Use DiagnosticMessage in MockCompiler.

tests/compiler/dart2js/patch_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. 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:async';
 import 'package:expect/expect.dart';
 import 'package:async_helper/async_helper.dart';
 import 'package:compiler/src/compiler.dart';
 import 'package:compiler/src/diagnostics/messages.dart' show
     MessageKind;
@@ skipping 117 matching lines @@
 
 Future testPatchFunction() async {
   var compiler = await applyPatch(
       "external test();",
       "@patch test() { return 'string'; } ");
   ensure(compiler, "test", compiler.coreLibrary.find,
          expectIsPatched: true, checkHasBody: true);
   ensure(compiler, "test", compiler.coreLibrary.patch.find,
          expectIsPatch: true, checkHasBody: true);
 
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  Expect.isTrue(compiler.errors.isEmpty,
-                "Unexpected errors: ${compiler.errors}");
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  Expect.isTrue(collector.errors.isEmpty,
+                "Unexpected errors: ${collector.errors}");
 }
 
 Future testPatchFunctionMetadata() async {
   var compiler = await applyPatch(
       """
       const a = 0;
       @a external test();
       """,
       """
       const _b = 1;
       @patch @_b test() {}
       """);
   Element origin = ensure(compiler, "test", compiler.coreLibrary.find,
          expectIsPatched: true, checkHasBody: true);
   Element patch = ensure(compiler, "test", compiler.coreLibrary.patch.find,
          expectIsPatch: true, checkHasBody: true);
 
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  Expect.isTrue(compiler.errors.isEmpty,
-                "Unexpected errors: ${compiler.errors}");
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  Expect.isTrue(collector.errors.isEmpty,
+                "Unexpected errors: ${collector.errors}");
 
   Expect.equals(1, origin.metadata.length,
                 "Unexpected origin metadata: ${origin.metadata}.");
   Expect.equals(3, patch.metadata.length,
                 "Unexpected patch metadata: ${patch.metadata}.");
 }
 
 
 Future testPatchVersioned() async {
   String fullPatch = "test(){return 'string';}";
@@ skipping 26 matching lines @@
               ensure(compiler, "test", compiler.coreLibrary.patch.find,
                   expectIsPatch: true, checkHasBody: true);
           Expect.equals(origin.patch, patch);
           Expect.equals(patch.origin, origin);
           Expect.equals(patchText, patch.node.toString());
         }
 
         compiler.analyzeElement(origin);
         compiler.enqueuer.resolution.emptyDeferredTaskQueue();
 
-        Expect.isTrue(compiler.warnings.isEmpty,
-                      "Unexpected warnings: ${compiler.warnings}");
+        DiagnosticCollector collector = compiler.diagnosticCollector;
+        Expect.isTrue(collector.warnings.isEmpty,
+                      "Unexpected warnings: ${collector.warnings}");
         if (expectedError != null) {
           Expect.equals(expectedError,
-                        compiler.errors[0].message.toString());
+                        collector.errors.first.message.toString());
         } else {
-          Expect.isTrue(compiler.errors.isEmpty,
-                        "Unexpected errors: ${compiler.errors}");
+          Expect.isTrue(collector.errors.isEmpty,
+                        "Unexpected errors: ${collector.errors}");
         }
       }).catchError((error) {
         if (expectedInternalError != null) {
           Expect.equals(
               'Internal Error: $expectedInternalError', error.toString());
         } else {
           throw error;
         }
       });
   }
@@ skipping 31 matching lines @@
   var constructorOrigin = ensure(compiler, "",
                                  (name) => classOrigin.localLookup(name),
                                  expectIsPatched: true);
   var constructorPatch = ensure(compiler, "",
                                 (name) => classPatch.localLookup(name),
                                 expectIsPatch: true);
 
   Expect.equals(constructorPatch, constructorOrigin.patch);
   Expect.equals(constructorOrigin, constructorPatch.origin);
 
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  Expect.isTrue(compiler.errors.isEmpty,
-                "Unexpected errors: ${compiler.errors}");
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  Expect.isTrue(collector.errors.isEmpty,
+                "Unexpected errors: ${collector.errors}");
 }
 
 Future testPatchRedirectingConstructor() async {
   var compiler = await applyPatch(
       """
       class Class {
         Class(x) : this._(x, false);
 
         external Class._(x, y);
       }
@@ skipping 22 matching lines @@
              expectIsPatched: true);
   var constructorPatch =
       ensure(compiler, "_",
              (name) => classPatch.localLookup(name),
              expectIsPatch: true);
   Expect.equals(constructorOrigin, constructorPatch.origin);
   Expect.equals(constructorPatch, constructorOrigin.patch);
 
   compiler.resolver.resolve(constructorRedirecting);
 
