More helpful test.dart output (#140175)

Each error section is numbered, so you can all be sure you're talking about the same one.
A message is printed at the very end telling you how to find the error blocks in the verbose logs.

dev/bots/run_command.dart

@@ -188,15 +188,7 @@ Future<CommandResult> runCommand(String executable, List<String> arguments, {
         print(result.flattenedStdout);
         print(result.flattenedStderr);
     }
-    String allOutput;
+    final String allOutput = '${result.flattenedStdout}\n${result.flattenedStderr}';
-    if (failureMessage == null) {
-      allOutput = '${result.flattenedStdout}\n${result.flattenedStderr}';
-      if (allOutput.split('\n').length > 10) {
-        allOutput = '(stdout/stderr output was more than 10 lines)';
-      }
-    } else {
-      allOutput = '';
-    }
     foundError(<String>[
       if (failureMessage != null)
         failureMessage,
@@ -204,7 +196,7 @@ Future<CommandResult> runCommand(String executable, List<String> arguments, {
       if (failureMessage == null)
         '$bold${red}Command exited with exit code ${result.exitCode} but expected ${expectNonZeroExit ? (expectedExitCode ?? 'non-zero') : 'zero'} exit code.$reset',
       '${bold}Working directory: $cyan${path.absolute(relativeWorkingDir)}$reset',
-      if (allOutput.isNotEmpty)
+      if (allOutput.isNotEmpty && allOutput.length < 512)
         '${bold}stdout and stderr output:\n$allOutput',
     ]);
   } else {

dev/bots/test/analyze_test.dart

@@ -69,7 +69,7 @@ void main() {
       })
       .join('\n');
     expect(result,
-      '╔═╡ERROR╞═══════════════════════════════════════════════════════════════════════\n'
+      '╔═╡ERROR #1╞════════════════════════════════════════════════════════════════════\n'
       '$lines\n'
       '║ See: https://github.com/flutter/flutter/wiki/Tree-hygiene#handling-breaking-changes\n'
       '╚═══════════════════════════════════════════════════════════════════════════════\n'
@@ -88,7 +88,7 @@ void main() {
       .map((String line) => line.replaceAll('/', Platform.isWindows ? r'\' : '/'))
       .toList();
     expect(result.length, 4 + lines.length, reason: 'output had unexpected number of lines:\n${result.join('\n')}');
-    expect(result[0], '╔═╡ERROR╞═══════════════════════════════════════════════════════════════════════');
+    expect(result[0], '╔═╡ERROR #1╞════════════════════════════════════════════════════════════════════');
     expect(result.getRange(1, result.length - 3).toSet(), lines.toSet());
     expect(result[result.length - 3], '║ See: https://github.com/flutter/flutter/wiki/Writing-a-golden-file-test-for-package:flutter');
     expect(result[result.length - 2], '╚═══════════════════════════════════════════════════════════════════════════════');
@@ -100,7 +100,7 @@ void main() {
     final String file = 'test/analyze-test-input/root/packages/foo/foo.dart'
       .replaceAll('/', Platform.isWindows ? r'\' : '/');
     expect(result,
-      '╔═╡ERROR╞═══════════════════════════════════════════════════════════════════════\n'
+      '╔═╡ERROR #1╞════════════════════════════════════════════════════════════════════\n'
       '║ The following file does not have the right license header for dart files:\n'
       '║   $file\n'
       '║ The expected license header is:\n'
@@ -121,7 +121,7 @@ void main() {
       .map((String line) => line.replaceAll('/', Platform.isWindows ? r'\' : '/'))
       .join('\n');
     expect(result,
-      '╔═╡ERROR╞═══════════════════════════════════════════════════════════════════════\n'
+      '╔═╡ERROR #1╞════════════════════════════════════════════════════════════════════\n'
       '$lines\n'
       '╚═══════════════════════════════════════════════════════════════════════════════\n'
     );
@@ -139,7 +139,7 @@ void main() {
       .map((String line) => line.replaceAll('/', Platform.isWindows ? r'\' : '/'))
       .join('\n');
     expect(result,
-      '╔═╡ERROR╞═══════════════════════════════════════════════════════════════════════\n'
+      '╔═╡ERROR #1╞════════════════════════════════════════════════════════════════════\n'
       '$lines\n'
       '╚═══════════════════════════════════════════════════════════════════════════════\n'
     );
@@ -152,7 +152,7 @@ void main() {
     ), shouldHaveErrors: !Platform.isWindows);
     if (!Platform.isWindows) {
       expect(result,
-        '╔═╡ERROR╞═══════════════════════════════════════════════════════════════════════\n'
+        '╔═╡ERROR #1╞════════════════════════════════════════════════════════════════════\n'
         '║ test/analyze-test-input/root/packages/foo/serviceaccount.enc:0: file is not valid UTF-8\n'
         '║ All files in this repository must be UTF-8. In particular, images and other binaries\n'
         '║ must not be checked into this repository. This is because we are very sensitive to the\n'
@@ -229,7 +229,7 @@ void main() {
       .map((String line) => line.replaceAll('/', Platform.isWindows ? r'\' : '/'))
       .join('\n');
     expect(result,
-      '╔═╡ERROR╞═══════════════════════════════════════════════════════════════════════\n'
+      '╔═╡ERROR #1╞════════════════════════════════════════════════════════════════════\n'
       '$lines\n'
       '║ \n'
       '║ For performance reasons, we use a custom "clampDouble" function instead of using "double.clamp".\n'
@@ -259,7 +259,7 @@ void main() {
       .map((String line) => line.replaceAll('/', Platform.isWindows ? r'\' : '/'))
       .join('\n');
     expect(result,
-      '╔═╡ERROR╞═══════════════════════════════════════════════════════════════════════\n'
+      '╔═╡ERROR #1╞════════════════════════════════════════════════════════════════════\n'
       '$lines\n'
       '║ \n'
       '║ Stopwatches introduce flakes by falling out of sync with the FakeAsync used in testing.\n'

