGroup.isolates!) {
         isolateOwnerGroup[isolateRef.id!] = isolateGroupRef.id!;
       }
     }
   }

   for (var isolateRef in vm.isolates!) {
     if (isolateIds != null && !isolateIds.contains(isolateRef.id)) continue;
     final isolateGroupId = fastIsoGroups
         ? isolateRef.isolateGroupId
         : isolateOwnerGroup[isolateRef.id];
     if (isolateGroupId != null) {
       if (coveredIsolateGroups.contains(isolateGroupId)) continue;
       coveredIsolateGroups.add(isolateGroupId);
     }
     if (scopedOutput.isNotEmpty && !libraryFilters) {
       late final ScriptList scripts;
       try {
         scripts = await service.getScripts(isolateRef.id!);
       } on SentinelException {
         continue;
       }
       for (final script in scripts.scripts!) {
         final uri = Uri.parse(script.uri!);
         if (uri.scheme != 'package') continue;
         final scope = uri.path.split('/').first;
         // Skip scripts which should not be included in the report.
         if (!scopedOutput.contains(scope)) continue;
         late final SourceReport scriptReport;
         try {
           scriptReport = await service.getSourceReport(
               isolateRef.id!, sourceReportKinds,
               forceCompile: true,
               scriptId: script.id,
               reportLines: reportLines ? true : null);
         } on SentinelException {
           continue;
         }
         final coverage = await _getCoverageJson(service, isolateRef,
             scriptReport, includeDart, functionCoverage, reportLines);
         allCoverage.addAll(coverage);
       }
     } else {
       late final SourceReport isolateReport;
       try {
         isolateReport = await service.getSourceReport(
           isolateRef.id!,
           sourceReportKinds,
           forceCompile: true,
           reportLines: reportLines ? true : null,
           libraryFilters: scopedOutput.isNotEmpty && libraryFilters
               ? List.from(scopedOutput.map((filter) => 'package:$filter/'))
               : null,
         );
       } on SentinelException {
         continue;
       }
       final coverage = await _getCoverageJson(service, isolateRef,
           isolateReport, includeDart, functionCoverage, reportLines);
       allCoverage.addAll(coverage);
     }
   }
   return <String, dynamic>{'type': 'CodeCoverage', 'coverage': allCoverage};
 }

 Future _resumeIsolates(VmService service) async {
   final vm = await service.getVM();
   final futures = <Future>[];
   for (var isolateRef in vm.isolates!) {
     // Guard against sync as well as async errors: sync - when we are writing
     // message to the socket, the socket might be closed; async - when we are
     // waiting for the response, the socket again closes.
     futures.add(Future.sync(() async {
       final isolate = await service.getIsolate(isolateRef.id!);
       if (isolate.pauseEvent!.kind != EventKind.kResume) {
         await service.resume(isolateRef.id!);
       }
     }));
   }
   try {
     await Future.wait(futures);
   } catch (_) {
     // Ignore resume isolate failures
   }
 }

 Future _waitIsolatesPaused(VmService service, {Duration? timeout}) async {
   final pauseEvents = <String>{
     EventKind.kPauseStart,
     EventKind.kPauseException,
     EventKind.kPauseExit,
     EventKind.kPauseInterrupted,
     EventKind.kPauseBreakpoint
   };

   Future allPaused() async {
     final vm = await service.getVM();
     if (vm.isolates!.isEmpty) throw 'No isolates.';
     for (var isolateRef in vm.isolates!) {
       final isolate = await service.getIsolate(isolateRef.id!);
       if (!pauseEvents.contains(isolate.pauseEvent!.kind)) {
         throw 'Unpaused isolates remaining.';
       }
     }
   }

   return retry(allPaused, _retryInterval, timeout: timeout);
 }

 /// Returns the line number to which the specified token position maps.
 ///
 /// Performs a binary search within the script's token position table to locate
 /// the line in question.
 int? _getLineFromTokenPos(Script script, int tokenPos) {
   // TODO(cbracken): investigate whether caching this lookup results in
   // significant performance gains.
   var min = 0;
   var max = script.tokenPosTable!.length;
   while (min < max) {
     final mid = min + ((max - min) >> 1);
     final row = script.tokenPosTable![mid];
     if (row[1] > tokenPos) {
       max = mid;
     } else {
       for (var i = 1; i < row.length; i += 2) {
         if (row[i] == tokenPos) return row.first;
       }
       min = mid + 1;
     }
   }
   return null;
 }