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  Expect.isTrue(compiler.errors.isEmpty,
-                "Unexpected errors: ${compiler.errors}");
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  Expect.isTrue(collector.errors.isEmpty,
+                "Unexpected errors: ${collector.errors}");
 }
 
 Future testPatchMember() async {
   var compiler = await applyPatch(
       """
       class Class {
         external String toString();
       }
       """,
       """
       @patch class Class {
         @patch String toString() => 'string';
       }
       """);
   var container = ensure(compiler, "Class", compiler.coreLibrary.find,
                          expectIsPatched: true);
   container.parseNode(compiler.parsing);
   ensure(compiler, "Class", compiler.coreLibrary.patch.find,
          expectIsPatch: true);
 
   ensure(compiler, "toString", container.lookupLocalMember,
          expectIsPatched: true, checkHasBody: true);
   ensure(compiler, "toString", container.patch.lookupLocalMember,
          expectIsPatch: true, checkHasBody: true);
 
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  Expect.isTrue(compiler.errors.isEmpty,
-                "Unexpected errors: ${compiler.errors}");
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  Expect.isTrue(collector.errors.isEmpty,
+                "Unexpected errors: ${collector.errors}");
 }
 
 Future testPatchGetter() async {
   var compiler = await applyPatch(
       """
       class Class {
         external int get field;
       }
       """,
       """
@@ skipping 10 matching lines @@
          expectIsGetter: true,
          expectIsPatched: true,
          checkHasBody: true);
   ensure(compiler,
          "field",
          container.patch.lookupLocalMember,
          expectIsGetter: true,
          expectIsPatch: true,
          checkHasBody: true);
 
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  Expect.isTrue(compiler.errors.isEmpty,
-                "Unexpected errors: ${compiler.errors}");
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  Expect.isTrue(collector.errors.isEmpty,
+                "Unexpected errors: ${collector.errors}");
 }
 
 Future testRegularMember() async {
   var compiler = await applyPatch(
       """
       class Class {
         void regular() {}
       }
       """,
       """
       @patch class Class {
       }
       """);
   var container = ensure(compiler, "Class", compiler.coreLibrary.find,
                          expectIsPatched: true);
   container.parseNode(compiler.parsing);
   ensure(compiler, "Class", compiler.coreLibrary.patch.find,
          expectIsPatch: true);
 
   ensure(compiler, "regular", container.lookupLocalMember,
          checkHasBody: true, expectIsRegular: true);
   ensure(compiler, "regular", container.patch.lookupLocalMember,
          checkHasBody: true, expectIsRegular: true);
 
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  Expect.isTrue(compiler.errors.isEmpty,
-                "Unexpected errors: ${compiler.errors}");
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  Expect.isTrue(collector.errors.isEmpty,
+                "Unexpected errors: ${collector.errors}");
 }
 
 Future testInjectedMember() async {
   var compiler = await applyPatch(
       """
       class Class {
       }
       """,
       """
       @patch class Class {
         void _injected() {}
       }
       """);
   var container = ensure(compiler, "Class", compiler.coreLibrary.find,
                          expectIsPatched: true);
   container.parseNode(compiler.parsing);
   ensure(compiler, "Class", compiler.coreLibrary.patch.find,
          expectIsPatch: true);
 
   ensure(compiler, "_injected", container.lookupLocalMember,
          expectIsFound: false);
   ensure(compiler, "_injected", container.patch.lookupLocalMember,
          checkHasBody: true, expectIsRegular: true);
 
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  Expect.isTrue(compiler.errors.isEmpty,
-                "Unexpected errors: ${compiler.errors}");
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  Expect.isTrue(collector.errors.isEmpty,
+                "Unexpected errors: ${collector.errors}");
 }
 
 Future testInjectedPublicMember() async {
   var compiler = await applyPatch(
       """
       class Class {
       }
       """,
       """
       @patch class Class {
         void injected() {}
       }
       """);
   var container = ensure(compiler, "Class", compiler.coreLibrary.find,
                          expectIsPatched: true);
   container.parseNode(compiler.parsing);
   ensure(compiler, "Class", compiler.coreLibrary.patch.find,
          expectIsPatch: true);
 
   ensure(compiler, "injected", container.lookupLocalMember,
          expectIsFound: false);
   ensure(compiler, "injected", container.patch.lookupLocalMember,
          checkHasBody: true, expectIsRegular: true);
 
