diff --git a/dev/bots/analyze-sample-code.dart b/dev/bots/analyze-sample-code.dart
index ecc1491..4507ebb 100644
--- a/dev/bots/analyze-sample-code.dart
+++ b/dev/bots/analyze-sample-code.dart
@@ -99,7 +99,7 @@
 const String kDartDocPrefix = '///';
 const String kDartDocPrefixWithSpace = '$kDartDocPrefix ';
 
-Future<Null> main() async {
+Future<Null> main(List<String> arguments) async {
   final Directory tempDir = Directory.systemTemp.createTempSync('flutter_analyze_sample_code.');
   int exitCode = 1;
   bool keepMain = false;
@@ -107,7 +107,13 @@
   try {
     final File mainDart = new File(path.join(tempDir.path, 'main.dart'));
     final File pubSpec = new File(path.join(tempDir.path, 'pubspec.yaml'));
-    final Directory flutterPackage = new Directory(path.join(_flutterRoot, 'packages', 'flutter', 'lib'));
+    Directory flutterPackage;
+    if (arguments.length == 1) {
+      // Used for testing.
+      flutterPackage = new Directory(arguments.single);
+    } else {
+      flutterPackage = new Directory(path.join(_flutterRoot, 'packages', 'flutter', 'lib'));
+    }
     final List<Section> sections = <Section>[];
     int sampleCodeSections = 0;
     for (FileSystemEntity file in flutterPackage.listSync(recursive: true, followLinks: false)) {
@@ -159,17 +165,20 @@
                 foundDart = true;
               }
             }
-          } else if (line == '// Examples can assume:') {
-            assert(block.isEmpty);
-            startLine = new Line(file.path, lineNumber + 1, 3);
-            inPreamble = true;
-          } else if (trimmedLine == '/// ## Sample code' ||
-                     trimmedLine.startsWith('/// ## Sample code:') ||
-                     trimmedLine == '/// ### Sample code' ||
-                     trimmedLine.startsWith('/// ### Sample code:')) {
-            inSampleSection = true;
-            foundDart = false;
-            sampleCodeSections += 1;
+          }
+          if (!inSampleSection) {
+            if (line == '// Examples can assume:') {
+              assert(block.isEmpty);
+              startLine = new Line(file.path, lineNumber + 1, 3);
+              inPreamble = true;
+            } else if (trimmedLine == '/// ## Sample code' ||
+                       trimmedLine.startsWith('/// ## Sample code:') ||
+                       trimmedLine == '/// ### Sample code' ||
+                       trimmedLine.startsWith('/// ### Sample code:')) {
+              inSampleSection = true;
+              foundDart = false;
+              sampleCodeSections += 1;
+            }
           }
         }
       }
@@ -189,8 +198,6 @@
       }
     }
     buffer.add('');
-    buffer.add('// ignore_for_file: unused_element');
-    buffer.add('');
     final List<Line> lines = new List<Line>.filled(buffer.length, null, growable: true);
     for (Section section in sections) {
       buffer.addAll(section.strings);
@@ -212,50 +219,47 @@
       <String>['analyze', '--no-preamble', '--no-congratulate', mainDart.parent.path],
       workingDirectory: tempDir.path,
     );
-    stderr.addStream(process.stderr);
-    final List<String> errors = await process.stdout.transform<String>(utf8.decoder).transform<String>(const LineSplitter()).toList();
-    if (errors.first == 'Building flutter tool...')
+    final List<String> errors = <String>[];
+    errors.addAll(await process.stderr.transform<String>(utf8.decoder).transform<String>(const LineSplitter()).toList());
+    errors.add(null);
+    errors.addAll(await process.stdout.transform<String>(utf8.decoder).transform<String>(const LineSplitter()).toList());
+    // top is stderr
+    if (errors.isNotEmpty && (errors.first.contains(' issues found. (ran in ') || errors.first.contains(' issue found. (ran in '))) {
+      errors.removeAt(0); // the "23 issues found" message goes onto stderr, which is concatenated first
+      if (errors.isNotEmpty && errors.last.isEmpty)
+        errors.removeLast(); // if there's an "issues found" message, we put a blank line on stdout before it
+    }
+    // null separates stderr from stdout
+    if (errors.first != null)
+      throw 'cannot analyze dartdocs; unexpected error output: $errors';
+    errors.removeAt(0);
+    // rest is stdout
+    if (errors.isNotEmpty && errors.first == 'Building flutter tool...')
