Default failure summary for expanded reporter

Author: Telomelonia

pkgs/test/test/runner/compact_reporter_test.dart

@@ -562,6 +562,7 @@ void main() {
       );
     });
   }, testOn: 'windows');
+
 }
 
 Future<void> _expectReport(

pkgs/test/test/runner/expanded_reporter_test.dart

@@ -61,7 +61,12 @@ void main() {
           oh no
           test.dart 8:33  main.<fn>
 
-        +0 -3: Some tests failed.''',
+        +0 -3: Some tests failed.
+
+        Failing tests:
+          test.dart: failure 1
+          test.dart: failure 2
+          test.dart: failure 3''',
     );
   });
 
@@ -102,7 +107,11 @@ void main() {
           test.dart 8:33  main.<fn>
 
         +1 -2: success 2
-        +2 -2: Some tests failed.''',
+        +2 -2: Some tests failed.
+
+        Failing tests:
+          test.dart: failure 1
+          test.dart: failure 2''',
     );
   });
 
@@ -156,7 +165,10 @@ void main() {
           test.dart 12:18  main.<fn>
 
         +0 -1: wait
-        +1 -1: Some tests failed.''',
+        +1 -1: Some tests failed.
+
+        Failing tests:
+          test.dart: failures''',
     );
   });
 
@@ -260,7 +272,10 @@ void main() {
         five
         six
         +0 -1: wait
-        +1 -1: Some tests failed.''',
+        +1 -1: Some tests failed.
+
+        Failing tests:
+          test.dart: test''',
       );
     });
   });
@@ -340,7 +355,11 @@ void main() {
 
           +1 ~1 -2: skip 2
           +1 ~2 -2: success 2
-          +2 ~2 -2: Some tests failed.''',
+          +2 ~2 -2: Some tests failed.
+
+          Failing tests:
+            test.dart: failure 1
+            test.dart: failure 2''',
       );
     });
 
@@ -386,6 +405,9 @@ void main() {
 
         +0 -1: Some tests failed.
 
+        Failing tests:
+          test.dart: failure 1
+
         Consider enabling the flag chain-stack-traces to receive more detailed exceptions.
         For example, 'dart test --chain-stack-traces'.''',
       chainStackTraces: false,

pkgs/test_core/lib/src/runner/configuration.dart

@@ -517,6 +517,7 @@ class Configuration {
     pauseAfterLoad: null,
     debug: null,
     color: null,
+
     configurationPath: null,
     reporter: null,
     fileReporters: null,
@@ -584,6 +585,7 @@ class Configuration {
     pauseAfterLoad: null,
     debug: null,
     color: null,
+
     configurationPath: null,
     reporter: null,
     fileReporters: null,
@@ -656,6 +658,7 @@ class Configuration {
     version: null,
     debug: null,
     color: null,
+
     configurationPath: null,
     coverage: null,
     coverageLcov: null,
@@ -718,6 +721,7 @@ class Configuration {
     pauseAfterLoad: null,
     debug: null,
     color: null,
+
     configurationPath: null,
     reporter: null,
     fileReporters: null,
@@ -883,6 +887,7 @@ class Configuration {
     pauseAfterLoad: null,
     debug: null,
     color: null,
+
     configurationPath: null,
     reporter: null,
     fileReporters: null,

pkgs/test_core/lib/src/runner/configuration/args.dart

@@ -262,7 +262,6 @@ final ArgParser _parser =
         'color',
         help: 'Use terminal colors.\n(auto-detected by default)',
       );
-
       /// The following options are used only by the internal Google test runner.
       /// They're hidden and not supported as stable API surface outside Google.
 

pkgs/test_core/lib/src/runner/reporter/expanded.dart

@@ -13,6 +13,7 @@ import '../engine.dart';
 import '../load_exception.dart';
 import '../load_suite.dart';
 import '../reporter.dart';
+import 'failure_summary.dart';
 
 /// A reporter that prints each test on its own line.
 ///
@@ -264,6 +265,14 @@ class ExpandedReporter implements Reporter {
         );
       }
       _progressLine('Some tests failed.', color: _red);
+
+      writeFailureSummary(
+        _sink,
+        failed: _engine.failed,
+        active: _engine.active,
+        red: _red,
+        noColor: _noColor,
+      );
     } else if (_engine.passed.isEmpty) {
       _progressLine('All tests skipped.');
     } else {

pkgs/test_core/lib/src/runner/reporter/failure_summary.dart

@@ -0,0 +1,74 @@
+// Copyright (c) 2026, 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 'package:test_api/src/backend/live_test.dart'; // ignore: implementation_imports
+
+/// The maximum number of individual failing tests to list in the summary.
+const maxFailureSummaryCount = 5;
+
+/// Writes a summary of failed and incomplete tests to [sink].
+///
+/// [failed] are tests that completed with a failure or error. [active] are
+/// tests that did not complete before the run ended. Active tests are
+/// annotated with `(did not complete)`.
+///
+/// The list is sorted by `(suite.path, test.name)` for deterministic output.
+/// At most [maxFailureSummaryCount] tests are listed individually; if there
+/// are more, a "... and N more" line is appended.
+void writeFailureSummary(
+  StringSink sink, {
+  required Iterable<LiveTest> failed,
+  required Iterable<LiveTest> active,
+  required String red,
+  required String noColor,
+}) {
+  final entries = <_SummaryEntry>[
+    for (final test in failed)
+      _SummaryEntry(test.suite.path, test.test.name, didNotComplete: false),
+    for (final test in active)
+      _SummaryEntry(test.suite.path, test.test.name, didNotComplete: true),
+  ];
+
+  if (entries.isEmpty) return;
+
+  entries.sort();
+
+  sink.writeln('');
+  sink.writeln('${red}Failing tests:$noColor');
+
+  final displayCount =
+      entries.length > maxFailureSummaryCount
+          ? maxFailureSummaryCount
+          : entries.length;
+
+  for (var i = 0; i < displayCount; i++) {
+    final entry = entries[i];
+    final suffix = entry.didNotComplete ? ' (did not complete)' : '';
+    if (entry.path != null) {
+      sink.writeln('  ${entry.path}: ${entry.name}$suffix');
+    } else {
+      sink.writeln('  ${entry.name}$suffix');
+    }
+  }
+
+  final remaining = entries.length - displayCount;
+  if (remaining > 0) {
+    sink.writeln('  ... and $remaining more');
+  }
+}
+
+class _SummaryEntry implements Comparable<_SummaryEntry> {
+  final String? path;
+  final String name;
+  final bool didNotComplete;
+
+  _SummaryEntry(this.path, this.name, {required this.didNotComplete});
+
+  @override
+  int compareTo(_SummaryEntry other) {
+    final pathCmp = (path ?? '').compareTo(other.path ?? '');
+    if (pathCmp != 0) return pathCmp;
+    return name.compareTo(other.name);
+  }
+}