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  Expect.equals(1, compiler.errors.length,
-                "Unexpected errors: ${compiler.errors}");
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  Expect.equals(1, collector.errors.length,
+                "Unexpected errors: ${collector.errors}");
   Expect.isTrue(
-      compiler.errors[0].message.kind == MessageKind.INJECTED_PUBLIC_MEMBER);
+      collector.errors.first.message.kind ==
+          MessageKind.INJECTED_PUBLIC_MEMBER);
 }
 
 Future testInjectedFunction() async {
   var compiler = await applyPatch(
       "",
       "int _function() => 5;");
   ensure(compiler,
          "_function",
          compiler.coreLibrary.find,
          expectIsFound: false);
   ensure(compiler,
          "_function",
          compiler.coreLibrary.patch.find,
          checkHasBody: true, expectIsRegular: true);
 
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  Expect.isTrue(compiler.errors.isEmpty,
-                "Unexpected errors: ${compiler.errors}");
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  Expect.isTrue(collector.errors.isEmpty,
+                "Unexpected errors: ${collector.errors}");
 }
 
 Future testInjectedPublicFunction() async {
   var compiler = await applyPatch(
       "",
       "int function() => 5;");
   ensure(compiler,
          "function",
          compiler.coreLibrary.find,
          expectIsFound: false);
   ensure(compiler,
          "function",
          compiler.coreLibrary.patch.find,
          checkHasBody: true, expectIsRegular: true);
 
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  Expect.equals(1, compiler.errors.length,
-                "Unexpected errors: ${compiler.errors}");
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  Expect.equals(1, collector.errors.length,
+                "Unexpected errors: ${collector.errors}");
   Expect.isTrue(
-      compiler.errors[0].message.kind == MessageKind.INJECTED_PUBLIC_MEMBER);
+      collector.errors.first.message.kind ==
+          MessageKind.INJECTED_PUBLIC_MEMBER);
 }
 
 Future testPatchSignatureCheck() async {
   var compiler = await applyPatch(
       """
       class Class {
         external String method1();
         external void method2(String str);
         external void method3(String s1);
         external void method4([String str]);
@@ skipping 18 matching lines @@
         @patch void method8({String s2}) {}
         @patch void method9(int str) {}
         @patch void method10([int str]) {}
         @patch void method11({int str}) {}
       }
       """);
   var container = ensure(compiler, "Class", compiler.coreLibrary.find,
                          expectIsPatched: true);
   container.ensureResolved(compiler.resolution);
   container.parseNode(compiler.parsing);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
 
   void expect(String methodName, List infos, List errors) {
-    compiler.clearMessages();
+    collector.clear();
     compiler.resolver.resolveMethodElement(
         ensure(compiler, methodName, container.lookupLocalMember,
             expectIsPatched: true, checkHasBody: true));
-    Expect.equals(0, compiler.warnings.length);
-    Expect.equals(infos.length, compiler.infos.length,
-                  "Unexpected infos: ${compiler.infos} on $methodName");
+    Expect.equals(0, collector.warnings.length);
+    Expect.equals(infos.length, collector.infos.length,
+                  "Unexpected infos: ${collector.infos} on $methodName");
     for (int i = 0 ; i < infos.length ; i++) {
-      Expect.equals(infos[i], compiler.infos[i].message.kind);
+      Expect.equals(infos[i], collector.infos.elementAt(i).message.kind);
     }
-    Expect.equals(errors.length, compiler.errors.length,
-                  "Unexpected errors: ${compiler.errors} on $methodName");
+    Expect.equals(errors.length, collector.errors.length,
+                  "Unexpected errors: ${collector.errors} on $methodName");
     for (int i = 0 ; i < errors.length ; i++) {
-      Expect.equals(errors[i], compiler.errors[i].message.kind);
+      Expect.equals(errors[i], collector.errors.elementAt(i).message.kind);
     }
   }
 