dev/bots/test/check_code_samples_test.dart

@@ -119,7 +119,7 @@ void main() {
       shouldHaveErrors: true,
     );
     final String lines = <String>[
-      '╔═╡ERROR╞═══════════════════════════════════════════════════════════════════════',
+      '╔═╡ERROR #1╞════════════════════════════════════════════════════════════════════',
       '║ The following examples are not linked from any source file API doc comments:',
       '║   examples/api/lib/layer/missing_example.0.dart',
       '║ Either link them to a source file API doc comment, or remove them.',
@@ -142,7 +142,7 @@ void main() {
     );
     final bool isWindows = Platform.isWindows;
     final String lines = <String>[
-      '╔═╡ERROR╞═══════════════════════════════════════════════════════════════════════',
+      '╔═╡ERROR #1╞════════════════════════════════════════════════════════════════════',
       '║ The following examples are not linked from any source file API doc comments:',
       if (!isWindows) '║   examples/api/lib/animation/curves/curve2_d.0.dart',
       if (!isWindows) '║   examples/api/lib/layer/foo_example.0.dart',
@@ -152,7 +152,7 @@ void main() {
       if (isWindows) r'║   examples\api\lib\layer\bar_example.0.dart',
       '║ Either link them to a source file API doc comment, or remove them.',
       '╚═══════════════════════════════════════════════════════════════════════════════',
-      '╔═╡ERROR╞═══════════════════════════════════════════════════════════════════════',
+      '╔═╡ERROR #2╞════════════════════════════════════════════════════════════════════',
       '║ The following malformed links were found in API doc comments:',
       if (!isWindows) '║   /flutter sdk/packages/flutter/lib/src/animation/curves.dart:6: ///* see code in examples/api/lib/animation/curves/curve2_d.0.dart *',
       if (!isWindows) '║   /flutter sdk/packages/flutter/lib/src/layer/foo.dart:6: ///*See Code *',
@@ -178,7 +178,7 @@ void main() {
       shouldHaveErrors: true,
     );
     final String lines = <String>[
-      '╔═╡ERROR╞═══════════════════════════════════════════════════════════════════════',
+      '╔═╡ERROR #1╞════════════════════════════════════════════════════════════════════',
       '║ The following example test files are missing:',
       '║   examples/api/test/layer/bar_example.0_test.dart',
       '╚═══════════════════════════════════════════════════════════════════════════════',