 /// Returns a JSON coverage list backward-compatible with pre-1.16.0 SDKs.
 Future<List<Map<String, dynamic>>> _getCoverageJson(
     VmService service,
     IsolateRef isolateRef,
     SourceReport report,
     bool includeDart,
     bool functionCoverage,
     bool reportLines) async {
   final hitMaps = <Uri, HitMap>{};
   final scripts = <ScriptRef, Script>{};
   final libraries = <LibraryRef>{};
   final needScripts = functionCoverage || !reportLines;

   Future<Script?> getScript(ScriptRef? scriptRef) async {
     if (scriptRef == null) {
       return null;
     }
     if (!scripts.containsKey(scriptRef)) {
       scripts[scriptRef] =
           await service.getObject(isolateRef.id!, scriptRef.id!) as Script;
     }
     return scripts[scriptRef];
   }

   HitMap getHitMap(Uri scriptUri) =>
       hitMaps.putIfAbsent(scriptUri, () => HitMap());

   Future<void> processFunction(FuncRef funcRef) async {
     final func = await service.getObject(isolateRef.id!, funcRef.id!) as Func;
     if ((func.implicit ?? false) || (func.isAbstract ?? false)) {
       return;
     }
     final location = func.location;
     if (location == null) {
       return;
     }
     final script = await getScript(location.script);
     if (script == null) {
       return;
     }
     final funcName = await _getFuncName(service, isolateRef, func);
     final tokenPos = location.tokenPos!;
     final line = _getLineFromTokenPos(script, tokenPos);
     if (line == null) {
       if (_debugTokenPositions) {
         stderr.writeln(
             'tokenPos $tokenPos in function ${funcRef.name} has no line '
             'mapping for script ${script.uri!}');
       }
       return;
     }
     final hits = getHitMap(Uri.parse(script.uri!));
     hits.funcHits ??= <int, int>{};
     (hits.funcNames ??= <int, String>{})[line] = funcName;
   }

   for (var range in report.ranges!) {
     final scriptRef = report.scripts![range.scriptIndex!];
     final scriptUri = Uri.parse(scriptRef.uri!);

     // Not returned in scripts section of source report.
     if (scriptUri.scheme == 'evaluate') continue;

     // Skip scripts from dart:.
     if (!includeDart && scriptUri.scheme == 'dart') continue;

     // Look up the hit maps for this script (shared across isolates).
     final hits = getHitMap(scriptUri);

     Script? script;
     if (needScripts) {
       script = await getScript(scriptRef);
       if (script == null) continue;
     }

     // If the script's library isn't loaded, load it then look up all its funcs.
     final libRef = script?.library;
     if (functionCoverage && libRef != null && !libraries.contains(libRef)) {
       libraries.add(libRef);
       final library =
           await service.getObject(isolateRef.id!, libRef.id!) as Library;
       if (library.functions != null) {
         for (var funcRef in library.functions!) {
           await processFunction(funcRef);
         }
       }
       if (library.classes != null) {
         for (var classRef in library.classes!) {
           final clazz =
               await service.getObject(isolateRef.id!, classRef.id!) as Class;
           if (clazz.functions != null) {
             for (var funcRef in clazz.functions!) {
               await processFunction(funcRef);
             }
           }
         }
       }
     }

     // Collect hits and misses.
     final coverage = range.coverage;

     if (coverage == null) continue;

     void forEachLine(List<int> tokenPositions, void Function(int line) body) {
       for (final pos in tokenPositions) {
         final line = reportLines ? pos : _getLineFromTokenPos(script!, pos);
         if (line == null) {
           if (_debugTokenPositions) {
             stderr.write(
                 'tokenPos $pos has no line mapping for script $scriptUri');
           }
           continue;
         }
         body(line);
       }
     }