   expect("method1", [], [MessageKind.PATCH_RETURN_TYPE_MISMATCH]);
   expect("method2", [],
          [MessageKind.PATCH_REQUIRED_PARAMETER_COUNT_MISMATCH]);
   expect("method3", [MessageKind.PATCH_POINT_TO_PARAMETER],
                     [MessageKind.PATCH_PARAMETER_MISMATCH]);
   expect("method4", [],
          [MessageKind.PATCH_OPTIONAL_PARAMETER_COUNT_MISMATCH]);
@@ skipping 16 matching lines @@
 Future testExternalWithoutImplementationTopLevel() async {
   var compiler = await applyPatch(
       """
       external void foo();
       """,
       """
       // @patch void foo() {}
       """);
   var function = ensure(compiler, "foo", compiler.coreLibrary.find);
   compiler.resolver.resolve(function);
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  print('testExternalWithoutImplementationTopLevel:${compiler.errors}');
-  Expect.equals(1, compiler.errors.length);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  print('testExternalWithoutImplementationTopLevel:${collector.errors}');
+  Expect.equals(1, collector.errors.length);
   Expect.isTrue(
-      compiler.errors[0].message.kind ==
+      collector.errors.first.message.kind ==
           MessageKind.PATCH_EXTERNAL_WITHOUT_IMPLEMENTATION);
   Expect.stringEquals('External method without an implementation.',
-                      compiler.errors[0].message.toString());
+                      collector.errors.first.message.toString());
 }
 
 Future testExternalWithoutImplementationMember() async {
   var compiler = await applyPatch(
       """
       class Class {
         external void foo();
       }
       """,
       """
       @patch class Class {
         // @patch void foo() {}
       }
       """);
   var container = ensure(compiler, "Class", compiler.coreLibrary.find,
                          expectIsPatched: true);
   container.parseNode(compiler.parsing);
-
-  compiler.warnings.clear();
-  compiler.errors.clear();
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  collector.clear();
   compiler.resolver.resolveMethodElement(
       ensure(compiler, "foo", container.lookupLocalMember));
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  print('testExternalWithoutImplementationMember:${compiler.errors}');
-  Expect.equals(1, compiler.errors.length);
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  print('testExternalWithoutImplementationMember:${collector.errors}');
+  Expect.equals(1, collector.errors.length);
   Expect.isTrue(
-      compiler.errors[0].message.kind ==
+      collector.errors.first.message.kind ==
           MessageKind.PATCH_EXTERNAL_WITHOUT_IMPLEMENTATION);
   Expect.stringEquals('External method without an implementation.',
-                      compiler.errors[0].message.toString());
+                      collector.errors.first.message.toString());
 }
 
 Future testIsSubclass() async {
   var compiler = await applyPatch(
       """
       class A {}
       """,
       """
       @patch class A {}
       """);
   ClassElement cls = ensure(compiler, "A", compiler.coreLibrary.find,
                             expectIsPatched: true);
   ClassElement patch = cls.patch;
   Expect.isTrue(cls != patch);
   Expect.isTrue(cls.isSubclassOf(patch));
   Expect.isTrue(patch.isSubclassOf(cls));
 }
 
 Future testPatchNonExistingTopLevel() async {
   var compiler = await applyPatch(
       """
       // class Class {}
       """,
       """
       @patch class Class {}
       """);
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  print('testPatchNonExistingTopLevel:${compiler.errors}');
-  Expect.equals(1, compiler.errors.length);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  print('testPatchNonExistingTopLevel:${collector.errors}');
+  Expect.equals(1, collector.errors.length);
   Expect.isTrue(
-      compiler.errors[0].message.kind == MessageKind.PATCH_NON_EXISTING);
+      collector.errors.first.message.kind == MessageKind.PATCH_NON_EXISTING);
 }
 
 Future testPatchNonExistingMember() async {
   var compiler = await applyPatch(
       """
       class Class {}
       """,
       """
       @patch class Class {
         @patch void foo() {}
       }
       """);
   var container = ensure(compiler, "Class", compiler.coreLibrary.find,
                          expectIsPatched: true);
   container.parseNode(compiler.parsing);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
 
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  print('testPatchNonExistingMember:${compiler.errors}');
-  Expect.equals(1, compiler.errors.length);
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  print('testPatchNonExistingMember:${collector.errors}');
+  Expect.equals(1, collector.errors.length);
   Expect.isTrue(
-      compiler.errors[0].message.kind == MessageKind.PATCH_NON_EXISTING);
+      collector.errors.first.message.kind == MessageKind.PATCH_NON_EXISTING);
 }
 
 Future testPatchNonPatchablePatch() async {
   var compiler = await applyPatch(
       """
       external get foo;
       """,
       """
       @patch var foo;
       """);
   ensure(compiler, "foo", compiler.coreLibrary.find);
 
