Use report_lines flag in flutter coverage (#90142)

* Use the report lines flag

* Handle major version bumps in the version check

* Fix existing tests and add a new test

packages/flutter_tools/lib/src/test/coverage_collector.dart

@@ -223,6 +223,8 @@ Future<Map<String, dynamic>> _getAllCoverage(
   bool Function(String) libraryPredicate,
   bool forceSequential,
 ) async {
+  final vm_service.Version version = await service.getVersion();
+  final bool reportLines = (version.major == 3 && version.minor >= 51) || version.major > 3;
   final vm_service.VM vm = await service.getVM();
   final List<Map<String, dynamic>> coverage = <Map<String, dynamic>>[];
   for (final vm_service.IsolateRef isolateRef in vm.isolates) {
@@ -253,6 +255,7 @@ Future<Map<String, dynamic>> _getAllCoverage(
         <String>['Coverage'],
         scriptId: scriptId,
         forceCompile: true,
+        reportLines: reportLines ? true : null,
       )
       .then((vm_service.SourceReport report) {
         sourceReports[scriptId] = report;
@@ -260,17 +263,20 @@ Future<Map<String, dynamic>> _getAllCoverage(
       if (forceSequential) {
         await null;
       }
+      futures.add(getSourceReport);
+      if (reportLines) {
+        continue;
+      }
       final Future<void> getObject = service
         .getObject(isolateRef.id, scriptId)
         .then((vm_service.Obj response) {
           final vm_service.Script script = response as vm_service.Script;
           scripts[scriptId] = script;
         });
-      futures.add(getSourceReport);
       futures.add(getObject);
     }
     await Future.wait(futures);
-    _buildCoverageMap(scripts, sourceReports, coverage);
+    _buildCoverageMap(scripts, sourceReports, coverage, reportLines);
   }
   return <String, dynamic>{'type': 'CodeCoverage', 'coverage': coverage};
 }
@@ -280,9 +286,10 @@ void _buildCoverageMap(
   Map<String, vm_service.Script> scripts,
   Map<String, vm_service.SourceReport> sourceReports,
   List<Map<String, dynamic>> coverage,
+  bool reportLines,
 ) {
   final Map<String, Map<int, int>> hitMaps = <String, Map<int, int>>{};
-  for (final String scriptId in scripts.keys) {
+  for (final String scriptId in sourceReports.keys) {
     final vm_service.SourceReport sourceReport = sourceReports[scriptId];
     for (final vm_service.SourceReportRange range in sourceReport.ranges) {
       final vm_service.SourceReportCoverage coverage = range.coverage;
@@ -297,21 +304,24 @@ void _buildCoverageMap(
       final Map<int, int> hitMap = hitMaps[uri];
       final List<int> hits = coverage.hits;
       final List<int> misses = coverage.misses;
-      final List<dynamic> tokenPositions = scripts[scriptRef.id].tokenPosTable;
-      // The token positions can be null if the script has no lines that may be covered.
-      if (tokenPositions == null) {
+      final List<dynamic> tokenPositions = scripts[scriptRef.id]?.tokenPosTable;
+      // The token positions can be null if the script has no lines that may be
+      // covered. It will also be null if reportLines is true.
+      if (tokenPositions == null && !reportLines) {
         continue;
       }
       if (hits != null) {
         for (final int hit in hits) {
-          final int line = _lineAndColumn(hit, tokenPositions)[0];
+          final int line =
+              reportLines ? hit : _lineAndColumn(hit, tokenPositions)[0];
           final int current = hitMap[line] ?? 0;
           hitMap[line] = current + 1;
         }
       }
       if (misses != null) {
         for (final int miss in misses) {
-          final int line = _lineAndColumn(miss, tokenPositions)[0];
+          final int line =
+              reportLines ? miss : _lineAndColumn(miss, tokenPositions)[0];
           hitMap[line] ??= 0;
         }
       }

packages/flutter_tools/test/general.shard/coverage_collector_test.dart

@@ -14,6 +14,10 @@ void main() {
   testWithoutContext('Coverage collector Can handle coverage SentinelException', () async {
     final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(
       requests: <VmServiceExpectation>[
+        FakeVmServiceRequest(
+          method: 'getVersion',
+          jsonResponse: Version(major: 3, minor: 50).toJson(),
+        ),
         FakeVmServiceRequest(
           method: 'getVM',
           jsonResponse: (VM.parse(<String, Object>{})
@@ -51,6 +55,10 @@ void main() {
   testWithoutContext('Coverage collector processes coverage and script data', () async {
     final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(
       requests: <VmServiceExpectation>[
+        FakeVmServiceRequest(
+          method: 'getVersion',
+          jsonResponse: Version(major: 3, minor: 50).toJson(),
+        ),
         FakeVmServiceRequest(
           method: 'getVM',
           jsonResponse: (VM.parse(<String, Object>{})
@@ -138,4 +146,87 @@ void main() {
     ]});
     expect(fakeVmServiceHost.hasRemainingExpectations, false);
   });
+
+  testWithoutContext('Coverage collector skips loading Script objects when reportLines is available', () async {
+    final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(
+      requests: <VmServiceExpectation>[
+        FakeVmServiceRequest(
+          method: 'getVersion',
+          jsonResponse: Version(major: 3, minor: 51).toJson(),
+        ),
+        FakeVmServiceRequest(
+          method: 'getVM',
+          jsonResponse: (VM.parse(<String, Object>{})
+            ..isolates = <IsolateRef>[
+              IsolateRef.parse(<String, Object>{
+                'id': '1'
+              }),
+            ]
+          ).toJson(),
+        ),
+        FakeVmServiceRequest(
+          method: 'getScripts',
+          args: <String, Object>{
+            'isolateId': '1',
+          },
+          jsonResponse: ScriptList(scripts: <ScriptRef>[
+            ScriptRef(uri: 'foo.dart', id: '1'),
+          ]).toJson(),
+        ),
+        FakeVmServiceRequest(
+          method: 'getSourceReport',
+          args: <String, Object>{
+            'isolateId': '1',
+            'reports': <Object>['Coverage'],
+            'scriptId': '1',
+            'forceCompile': true,
+            'reportLines': true,
+          },
+          jsonResponse: SourceReport(
+            ranges: <SourceReportRange>[
+              SourceReportRange(
+                scriptIndex: 0,
+                startPos: 0,
+                endPos: 0,
+                compiled: true,
+                coverage: SourceReportCoverage(
+                  hits: <int>[1, 3],
+                  misses: <int>[2],
+                ),
+              ),
+            ],
+            scripts: <ScriptRef>[
+              ScriptRef(
+                uri: 'foo.dart',
+                id: '1',
+              ),
+            ],
+          ).toJson(),
+        ),
+      ],
+    );
+
+    final Map<String, Object> result = await collect(
+      null,
+      (String predicate) => true,
+      connector: (Uri uri) async {
+        return fakeVmServiceHost.vmService;
+      },
+    );
+
+    expect(result, <String, Object>{'type': 'CodeCoverage', 'coverage': <Object>[
+      <String, Object>{
+        'source': 'foo.dart',
+        'script': <String, Object>{
+          'type': '@Script',
+          'fixedId': true,
+          'id': 'libraries/1/scripts/foo.dart',
+          'uri': 'foo.dart',
+          '_kind': 'library',
+        },
+        'hits': <Object>[1, 1, 3, 1, 2, 0],
+      },
+    ]});
+    expect(fakeVmServiceHost.hasRemainingExpectations, false);
+  });
 }