diff --git a/pkgs/coverage/analysis_options.yaml b/pkgs/coverage/analysis_options.yaml
index bb1afe05ab..62aab638e0 100644
--- a/pkgs/coverage/analysis_options.yaml
+++ b/pkgs/coverage/analysis_options.yaml
@@ -1,6 +1,8 @@
 include: package:dart_flutter_team_lints/analysis_options.yaml
 
 analyzer:
+  errors:
+    unnecessary_this: ignore
   language:
     strict-casts: true
 
diff --git a/pkgs/coverage/lib/src/collect.dart b/pkgs/coverage/lib/src/collect.dart
index 76227bac9f..62e56146c6 100644
--- a/pkgs/coverage/lib/src/collect.dart
+++ b/pkgs/coverage/lib/src/collect.dart
@@ -42,8 +42,9 @@ const _debugTokenPositions = bool.fromEnvironment('DEBUG_COVERAGE');
 /// 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.
+/// If [isolateIds] is set, coverage gathering **will not be restricted** to
+/// only those VM isolates. Instead, coverage will be collected for **all isolates
+/// in the same isolate group** as the provided isolate(s). 
 ///
 /// If [coverableLineCache] is set, the collector will avoid recompiling
 /// libraries it has already seen (see VmService.getSourceReport's
diff --git a/pkgs/coverage/lib/src/formatter.dart b/pkgs/coverage/lib/src/formatter.dart
index a37df73b7f..1d305c4bea 100644
--- a/pkgs/coverage/lib/src/formatter.dart
+++ b/pkgs/coverage/lib/src/formatter.dart
@@ -2,6 +2,8 @@
 // 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.
 
+// ignore_for_file: unnecessary_this
+
 import 'package:glob/glob.dart';
 import 'package:path/path.dart' as p;
 
@@ -78,12 +80,19 @@ extension FileHitMapsFormatter on Map<String, HitMap> {
     String? basePath,
     List<String>? reportOn,
     Set<Glob>? ignoreGlobs,
+    bool Function(String path)? includeUncovered,
   }) {
     final pathFilter = _getPathFilter(
       reportOn: reportOn,
       ignoreGlobs: ignoreGlobs,
     );
     final buf = StringBuffer();
+
+    // Get all Dart files in the project
+    final allDartFiles = resolver.listAllDartFiles().toSet();
+    final coveredFiles = this.keys.toSet();
+    final uncoveredFiles = allDartFiles.difference(coveredFiles);
+
     for (final entry in entries) {
       final v = entry.value;
       final lineHits = v.lineHits;
@@ -91,13 +100,7 @@ extension FileHitMapsFormatter on Map<String, HitMap> {
       final funcNames = v.funcNames;
       final branchHits = v.branchHits;
       var source = resolver.resolve(entry.key);
-      if (source == null) {
-        continue;
-      }
-
-      if (!pathFilter(source)) {
-        continue;
-      }
+      if (source == null || !pathFilter(source)) continue;
 
       if (basePath != null) {
         source = p.relative(source, from: basePath);
@@ -129,6 +132,21 @@ extension FileHitMapsFormatter on Map<String, HitMap> {
       buf.write('end_of_record\n');
     }
 
+    // Add uncovered files if allowed
+    for (final file in uncoveredFiles) {
+      if (includeUncovered != null && !includeUncovered(file)) continue;
+      var source = resolver.resolve(file);
+      if (source == null || !pathFilter(source)) continue;
+      if (basePath != null) {
+        source = p.relative(source, from: basePath);
+      }
+
+      buf.write('SF:$source\n');
+      buf.write('LF:0\n');
+      buf.write('LH:0\n');
+      buf.write('end_of_record\n');
+    }
+
     return buf.toString();
   }
 
@@ -144,12 +162,19 @@ extension FileHitMapsFormatter on Map<String, HitMap> {
     Set<Glob>? ignoreGlobs,
     bool reportFuncs = false,
     bool reportBranches = false,
+    bool Function(String path)? includeUncovered,
   }) async {
     final pathFilter = _getPathFilter(
       reportOn: reportOn,
       ignoreGlobs: ignoreGlobs,
     );
     final buf = StringBuffer();
+
+    // Get all Dart files in the project
+    final allDartFiles = resolver.listAllDartFiles().toSet();
+    final coveredFiles = this.keys.toSet();
+    final uncoveredFiles = allDartFiles.difference(coveredFiles);
+
     for (final entry in entries) {
       final v = entry.value;
       if (reportFuncs && v.funcHits == null) {
@@ -171,18 +196,10 @@ extension FileHitMapsFormatter on Map<String, HitMap> {
               ? v.branchHits!
               : v.lineHits;
       final source = resolver.resolve(entry.key);
-      if (source == null) {
-        continue;
-      }
-
-      if (!pathFilter(source)) {
-        continue;
-      }
+      if (source == null || !pathFilter(source)) continue;
 
       final lines = await loader.load(source);
-      if (lines == null) {
-        continue;
-      }
+      if (lines == null) continue;
       buf.writeln(source);
       for (var line = 1; line <= lines.length; line++) {
         var prefix = _prefix;
@@ -193,6 +210,20 @@ extension FileHitMapsFormatter on Map<String, HitMap> {
       }
     }
 
+    // Add uncovered files if allowed
+    for (final file in uncoveredFiles) {
+      if (includeUncovered != null && !includeUncovered(file)) continue;
+      final source = resolver.resolve(file);
+      if (source == null || !pathFilter(source)) continue;
+
+      final lines = await loader.load(source);
+      if (lines == null) continue;
+      buf.writeln(source);
+      for (final line in lines) {
+        buf.writeln('       |$line');
+      }
+    }
+
     return buf.toString();
   }
 }
@@ -221,3 +252,4 @@ _PathFilter _getPathFilter({List<String>? reportOn, Set<Glob>? ignoreGlobs}) {
     return true;
   };
 }
+
diff --git a/pkgs/coverage/lib/src/resolver.dart b/pkgs/coverage/lib/src/resolver.dart
index cb5b728894..263d2c17dc 100644
--- a/pkgs/coverage/lib/src/resolver.dart
+++ b/pkgs/coverage/lib/src/resolver.dart
@@ -9,6 +9,19 @@ import 'package:path/path.dart' as p;
 
 /// [Resolver] resolves imports with respect to a given environment.
 class Resolver {
+  /// Returns a list of all Dart files in the project.
+  List<String> listAllDartFiles({String directoryPath = '.'}) {
+    final dir = Directory(directoryPath);
+    if (!dir.existsSync()) return [];
+
+    return dir
+        .listSync(recursive: true)
+        .whereType<File>()
+        .where((file) => file.path.endsWith('.dart'))
+        .map((file) => file.path)
+        .toList();
+  }
+
   @Deprecated('Use Resolver.create')
   Resolver({this.packagesPath, this.sdkRoot})
       : _packages = packagesPath != null ? _parsePackages(packagesPath) : null,
diff --git a/pkgs/coverage/test/run_and_collect_test.dart b/pkgs/coverage/test/run_and_collect_test.dart
index e371f90005..6714b81744 100644
--- a/pkgs/coverage/test/run_and_collect_test.dart
+++ b/pkgs/coverage/test/run_and_collect_test.dart
@@ -69,6 +69,10 @@ class ThrowingResolver implements Resolver {
 
   @override
   String? get sdkRoot => throw UnimplementedError();
+
+  @override
+  List<String> listAllDartFiles({String directoryPath = '.'}) =>
+      throw UnimplementedError();
 }
 
 void checkIgnoredLinesInFilesCache(