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  print('testPatchNonPatchablePatch:${compiler.errors}');
-  Expect.equals(1, compiler.errors.length);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  print('testPatchNonPatchablePatch:${collector.errors}');
+  Expect.equals(1, collector.errors.length);
   Expect.isTrue(
-      compiler.errors[0].message.kind == MessageKind.PATCH_NONPATCHABLE);
+      collector.errors.first.message.kind == MessageKind.PATCH_NONPATCHABLE);
 }
 
 Future testPatchNonPatchableOrigin() async {
   var compiler = await applyPatch(
       """
       external var foo;
       """,
       """
       @patch get foo => 0;
       """);
   ensure(compiler, "foo", compiler.coreLibrary.find);
 
-  Expect.isTrue(compiler.warnings.isEmpty,
-                "Unexpected warnings: ${compiler.warnings}");
-  print('testPatchNonPatchableOrigin:${compiler.errors}');
-  Expect.equals(2, compiler.errors.length);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  Expect.isTrue(collector.warnings.isEmpty,
+                "Unexpected warnings: ${collector.warnings}");
+  print('testPatchNonPatchableOrigin:${collector.errors}');
+  Expect.equals(2, collector.errors.length);
   Expect.equals(
-      MessageKind.EXTRANEOUS_MODIFIER, compiler.errors[0].message.kind);
+      MessageKind.EXTRANEOUS_MODIFIER, collector.errors.first.message.kind);
   Expect.equals(
       // TODO(ahe): Eventually, this error should be removed as it will be
       // handled by the regular parser.
-      MessageKind.PATCH_NONPATCHABLE, compiler.errors[1].message.kind);
+      MessageKind.PATCH_NONPATCHABLE,
+      collector.errors.elementAt(1).message.kind);
 }
 
 Future testPatchNonExternalTopLevel() async {
   var compiler = await applyPatch(
       """
       void foo() {}
       """,
       """
       @patch void foo() {}
       """);
-  print('testPatchNonExternalTopLevel.errors:${compiler.errors}');
-  print('testPatchNonExternalTopLevel.warnings:${compiler.warnings}');
-  Expect.equals(1, compiler.errors.length);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  print('testPatchNonExternalTopLevel.errors:${collector.errors}');
+  print('testPatchNonExternalTopLevel.warnings:${collector.warnings}');
+  Expect.equals(1, collector.errors.length);
   Expect.isTrue(
-      compiler.errors[0].message.kind == MessageKind.PATCH_NON_EXTERNAL);
-  Expect.equals(0, compiler.warnings.length);
-  Expect.equals(1, compiler.infos.length);
-  Expect.isTrue(compiler.infos[0].message.kind ==
+      collector.errors.first.message.kind == MessageKind.PATCH_NON_EXTERNAL);
+  Expect.equals(0, collector.warnings.length);
+  Expect.equals(1, collector.infos.length);
+  Expect.isTrue(collector.infos.first.message.kind ==
       MessageKind.PATCH_POINT_TO_FUNCTION);
 }
 
 Future testPatchNonExternalMember() async {
   var compiler = await applyPatch(
       """
       class Class {
         void foo() {}
       }
       """,
       """
       @patch class Class {
         @patch void foo() {}
       }
       """);
   var container = ensure(compiler, "Class", compiler.coreLibrary.find,
                          expectIsPatched: true);
   container.parseNode(compiler.parsing);
 
-  print('testPatchNonExternalMember.errors:${compiler.errors}');
-  print('testPatchNonExternalMember.warnings:${compiler.warnings}');
-  Expect.equals(1, compiler.errors.length);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  print('testPatchNonExternalMember.errors:${collector.errors}');
+  print('testPatchNonExternalMember.warnings:${collector.warnings}');
+  Expect.equals(1, collector.errors.length);
   Expect.isTrue(
-      compiler.errors[0].message.kind == MessageKind.PATCH_NON_EXTERNAL);
-  Expect.equals(0, compiler.warnings.length);
-  Expect.equals(1, compiler.infos.length);
-  Expect.isTrue(compiler.infos[0].message.kind ==
+      collector.errors.first.message.kind == MessageKind.PATCH_NON_EXTERNAL);
+  Expect.equals(0, collector.warnings.length);
+  Expect.equals(1, collector.infos.length);
+  Expect.isTrue(collector.infos.first.message.kind ==
       MessageKind.PATCH_POINT_TO_FUNCTION);
 }
 
