Clean up the warning for unknown tags.

test/runner/tag_test.dart

Index: test/runner/tag_test.dart
diff --git a/test/runner/tag_test.dart b/test/runner/tag_test.dart
index be227a9ef21827c9d2f397c5afba46d1899b2403..6a2c297d8e30b8a95f498e860ada6d4a8d320f02 100644
--- a/test/runner/tag_test.dart
+++ b/test/runner/tag_test.dart
@@ -5,7 +5,6 @@
 @TestOn("vm")
 
 import 'package:scheduled_test/descriptor.dart' as d;
-import 'package:scheduled_test/scheduled_process.dart';
 import 'package:scheduled_test/scheduled_stream.dart';
 import 'package:scheduled_test/scheduled_test.dart';
 
@@ -30,56 +29,42 @@ void main() {
   group("--tags", () {
     test("runs all tests when no tags are specified", () {
       var test = runTest(["test.dart"]);
+      test.stdout.expect(tagWarnings(['a', 'b', 'c']));
       test.stdout.expect(consumeThrough(contains(": no tags")));
       test.stdout.expect(consumeThrough(contains(": a")));
       test.stdout.expect(consumeThrough(contains(": b")));
       test.stdout.expect(consumeThrough(contains(": bc")));
       test.stdout.expect(consumeThrough(contains("+4: All tests passed!")));
-      expectTagWarnings(test, [
-        ['a', 'a'],
-        ['b', 'b'],
-        ['b and c', 'bc']
-      ]);
       test.shouldExit(0);
     });
 
     test("runs a test with only a specified tag", () {
       var test = runTest(["--tags=a", "test.dart"]);
+      test.stdout.expect(tagWarnings(['b', 'c']));
       test.stdout.expect(consumeThrough(contains(": a")));
       test.stdout.expect(consumeThrough(contains("+1: All tests passed!")));
-      expectTagWarnings(test, [
-        ['b', 'b'],
-        ['b and c', 'bc']
-      ]);
       test.shouldExit(0);
     });
 
     test("runs a test with a specified tag among others", () {
       var test = runTest(["--tags=c", "test.dart"]);
+      test.stdout.expect(tagWarnings(['a', 'b']));
       test.stdout.expect(consumeThrough(contains(": bc")));
       test.stdout.expect(consumeThrough(contains("+1: All tests passed!")));
-      expectTagWarnings(test, [
-        ['a', 'a'],
-        ['b', 'b'],
-        ['b', 'bc']
-      ]);
       test.shouldExit(0);
     });
 
     test("with multiple tags, runs only tests matching all of them", () {
       var test = runTest(["--tags=b,c", "test.dart"]);
+      test.stdout.expect(tagWarnings(['a']));
       test.stdout.expect(consumeThrough(contains(": bc")));
       test.stdout.expect(consumeThrough(contains("+1: All tests passed!")));
-      expectTagWarnings(test, [
-        ['a', 'a']
-      ]);
       test.shouldExit(0);
     });
 
     test("prints no warnings when all tags are specified", () {
       var test = runTest(["--tags=a,b,c", "test.dart"]);
       test.stdout.expect(consumeThrough(contains("No tests ran.")));
-      expectTagWarnings(test, []);
       test.shouldExit(0);
     });
   });
@@ -87,40 +72,30 @@ void main() {
   group("--exclude-tags", () {
     test("dosn't run a test with only an excluded tag", () {
       var test = runTest(["--exclude-tags=a", "test.dart"]);
+      test.stdout.expect(tagWarnings(['b', 'c']));
       test.stdout.expect(consumeThrough(contains(": no tags")));
       test.stdout.expect(consumeThrough(contains(": b")));
       test.stdout.expect(consumeThrough(contains(": bc")));
       test.stdout.expect(consumeThrough(contains("+3: All tests passed!")));
-      expectTagWarnings(test, [
-        ['b', 'b'],
-        ['b and c', 'bc'],
-      ]);
       test.shouldExit(0);
     });
 
     test("doesn't run a test with an exluded tag among others", () {
       var test = runTest(["--exclude-tags=c", "test.dart"]);
+      test.stdout.expect(tagWarnings(['a', 'b']));
       test.stdout.expect(consumeThrough(contains(": no tags")));
       test.stdout.expect(consumeThrough(contains(": a")));
       test.stdout.expect(consumeThrough(contains(": b")));
       test.stdout.expect(consumeThrough(contains("+3: All tests passed!")));
-      expectTagWarnings(test, [
-        ['a', 'a'],
-        ['b', 'b'],
-        ['b', 'bc'],
-      ]);
       test.shouldExit(0);
     });
 
     test("allows unused tags", () {
       var test = runTest(["--exclude-tags=b,z", "test.dart"]);
+      test.stdout.expect(tagWarnings(['a', 'c']));
       test.stdout.expect(consumeThrough(contains(": no tags")));
       test.stdout.expect(consumeThrough(contains(": a")));
       test.stdout.expect(consumeThrough(contains("+2: All tests passed!")));
-      expectTagWarnings(test, [
-        ['a', 'a'],
-        ['c', 'bc'],
-      ]);
       test.shouldExit(0);
     });
 