     forEachLine(coverage.hits!, (line) {
       hits.lineHits.increment(line);
       if (hits.funcNames != null && hits.funcNames!.containsKey(line)) {
         hits.funcHits!.increment(line);
       }
     });
     forEachLine(coverage.misses!, (line) {
       hits.lineHits.putIfAbsent(line, () => 0);
     });
     hits.funcNames?.forEach((line, funcName) {
       hits.funcHits?.putIfAbsent(line, () => 0);
     });

     final branchCoverage = range.branchCoverage;
     if (branchCoverage != null) {
       hits.branchHits ??= <int, int>{};
       forEachLine(branchCoverage.hits!, (line) {
         hits.branchHits!.increment(line);
       });
       forEachLine(branchCoverage.misses!, (line) {
         hits.branchHits!.putIfAbsent(line, () => 0);
       });
     }
   }

   // Output JSON
   final coverage = <Map<String, dynamic>>[];
   hitMaps.forEach((uri, hits) {
     coverage.add(hitmapToJson(hits, uri));
   });
   return coverage;
 }

 extension _MapExtension<T> on Map<T, int> {
   void increment(T key) => this[key] = (this[key] ?? 0) + 1;
 }

 Future<String> _getFuncName(
     VmService service, IsolateRef isolateRef, Func func) async {
   if (func.name == null) {
     return '${func.type}:${func.location!.tokenPos}';
   }
   final owner = func.owner;
   if (owner is ClassRef) {
     final cls = await service.getObject(isolateRef.id!, owner.id!) as Class;
     if (cls.name != null) return '${cls.name}.${func.name}';
   }
   return func.name!;
 }

 class StdoutLog extends Log {
   @override
   void warning(String message) => print(message);

   @override
   void severe(String message) => print(message);
 }
	// Copyright (c) 2014, 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.

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

	import 'package:vm_service/vm_service.dart';

	import 'hitmap.dart';
	import 'util.dart';

	const _retryInterval = Duration(milliseconds: 200);
	const _debugTokenPositions = bool.fromEnvironment('DEBUG_COVERAGE');

	/// Collects coverage for all isolates in the running VM.
	///
	/// Collects a hit-map containing merged coverage for all isolates in the Dart
	/// VM associated with the specified [serviceUri]. Returns a map suitable for
	/// input to the coverage formatters that ship with this package.
	///
	/// [serviceUri] must specify the http/https URI of the service port of a
	/// running Dart VM and must not be null.
	///
	/// If [resume] is true, all isolates will be resumed once coverage collection
	/// is complete.
	///
	/// If [waitPaused] is true, collection will not begin until all isolates are
	/// in the paused state.
	///
	/// If [includeDart] is true, code coverage for core `dart:*` libraries will be
	/// collected.
	///
	/// If [functionCoverage] is true, function coverage information will be
	/// collected.
	///
	/// If [branchCoverage] is true, branch coverage information will be collected.
	/// This will only work correctly if the target VM was run with the
	/// --branch-coverage flag.
	///
	/// If [scopedOutput] is non-empty, coverage will be restricted so that only
	/// scripts that start with any of the provided paths are considered.
	///
	/// if [isolateIds] is set, the coverage gathering will be restricted to only
	/// those VM isolates.
	///
	/// [serviceOverrideForTesting] is for internal testing only, and should not be
	/// set by users.
	Future<Map<String, dynamic>> collect(Uri serviceUri, bool resume,
	bool waitPaused, bool includeDart, Set<String>? scopedOutput,
	{Set<String>? isolateIds,
	Duration? timeout,
	bool functionCoverage = false,
	bool branchCoverage = false,
	VmService? serviceOverrideForTesting}) async {
	scopedOutput ??= <String>{};

	late VmService service;
	if (serviceOverrideForTesting != null) {
	service = serviceOverrideForTesting;
	} else {
	// Create websocket URI. Handle any trailing slashes.
	final pathSegments =
	serviceUri.pathSegments.where((c) => c.isNotEmpty).toList()..add('ws');
	final uri = serviceUri.replace(scheme: 'ws', pathSegments: pathSegments);

