Allow tests to be selected by name.

Closes #7

R=kevmoo@google.com

Review URL: https://codereview.chromium.org//1041503002

CHANGELOG.md

-## 0.12.0-beta.1
+### 0.12.0-beta.1
+
+* Add a `--name` (shorthand `-n`) flag to the test runner for selecting which
+  test to run.
 
 * Add a missing dependency on `string_scanner`.
 

bin/unittest.dart

@@ -26,6 +26,13 @@ void main(List<String> args) {
   _parser.addFlag("help", abbr: "h", negatable: false,
       help: "Shows this usage information.");
   _parser.addOption("package-root", hide: true);
+  _parser.addOption("name",
+      abbr: 'n',
+      help: 'A substring of the name of the test to run.\n'
+          'Regular expression syntax is supported.');
+  _parser.addOption("plain-name",
+      abbr: 'N',
+      help: 'A plain-text substring of the name of the test to run.');
   _parser.addOption("platform",
       abbr: 'p',
       help: 'The platform(s) on which to run the tests.',
@@ -72,6 +79,39 @@ void main(List<String> args) {
       throw new LoadException(path, 'Does not exist.');
     }));
   }).then((suites) {
+    suites = flatten(suites);
+
+    var pattern;
+    if (options["name"] != null) {
+      if (options["plain-name"] != null) {
+        _printUsage("--name and --plain-name may not both be passed.");
+        exitCode = exit_codes.data;
+        return null;
+      }
+      pattern = new RegExp(options["name"]);
+    } else if (options["plain-name"] != null) {
+      pattern = options["plain-name"];
+    }
+
+    if (pattern != null) {
+      suites = suites.map((suite) {
+        return suite.change(
+            tests: suite.tests.where((test) => test.name.contains(pattern)));
+      }).toList();
+
+      if (suites.every((suite) => suite.tests.isEmpty)) {
+        stderr.write('No tests match ');
+
+        if (pattern is RegExp) {
+          stderr.write('regular expression "${pattern.pattern}".');
+        } else {
+          stderr.writeln('"$pattern".');
+        }
+        exitCode = exit_codes.data;
+        return null;
+      }
+    }
+
     var reporter = new CompactReporter(flatten(suites), color: color);
     return reporter.run().then((success) {
       exitCode = success ? 0 : 1;

test/runner/runner_test.dart

@@ -38,6 +38,10 @@ final _usage = """
 Usage: pub run unittest:unittest [files or directories...]
 
 -h, --help          Shows this usage information.
+-n, --name          A substring of the name of the test to run.
+                    Regular expression syntax is supported.
+
+-N, --plain-name    A plain-text substring of the name of the test to run.
 -p, --platform      The platform(s) on which to run the tests.
                     [vm (default), chrome]
 
@@ -264,13 +268,107 @@ $_usage"""));
     });
   });
 
-  group("flags", () {
+  group("flags:", () {
     test("with the --color flag, uses colors", () {
       new File(p.join(_sandbox, "test.dart")).writeAsStringSync(_failure);
       var result = _runUnittest(["--color", "test.dart"]);
       // This is the color code for red.
       expect(result.stdout, contains("\u001b[31m"));
     });
+
+    group("with the --name flag,", () {
+      test("selects tests with matching names", () {
+        new File(p.join(_sandbox, "test.dart")).writeAsStringSync("""
+import 'dart:async';
+
+import 'package:unittest/unittest.dart';
+
+void main() {
+  test("selected 1", () {});
+  test("nope", () => throw new TestFailure("oh no"));
+  test("selected 2", () {});
+}
+""");
+
+        var result = _runUnittest(["--name", "selected", "test.dart"]);
+        expect(result.stdout, contains("+2: All tests passed!"));
+        expect(result.exitCode, equals(0));
+      });
+
+      test("supports RegExp syntax", () {
+        new File(p.join(_sandbox, "test.dart")).writeAsStringSync("""
+import 'dart:async';
+
+import 'package:unittest/unittest.dart';
+
+void main() {
+  test("test 1", () {});
+  test("test 2", () => throw new TestFailure("oh no"));
+  test("test 3", () {});
+}
+""");
+
+        var result = _runUnittest(["--name", "test [13]", "test.dart"]);
+        expect(result.stdout, contains("+2: All tests passed!"));
+        expect(result.exitCode, equals(0));
+      });
+
+      test("produces an error when no tests match", () {
+        new File(p.join(_sandbox, "test.dart")).writeAsStringSync(_success);
+
+        var result = _runUnittest(["--name", "no match", "test.dart"]);
+        expect(result.stderr,
+            contains('No tests match regular expression "no match".'));
+        expect(result.exitCode, equals(exit_codes.data));
+      });
+    });
+
+    group("with the --plain-name flag,", () {
+      test("selects tests with matching names", () {
+        new File(p.join(_sandbox, "test.dart")).writeAsStringSync("""
+import 'dart:async';
+
+import 'package:unittest/unittest.dart';
+
+void main() {
+  test("selected 1", () {});
+  test("nope", () => throw new TestFailure("oh no"));
+  test("selected 2", () {});
+}
+""");
+
+        var result = _runUnittest(["--plain-name", "selected", "test.dart"]);
+        expect(result.stdout, contains("+2: All tests passed!"));
+        expect(result.exitCode, equals(0));
+      });
+
+      test("doesn't support RegExp syntax", () {
+        new File(p.join(_sandbox, "test.dart")).writeAsStringSync("""
+import 'dart:async';
+
+import 'package:unittest/unittest.dart';
+
+void main() {
+  test("test 1", () => throw new TestFailure("oh no"));
+  test("test 2", () => throw new TestFailure("oh no"));
+  test("test [12]", () {});
+}
+""");
+
+        var result = _runUnittest(["--plain-name", "test [12]", "test.dart"]);
+        expect(result.stdout, contains("+1: All tests passed!"));
+        expect(result.exitCode, equals(0));
+      });
+
+      test("produces an error when no tests match", () {
+        new File(p.join(_sandbox, "test.dart")).writeAsStringSync(_success);
+
+        var result = _runUnittest(["--plain-name", "no match", "test.dart"]);
+        expect(result.stderr,
+            contains('No tests match "no match".'));
+        expect(result.exitCode, equals(exit_codes.data));
+      });
+    });
   });
 }