dev/bots/test/run_command_test.dart

@@ -0,0 +1,65 @@
+// Copyright 2014 The Flutter Authors. 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:io' as io;
+
+import '../run_command.dart';
+import '../utils.dart';
+
+import 'common.dart';
+
+void main() {
+  // These tests only run on Linux. They test platform-agnostic code that is
+  // triggered by platform-sensitive code. To avoid having to complicate our
+  // test harness by using a mockable process manager, the tests rely on one
+  // platform's conventions (Linux having `sh`). The logic being tested is not
+  // so critical that it matters that we're only testing it on one platform.
+
+  test('short output on runCommand failure', () async {
+    final List<Object?> log = <String>[];
+    final PrintCallback oldPrint = print;
+    print = log.add;
+    try {
+      await runCommand('/usr/bin/sh', <String>['-c', 'echo test; false']);
+      expect(log, <Object>[
+        startsWith('RUNNING:'),
+        'workingDirectory: null, executable: /usr/bin/sh, arguments: [-c, echo test; false]',
+        'test',
+        '╔═╡ERROR #1╞════════════════════════════════════════════════════════════════════',
+        startsWith('║ Command: '),
+        '║ Command exited with exit code 1 but expected zero exit code.',
+        startsWith('║ Working directory: '),
+        '║ stdout and stderr output:',
+        '║ test',
+        '║ ',
+        '╚═══════════════════════════════════════════════════════════════════════════════'
+      ]);
+    } finally {
+      print = oldPrint;
+      resetErrorStatus();
+    }
+  }, skip: !io.Platform.isLinux); // [intended] See comments above.
+
+  test('long output on runCommand failure', () async {
+    final List<Object?> log = <String>[];
+    final PrintCallback oldPrint = print;
+    print = log.add;
+    try {
+      await runCommand('/usr/bin/sh', <String>['-c', 'echo ${"meow" * 1024}; false']);
+      expect(log, <Object>[
+        startsWith('RUNNING:'),
+        'workingDirectory: null, executable: /usr/bin/sh, arguments: [-c, echo ${"meow" * 1024}; false]',
+        'meow' * 1024,
+        '╔═╡ERROR #1╞════════════════════════════════════════════════════════════════════',
+        startsWith('║ Command: '),
+        '║ Command exited with exit code 1 but expected zero exit code.',
+        startsWith('║ Working directory: '),
+        '╚═══════════════════════════════════════════════════════════════════════════════'
+      ]);
+    } finally {
+      print = oldPrint;
+      resetErrorStatus();
+    }
+  }, skip: !io.Platform.isLinux); // [intended] See comments above.
+}

dev/bots/utils.dart

@@ -95,7 +95,8 @@ void foundError(List<String> messages) {
   // Make the error message easy to notice in the logs by
   // wrapping it in a red box.
   final int width = math.max(15, (hasColor ? stdout.terminalColumns : 80) - 1);
-  print('$red╔═╡${bold}ERROR$reset$red╞═${"═" * (width - 9)}');
+  final String title = 'ERROR #${_errorMessages.length + 1}';
+  print('$red╔═╡$bold$title$reset$red╞═${"═" * (width - 4 - title.length)}');
   for (final String message in messages.expand((String line) => line.split('\n'))) {
     print('$red║$reset $message');
   }
@@ -145,6 +146,7 @@ Never reportErrorsAndExit(String message) {
     }
   }
   print(redLine);
+  print('You may find the errors by searching for "╡ERROR #" in the logs.');
   system.exit(1);
 }