	await retry(() async {
	try {
	final options = const CompressionOptions(enabled: false);
	final socket = await WebSocket.connect('$uri', compression: options);
	final controller = StreamController<String>();
	socket.listen((data) => controller.add(data as String), onDone: () {
	controller.close();
	service.dispose();
	});
	service = VmService(
	controller.stream, (String message) => socket.add(message),
	log: StdoutLog(), disposeHandler: () => socket.close());
	await service.getVM().timeout(_retryInterval);
	} on TimeoutException {
	// The signature changed in vm_service version 6.0.0.
	// ignore: await_only_futures
	await service.dispose();
	rethrow;
	}
	}, _retryInterval, timeout: timeout);
	}

	try {
	if (waitPaused) {
	await _waitIsolatesPaused(service, timeout: timeout);
	}

	return await _getAllCoverage(service, includeDart, functionCoverage,
	branchCoverage, scopedOutput, isolateIds);
	} finally {
	if (resume) {
	await _resumeIsolates(service);
	}
	// The signature changed in vm_service version 6.0.0.
	// ignore: await_only_futures
	await service.dispose();
	}
	}

	bool _versionCheck(Version version, int minMajor, int minMinor) {
	final major = version.major ?? 0;
	final minor = version.minor ?? 0;
	return major > minMajor \|\| (major == minMajor && minor >= minMinor);
	}

	Future<Map<String, dynamic>> _getAllCoverage(
	VmService service,
	bool includeDart,
	bool functionCoverage,
	bool branchCoverage,
	Set<String>? scopedOutput,
	Set<String>? isolateIds) async {
	scopedOutput ??= <String>{};
	final vm = await service.getVM();
	final allCoverage = <Map<String, dynamic>>[];
	final version = await service.getVersion();
	final reportLines = _versionCheck(version, 3, 51);
	final branchCoverageSupported = _versionCheck(version, 3, 56);
	final libraryFilters = _versionCheck(version, 3, 57);
	final fastIsoGroups = _versionCheck(version, 3, 61);
	if (branchCoverage && !branchCoverageSupported) {
	branchCoverage = false;
	stderr.writeln('Branch coverage was requested, but is not supported'
	' by the VM version. Try updating to a newer version of Dart');
	}
	final sourceReportKinds = [
	SourceReportKind.kCoverage,
	if (branchCoverage) SourceReportKind.kBranchCoverage,
	];

	// Program counters are shared between isolates in the same group. So we need
	// to make sure we're only gathering coverage data for one isolate in each
	// group, otherwise we'll double count the hits.
	final isolateOwnerGroup = <String, String>{};
	final coveredIsolateGroups = <String>{};
	if (!fastIsoGroups) {
	for (var isolateGroupRef in vm.isolateGroups!) {
	final isolateGroup = await service.getIsolateGroup(isolateGroupRef.id!);
	for (var isolateRef in isolateGroup.isolates!) {
	isolateOwnerGroup[isolateRef.id!] = isolateGroupRef.id!;
	}
	}
	}

	for (var isolateRef in vm.isolates!) {
	if (isolateIds != null && !isolateIds.contains(isolateRef.id)) continue;
	final isolateGroupId = fastIsoGroups
	? isolateRef.isolateGroupId
	: isolateOwnerGroup[isolateRef.id];
	if (isolateGroupId != null) {
	if (coveredIsolateGroups.contains(isolateGroupId)) continue;
	coveredIsolateGroups.add(isolateGroupId);
	}
	if (scopedOutput.isNotEmpty && !libraryFilters) {
	late final ScriptList scripts;
	try {
	scripts = await service.getScripts(isolateRef.id!);
	} on SentinelException {
	continue;
	}
	for (final script in scripts.scripts!) {
	final uri = Uri.parse(script.uri!);
	if (uri.scheme != 'package') continue;
	final scope = uri.path.split('/').first;
	// Skip scripts which should not be included in the report.
	if (!scopedOutput.contains(scope)) continue;
	late final SourceReport scriptReport;
	try {
	scriptReport = await service.getSourceReport(
	isolateRef.id!, sourceReportKinds,
	forceCompile: true,
	scriptId: script.id,
	reportLines: reportLines ? true : null);
	} on SentinelException {
	continue;
	}
	final coverage = await _getCoverageJson(service, isolateRef,
	scriptReport, includeDart, functionCoverage, reportLines);
	allCoverage.addAll(coverage);
	}
	} else {
	late final SourceReport isolateReport;
	try {
	isolateReport = await service.getSourceReport(
	isolateRef.id!,
	sourceReportKinds,
	forceCompile: true,
	reportLines: reportLines ? true : null,
	libraryFilters: scopedOutput.isNotEmpty && libraryFilters
	? List.from(scopedOutput.map((filter) => 'package:$filter/'))
	: null,
	);
	} on SentinelException {
	continue;
	}
	final coverage = await _getCoverageJson(service, isolateRef,
	isolateReport, includeDart, functionCoverage, reportLines);
	allCoverage.addAll(coverage);
	}
	}
	return <String, dynamic>{'type': 'CodeCoverage', 'coverage': allCoverage};
	}