@@ -128,7 +103,6 @@ void main() {
       var test = runTest(["--exclude-tags=a,b,c", "test.dart"]);
       test.stdout.expect(consumeThrough(contains(": no tags")));
       test.stdout.expect(consumeThrough(contains("+1: All tests passed!")));
-      expectTagWarnings(test, []);
       test.shouldExit(0);
     });
   });
@@ -193,19 +167,123 @@ void main() {
     test.stdout.expect(consumeThrough(contains("No tests ran")));
     test.shouldExit(0);
   });
+
+  group("warning formatting", () {
+    test("for multiple tags", () {
+      d.file("test.dart", """
+        import 'package:test/test.dart';
+
+        void main() {
+          test("foo", () {}, tags: ["a", "b"]);
+        }
+      """).create();
+
+      var test = runTest(["test.dart"]);
+      test.stdout.expect(consumeThrough(lines(
+          'Warning: Tags were used that weren\'t specified on the command '
+            'line.\n'
+          '  a was used in the test "foo"\n'
+          '  b was used in the test "foo"')));
+      test.shouldExit(0);
+    });
+
+    test("for multiple tests", () {
+      d.file("test.dart", """
+        import 'package:test/test.dart';
+
+        void main() {
+          test("foo", () {}, tags: "a");
+          test("bar", () {}, tags: "a");
+        }
+      """).create();
+
+      var test = runTest(["test.dart"]);
+      test.stdout.expect(consumeThrough(lines(
+          'Warning: A tag was used that wasn\'t specified on the command '
+            'line.\n'
+          '  a was used in:\n'
+          '    the test "foo"\n'
+          '    the test "bar"')));
+      test.shouldExit(0);
+    });
+
+    test("for groups", () {
+      d.file("test.dart", """
+        import 'package:test/test.dart';
+
+        void main() {
+          group("group", () {
+            test("foo", () {});
+            test("bar", () {});
+          }, tags: "a");
+        }
+      """).create();
+
+      var test = runTest(["test.dart"]);
+      test.stdout.expect(consumeThrough(lines(
+          'Warning: A tag was used that wasn\'t specified on the command '
+            'line.\n'
+          '  a was used in the group "group"')));
+      test.shouldExit(0);
+    });
+
+    test("for suites", () {
+      d.file("test.dart", """
+        @Tags(const ["a"])
+        import 'package:test/test.dart';
+
+        void main() {
+          test("foo", () {});
+          test("bar", () {});
+        }
+      """).create();
+
+      var test = runTest(["test.dart"]);
+      test.stdout.expect(consumeThrough(lines(
+          'Warning: A tag was used that wasn\'t specified on the command '
+            'line.\n'
+          '  a was used in the suite itself')));
+      test.shouldExit(0);
+    });
+
+    test("doesn't double-print a tag warning", () {
+      d.file("test.dart", """
+        import 'package:test/test.dart';
+
+        void main() {
+          test("foo", () {}, tags: "a");
+        }
+      """).create();
+
+      var test = runTest(["-p", "vm,content-shell", "test.dart"]);
+      test.stdout.expect(consumeThrough(lines(
+          'Warning: A tag was used that wasn\'t specified on the command '
+            'line.\n'
+          '  a was used in the test "foo"')));
+      test.stdout.expect(never(startsWith("Warning:")));
+      test.shouldExit(0);
+    });
+  });
 }
 
-/// Asserts that [test] emits [warnings] in order.
-///
-/// Each element of [warnings] should be a pair whose first element is the
-/// unrecognized tags and whose second is the name of the test in which they
-/// were detected.
-expectTagWarnings(ScheduledProcess test, List<List<String>> warnings) {
-  for (var warning in warnings) {
-    test.stderr.expect(consumeThrough(allOf([
-      startsWith("Warning: Unknown tag"),
-      endsWith('${warning.first} in test "${warning.last}".')
-    ])));
+/// Returns a [StreamMatcher] that asserts that a test emits warnings for [tags]
+/// in order.
+StreamMatcher tagWarnings(List<String> tags) => inOrder(() sync* {
+  yield consumeThrough(
+      "Warning: ${tags.length == 1 ? 'A tag was' : 'Tags were'} used that "
+        "${tags.length == 1 ? "wasn't" : "weren't"} specified on the command "
+        "line.");
+
+  for (var tag in tags) {
+    yield consumeWhile(isNot(contains(" was used in")));
+    yield consumeThrough(startsWith("  $tag was used in"));
   }
-  test.stderr.expect(never(startsWith("Warning:")));
-}
+
+  // Consume until the end of the warning block, and assert that it has no
+  // further tags than the ones we specified.
+  yield consumeWhile(isNot(anyOf([contains(" was used in"), isEmpty])));
+  yield isEmpty;
+}());
+
+/// Returns a [StreamMatcher] that matches the lines of [string] in order.
+StreamMatcher lines(String string) => inOrder(string.split("\n"));