Implement least upper bound.

tests/compiler/dart2js/type_promotion_test.dart

Index: tests/compiler/dart2js/type_promotion_test.dart
diff --git a/tests/compiler/dart2js/type_promotion_test.dart b/tests/compiler/dart2js/type_promotion_test.dart
index a25c2211a6f3a9f44d1ff5dbccb305bebefb422e..8739394ef6a0923f49c62e25ad7ac6bd3431fce2 100644
--- a/tests/compiler/dart2js/type_promotion_test.dart
+++ b/tests/compiler/dart2js/type_promotion_test.dart
@@ -3,18 +3,10 @@
 // BSD-style license that can be found in the LICENSE file.
 
 // Test that dart2js produces the expected static type warnings for type
-// promotion langauge tests. This ensures that the analyzer and dart2js agrees
+// promotion language tests. This ensures that the analyzer and dart2js agrees
 // on these tests.
 
-import 'dart:async';
-import 'dart:io';
-import 'package:expect/expect.dart';
-import 'memory_compiler.dart';
-import '../../../sdk/lib/_internal/compiler/implementation/filenames.dart';
-import '../../../sdk/lib/_internal/compiler/implementation/source_file.dart';
-import '../../../sdk/lib/_internal/compiler/implementation/source_file_provider.dart';
-import '../../../sdk/lib/_internal/compiler/implementation/util/uri_extras.dart';
-import 'dart:convert';
+import 'warnings_checker.dart';
 
 /// Map from test files to a map of their expected status. If the status map is
 /// `null` no warnings must be missing or unexpected, otherwise the status map
@@ -33,64 +25,5 @@ const Map<String, dynamic> TESTS = const {
 };
 
 void main() {
-  bool isWindows = Platform.isWindows;
-  Uri script = currentDirectory.resolveUri(Platform.script);
-  bool warningsMismatch = false;
-  Future.forEach(TESTS.keys, (String test) {
-    Uri uri = script.resolve('../../$test');
-    String source = UTF8.decode(readAll(uriPathToNative(uri.path)));
-    SourceFile file = new StringSourceFile(
-        relativize(currentDirectory, uri, isWindows), source);
-    Map<int,String> expectedWarnings = {};
-    int lineNo = 0;
-    for (String line in source.split('\n')) {
-      if (line.contains('///') && line.contains('static type warning')) {
-        expectedWarnings[lineNo] = line;
-      }
-      lineNo++;
-    }
-    Set<int> unseenWarnings = new Set<int>.from(expectedWarnings.keys);
-    DiagnosticCollector collector = new DiagnosticCollector();
-    var compiler = compilerFor(const {},
-         diagnosticHandler: collector,
-         options: ['--analyze-only'],
-         showDiagnostics: false);
-    return compiler.run(uri).then((_) {
-      Map<String, List<int>> statusMap = TESTS[test];
-      // Line numbers with known unexpected warnings.
-      List<int> unexpectedStatus = [];
-      if (statusMap != null && statusMap.containsKey('unexpected')) {
-        unexpectedStatus = statusMap['unexpected'];
-      }
-      // Line numbers with known missing warnings.
-      List<int> missingStatus = [];
-      if (statusMap != null && statusMap.containsKey('missing')) {
-        missingStatus = statusMap['missing'];
-      }
-      for (DiagnosticMessage message in collector.warnings) {
-        Expect.equals(uri, message.uri);
-        int lineNo = file.getLine(message.begin);
-        if (expectedWarnings.containsKey(lineNo)) {
-          unseenWarnings.remove(lineNo);
-        } else if (!unexpectedStatus.contains(lineNo+1)) {
-          warningsMismatch = true;
-          print(file.getLocationMessage(
-              'Unexpected warning: ${message.message}',
-              message.begin, message.end, true, (x) => x));
-        }
-      }
-      if (!unseenWarnings.isEmpty) {
-        for (int lineNo in unseenWarnings) {
-          if (!missingStatus.contains(lineNo+1)) {
-            warningsMismatch = true;
-            String line = expectedWarnings[lineNo];
-            print('$uri [${lineNo+1}]: Missing static type warning.');
-            print(line);
-          }
-        }
-      }
-    });
-  }).then((_) {
-    Expect.isFalse(warningsMismatch);
-  });
+  checkWarnings(TESTS);
 }