	Future _resumeIsolates(VmService service) async {
	final vm = await service.getVM();
	final futures = <Future>[];
	for (var isolateRef in vm.isolates!) {
	// Guard against sync as well as async errors: sync - when we are writing
	// message to the socket, the socket might be closed; async - when we are
	// waiting for the response, the socket again closes.
	futures.add(Future.sync(() async {
	final isolate = await service.getIsolate(isolateRef.id!);
	if (isolate.pauseEvent!.kind != EventKind.kResume) {
	await service.resume(isolateRef.id!);
	}
	}));
	}
	try {
	await Future.wait(futures);
	} catch (_) {
	// Ignore resume isolate failures
	}
	}

	Future _waitIsolatesPaused(VmService service, {Duration? timeout}) async {
	final pauseEvents = <String>{
	EventKind.kPauseStart,
	EventKind.kPauseException,
	EventKind.kPauseExit,
	EventKind.kPauseInterrupted,
	EventKind.kPauseBreakpoint
	};

	Future allPaused() async {
	final vm = await service.getVM();
	if (vm.isolates!.isEmpty) throw 'No isolates.';
	for (var isolateRef in vm.isolates!) {
	final isolate = await service.getIsolate(isolateRef.id!);
	if (!pauseEvents.contains(isolate.pauseEvent!.kind)) {
	throw 'Unpaused isolates remaining.';
	}
	}
	}

	return retry(allPaused, _retryInterval, timeout: timeout);
	}

	/// Returns the line number to which the specified token position maps.
	///
	/// Performs a binary search within the script's token position table to locate
	/// the line in question.
	int? _getLineFromTokenPos(Script script, int tokenPos) {
	// TODO(cbracken): investigate whether caching this lookup results in
	// significant performance gains.
	var min = 0;
	var max = script.tokenPosTable!.length;
	while (min < max) {
	final mid = min + ((max - min) >> 1);
	final row = script.tokenPosTable![mid];
	if (row[1] > tokenPos) {
	max = mid;
	} else {
	for (var i = 1; i < row.length; i += 2) {
	if (row[i] == tokenPos) return row.first;
	}
	min = mid + 1;
	}
	}
	return null;
	}

	/// Returns a JSON coverage list backward-compatible with pre-1.16.0 SDKs.
	Future<List<Map<String, dynamic>>> _getCoverageJson(
	VmService service,
	IsolateRef isolateRef,
	SourceReport report,
	bool includeDart,
	bool functionCoverage,
	bool reportLines) async {
	final hitMaps = <Uri, HitMap>{};
	final scripts = <ScriptRef, Script>{};
	final libraries = <LibraryRef>{};
	final needScripts = functionCoverage \|\| !reportLines;

	Future<Script?> getScript(ScriptRef? scriptRef) async {
	if (scriptRef == null) {
	return null;
	}
	if (!scripts.containsKey(scriptRef)) {
	scripts[scriptRef] =
	await service.getObject(isolateRef.id!, scriptRef.id!) as Script;
	}
	return scripts[scriptRef];
	}

	HitMap getHitMap(Uri scriptUri) =>
	hitMaps.putIfAbsent(scriptUri, () => HitMap());