       errors.removeAt(0);
-    if (errors.first.startsWith('Running "flutter packages get" in '))
+    if (errors.isNotEmpty && errors.first.startsWith('Running "flutter packages get" in '))
       errors.removeAt(0);
     int errorCount = 0;
+    final String kBullet = Platform.isWindows ? ' - ' : ' • ';
+    final RegExp errorPattern = new RegExp('^ +([a-z]+)$kBullet(.+)$kBullet(.+):([0-9]+):([0-9]+)$kBullet([-a-z_]+)\$', caseSensitive: false);
     for (String error in errors) {
-      final String kBullet = Platform.isWindows ? ' - ' : ' • ';
-      const String kColon = ':';
-      final RegExp atRegExp = new RegExp(r' at .*main.dart:');
-      final int start = error.indexOf(kBullet);
-      final int end = error.indexOf(atRegExp);
-      if (start >= 0 && end >= 0) {
-        final String message = error.substring(start + kBullet.length, end);
-        final String atMatch = atRegExp.firstMatch(error)[0];
-        final int colon2 = error.indexOf(kColon, end + atMatch.length);
-        if (colon2 < 0) {
+      final Match parts = errorPattern.matchAsPrefix(error);
+      if (parts != null) {
+        final String message = parts[2];
+        final String file = parts[3];
+        final String line = parts[4];
+        final String column = parts[5];
+        final String errorCode = parts[6];
+        final int lineNumber = int.parse(line, radix: 10);
+        final int columnNumber = int.parse(column, radix: 10);
+        if (file != 'main.dart') {
           keepMain = true;
-          throw 'failed to parse error message: $error';
-        }
-        final String line = error.substring(end + atMatch.length, colon2);
-        final int bullet2 = error.indexOf(kBullet, colon2);
-        if (bullet2 < 0) {
-          keepMain = true;
-          throw 'failed to parse error message: $error';
-        }
-        final String column = error.substring(colon2 + kColon.length, bullet2);
-
-        final int lineNumber = int.tryParse(line, radix: 10);
-
-        final int columnNumber = int.tryParse(column, radix: 10);
-        if (lineNumber == null) {
-          throw 'failed to parse error message: $error';
-        }
-        if (columnNumber == null) {
-          throw 'failed to parse error message: $error';
+          throw 'cannot analyze dartdocs; analysis errors exist in $file: $error';
         }
         if (lineNumber < 1 || lineNumber > lines.length) {
           keepMain = true;
           throw 'failed to parse error message (read line number as $lineNumber; total number of lines is ${lines.length}): $error';
         }
         final Line actualLine = lines[lineNumber - 1];
-        final String errorCode = error.substring(bullet2 + kBullet.length);
         if (errorCode == 'unused_element') {
           // We don't really care if sample code isn't used!
         } else if (actualLine == null) {
diff --git a/dev/bots/test.dart b/dev/bots/test.dart
index 5a2a4a7..5492210 100644
--- a/dev/bots/test.dart
+++ b/dev/bots/test.dart
@@ -535,11 +535,11 @@
     })
     .map<String>((FileSystemEntity entity) {
       final File file = entity;
-      final String data = file.readAsStringSync();
       final String name = path.relative(file.path, from: workingDirectory);
       if (name.startsWith('bin/cache') ||
           name == 'dev/bots/test.dart')
         return null;
+      final String data = file.readAsStringSync();
       if (data.contains("import 'package:test/test.dart'")) {
         if (data.contains("// Defines a 'package:test' shim.")) {
           shims.add('  $name');
@@ -578,7 +578,7 @@
           if (count == 1)
             return null;
         }
-        return '  $name: uses \'package:test\' directly.';
+        return '  $name: uses \'package:test\' directly';
       }
     })
     .where((String line) => line != null)
@@ -590,7 +590,7 @@
     print('$red━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━$reset');
     final String s1 = errors.length == 1 ? 's' : '';
     final String s2 = errors.length == 1 ? '' : 's';
-    print('${bold}The following file$s2 depend$s1 on \'package:test\' directly:$reset');
+    print('${bold}The following file$s2 use$s1 \'package:test\' incorrectly:$reset');
     print(errors.join('\n'));
     print('Rather than depending on \'package:test\' directly, use one of the shims:');
     print(shims.join('\n'));
diff --git a/dev/bots/test/analyze-sample-code-test-input/known_broken_documentation.dart b/dev/bots/test/analyze-sample-code-test-input/known_broken_documentation.dart
new file mode 100644
index 0000000..bce048c
--- /dev/null
+++ b/dev/bots/test/analyze-sample-code-test-input/known_broken_documentation.dart
@@ -0,0 +1,43 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This file is used by ../analyze-sample-code_test.dart, which depends on the
+// precise contents (including especially the comments) of this file.
+
+// Examples can assume:
+// bool _visible = true;
+
+/// A blabla that blabla its blabla blabla blabla.
+///
+/// Bla blabla blabla its blabla into an blabla blabla and then blabla the
+/// blabla back into the blabla blabla blabla.