	Future<void> processFunction(FuncRef funcRef) async {
	final func = await service.getObject(isolateRef.id!, funcRef.id!) as Func;
	if ((func.implicit ?? false) \|\| (func.isAbstract ?? false)) {
	return;
	}
	final location = func.location;
	if (location == null) {
	return;
	}
	final script = await getScript(location.script);
	if (script == null) {
	return;
	}
	final funcName = await _getFuncName(service, isolateRef, func);
	final tokenPos = location.tokenPos!;
	final line = _getLineFromTokenPos(script, tokenPos);
	if (line == null) {
	if (_debugTokenPositions) {
	stderr.writeln(
	'tokenPos $tokenPos in function ${funcRef.name} has no line '
	'mapping for script ${script.uri!}');
	}
	return;
	}
	final hits = getHitMap(Uri.parse(script.uri!));
	hits.funcHits ??= <int, int>{};
	(hits.funcNames ??= <int, String>{})[line] = funcName;
	}

	for (var range in report.ranges!) {
	final scriptRef = report.scripts![range.scriptIndex!];
	final scriptUri = Uri.parse(scriptRef.uri!);

	// Not returned in scripts section of source report.
	if (scriptUri.scheme == 'evaluate') continue;

	// Skip scripts from dart:.
	if (!includeDart && scriptUri.scheme == 'dart') continue;

	// Look up the hit maps for this script (shared across isolates).
	final hits = getHitMap(scriptUri);

	Script? script;
	if (needScripts) {
	script = await getScript(scriptRef);
	if (script == null) continue;
	}

	// If the script's library isn't loaded, load it then look up all its funcs.
	final libRef = script?.library;
	if (functionCoverage && libRef != null && !libraries.contains(libRef)) {
	libraries.add(libRef);
	final library =
	await service.getObject(isolateRef.id!, libRef.id!) as Library;
	if (library.functions != null) {
	for (var funcRef in library.functions!) {
	await processFunction(funcRef);
	}
	}
	if (library.classes != null) {
	for (var classRef in library.classes!) {
	final clazz =
	await service.getObject(isolateRef.id!, classRef.id!) as Class;
	if (clazz.functions != null) {
	for (var funcRef in clazz.functions!) {
	await processFunction(funcRef);
	}
	}
	}
	}
	}

	// Collect hits and misses.
	final coverage = range.coverage;

	if (coverage == null) continue;

	void forEachLine(List<int> tokenPositions, void Function(int line) body) {
	for (final pos in tokenPositions) {
	final line = reportLines ? pos : _getLineFromTokenPos(script!, pos);
	if (line == null) {
	if (_debugTokenPositions) {
	stderr.write(
	'tokenPos $pos has no line mapping for script $scriptUri');
	}
	continue;
	}
	body(line);
	}
	}

	forEachLine(coverage.hits!, (line) {
	hits.lineHits.increment(line);
	if (hits.funcNames != null && hits.funcNames!.containsKey(line)) {
	hits.funcHits!.increment(line);
	}
	});
	forEachLine(coverage.misses!, (line) {
	hits.lineHits.putIfAbsent(line, () => 0);
	});
	hits.funcNames?.forEach((line, funcName) {
	hits.funcHits?.putIfAbsent(line, () => 0);
	});

	final branchCoverage = range.branchCoverage;
	if (branchCoverage != null) {
	hits.branchHits ??= <int, int>{};
	forEachLine(branchCoverage.hits!, (line) {
	hits.branchHits!.increment(line);
	});
	forEachLine(branchCoverage.misses!, (line) {
	hits.branchHits!.putIfAbsent(line, () => 0);
	});
	}
	}

	// Output JSON
	final coverage = <Map<String, dynamic>>[];
	hitMaps.forEach((uri, hits) {
	coverage.add(hitmapToJson(hits, uri));
	});
	return coverage;
	}

	extension _MapExtension<T> on Map<T, int> {
	void increment(T key) => this[key] = (this[key] ?? 0) + 1;
	}

	Future<String> _getFuncName(
	VmService service, IsolateRef isolateRef, Func func) async {
	if (func.name == null) {
	return '${func.type}:${func.location!.tokenPos}';
	}
	final owner = func.owner;
	if (owner is ClassRef) {
	final cls = await service.getObject(isolateRef.id!, owner.id!) as Class;
	if (cls.name != null) return '${cls.name}.${func.name}';
	}
	return func.name!;
	}

	class StdoutLog extends Log {
	@override
	void warning(String message) => print(message);

	@override
	void severe(String message) => print(message);
	}