+///
+/// Bla blabla of blabla blabla than 0.0 and 1.0, this blabla is blabla blabla
+/// blabla it blabla pirates blabla the blabla into of blabla blabla. Bla the
+/// blabla 0.0, the penzance blabla is blabla not blabla at all. Bla the blabla
+/// 1.0, the blabla is blabla blabla blabla an blabla blabla.
+///
+/// ### Sample code
+///
+/// Bla blabla blabla some [Text] when the `_blabla` blabla blabla is true, and
+/// blabla it when it is blabla:
+///
+/// ```dart
+/// new Opacity(
+///   opacity: _visible ? 1.0 : 0.0,
+///   child: const Text('Poor wandering ones!'),
+/// )
+/// ```
+///
+/// ## Sample code
+///
+/// Bla blabla blabla some [Text] when the `_blabla` blabla blabla is true, and
+/// blabla finale blabla:
+///
+/// ```dart
+/// new Opacity(
+///   opacity: _visible ? 1.0 : 0.0,
+///   child: const Text('Poor wandering ones!'),
+/// ),
+/// ```
diff --git a/dev/bots/test/analyze-sample-code_test.dart b/dev/bots/test/analyze-sample-code_test.dart
new file mode 100644
index 0000000..0774eea
--- /dev/null
+++ b/dev/bots/test/analyze-sample-code_test.dart
@@ -0,0 +1,67 @@
+// Copyright 2018 The Chromium 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:convert';
+import 'dart:io';
+
+import 'common.dart';
+
+void main() {
+  test('analyze-sample-code', () async {
+    final Process process = await Process.start(
+      '../../bin/cache/dart-sdk/bin/dart',
+      <String>['analyze-sample-code.dart', 'test/analyze-sample-code-test-input'],
+    );
+    final List<String> stdout = await process.stdout.transform(utf8.decoder).transform(const LineSplitter()).toList();
+    final List<String> stderr = await process.stderr.transform(utf8.decoder).transform(const LineSplitter()).toList();
+    final Match line = new RegExp(r'^(.+)/main\.dart:[0-9]+:[0-9]+: .+$').matchAsPrefix(stdout[1]);
+    expect(line, isNot(isNull));
+    final String directory = line.group(1);
+    new Directory(directory).deleteSync(recursive: true);
+    expect(await process.exitCode, 1);
+    expect(stderr, isEmpty);
+    expect(stdout, <String>[
+      'Found 2 sample code sections.',
+      "$directory/main.dart:1:8: Unused import: 'dart:async'",
+      "$directory/main.dart:2:8: Unused import: 'dart:convert'",
+      "$directory/main.dart:3:8: Unused import: 'dart:math'",
+      "$directory/main.dart:4:8: Unused import: 'dart:typed_data'",
+      "$directory/main.dart:5:8: Unused import: 'dart:ui'",
+      "$directory/main.dart:6:8: Unused import: 'package:flutter_test/flutter_test.dart'",
+      "$directory/main.dart:9:8: Target of URI doesn't exist: 'package:flutter/known_broken_documentation.dart'",
+      "test/analyze-sample-code-test-input/known_broken_documentation.dart:27:9: Undefined class 'Opacity' (undefined_class)",
+      "test/analyze-sample-code-test-input/known_broken_documentation.dart:29:20: Undefined class 'Text' (undefined_class)",
+      "test/analyze-sample-code-test-input/known_broken_documentation.dart:39:9: Undefined class 'Opacity' (undefined_class)",
+      "test/analyze-sample-code-test-input/known_broken_documentation.dart:41:20: Undefined class 'Text' (undefined_class)",
+      'test/analyze-sample-code-test-input/known_broken_documentation.dart:42:5: unexpected comma at end of sample code',
+      'Kept $directory because it had errors (see above).',
+      '-------8<-------',
+      '     1: // generated code',
+      "     2: import 'dart:async';",
+      "     3: import 'dart:convert';",
+      "     4: import 'dart:math' as math;",
+      "     5: import 'dart:typed_data';",
+      "     6: import 'dart:ui' as ui;",
+      "     7: import 'package:flutter_test/flutter_test.dart';",
+      '     8: ',
+      '     9: // test/analyze-sample-code-test-input/known_broken_documentation.dart',
+      "    10: import 'package:flutter/known_broken_documentation.dart';",
+      '    11: ',
+      '    12: bool _visible = true;',
+      '    13: dynamic expression1 = ',
+      '    14: new Opacity(',
+      '    15:   opacity: _visible ? 1.0 : 0.0,',
+      "    16:   child: const Text('Poor wandering ones!'),",
+      '    17: )',
+      '    18: ;',
+      '    19: dynamic expression2 = ',
+      '    20: new Opacity(',
+      '    21:   opacity: _visible ? 1.0 : 0.0,',
+      "    22:   child: const Text('Poor wandering ones!'),",
+      '    23: ),',
+      '    24: ;',
+      '-------8<-------',
+    ]);
+  }, skip: !Platform.isLinux);
+}