 Future testPatchNonClass() async {
   var compiler = await applyPatch(
       """
       external void Class() {}
       """,
       """
       @patch class Class {}
       """);
-  print('testPatchNonClass.errors:${compiler.errors}');
-  print('testPatchNonClass.warnings:${compiler.warnings}');
-  Expect.equals(1, compiler.errors.length);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  print('testPatchNonClass.errors:${collector.errors}');
+  print('testPatchNonClass.warnings:${collector.warnings}');
+  Expect.equals(1, collector.errors.length);
   Expect.isTrue(
-      compiler.errors[0].message.kind == MessageKind.PATCH_NON_CLASS);
-  Expect.equals(0, compiler.warnings.length);
-  Expect.equals(1, compiler.infos.length);
+      collector.errors.first.message.kind == MessageKind.PATCH_NON_CLASS);
+  Expect.equals(0, collector.warnings.length);
+  Expect.equals(1, collector.infos.length);
   Expect.isTrue(
-      compiler.infos[0].message.kind == MessageKind.PATCH_POINT_TO_CLASS);
+      collector.infos.first.message.kind == MessageKind.PATCH_POINT_TO_CLASS);
 }
 
 Future testPatchNonGetter() async {
   var compiler = await applyPatch(
       """
       external void foo() {}
       """,
       """
       @patch get foo => 0;
       """);
-  print('testPatchNonClass.errors:${compiler.errors}');
-  print('testPatchNonClass.warnings:${compiler.warnings}');
-  Expect.equals(1, compiler.errors.length);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  print('testPatchNonClass.errors:${collector.errors}');
+  print('testPatchNonClass.warnings:${collector.warnings}');
+  Expect.equals(1, collector.errors.length);
   Expect.isTrue(
-      compiler.errors[0].message.kind == MessageKind.PATCH_NON_GETTER);
-  Expect.equals(0, compiler.warnings.length);
-  Expect.equals(1, compiler.infos.length);
+      collector.errors.first.message.kind == MessageKind.PATCH_NON_GETTER);
+  Expect.equals(0, collector.warnings.length);
+  Expect.equals(1, collector.infos.length);
   Expect.isTrue(
-      compiler.infos[0].message.kind == MessageKind.PATCH_POINT_TO_GETTER);
+      collector.infos.first.message.kind == MessageKind.PATCH_POINT_TO_GETTER);
 }
 
 Future testPatchNoGetter() async {
   var compiler = await applyPatch(
       """
       external set foo(var value) {}
       """,
       """
       @patch get foo => 0;
       """);
-  print('testPatchNonClass.errors:${compiler.errors}');
-  print('testPatchNonClass.warnings:${compiler.warnings}');
-  Expect.equals(1, compiler.errors.length);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  print('testPatchNonClass.errors:${collector.errors}');
+  print('testPatchNonClass.warnings:${collector.warnings}');
+  Expect.equals(1, collector.errors.length);
   Expect.isTrue(
-      compiler.errors[0].message.kind == MessageKind.PATCH_NO_GETTER);
-  Expect.equals(0, compiler.warnings.length);
-  Expect.equals(1, compiler.infos.length);
+      collector.errors.first.message.kind == MessageKind.PATCH_NO_GETTER);
+  Expect.equals(0, collector.warnings.length);
+  Expect.equals(1, collector.infos.length);
   Expect.isTrue(
-      compiler.infos[0].message.kind == MessageKind.PATCH_POINT_TO_GETTER);
+      collector.infos.first.message.kind == MessageKind.PATCH_POINT_TO_GETTER);
 }
 
 Future testPatchNonSetter() async {
   var compiler = await applyPatch(
       """
       external void foo() {}
       """,
       """
       @patch set foo(var value) {}
       """);
-  print('testPatchNonClass.errors:${compiler.errors}');
-  print('testPatchNonClass.warnings:${compiler.warnings}');
-  Expect.equals(1, compiler.errors.length);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  print('testPatchNonClass.errors:${collector.errors}');
+  print('testPatchNonClass.warnings:${collector.warnings}');
+  Expect.equals(1, collector.errors.length);
   Expect.isTrue(
-      compiler.errors[0].message.kind == MessageKind.PATCH_NON_SETTER);
-  Expect.equals(0, compiler.warnings.length);
-  Expect.equals(1, compiler.infos.length);
+      collector.errors.first.message.kind == MessageKind.PATCH_NON_SETTER);
+  Expect.equals(0, collector.warnings.length);
+  Expect.equals(1, collector.infos.length);
   Expect.isTrue(
-      compiler.infos[0].message.kind == MessageKind.PATCH_POINT_TO_SETTER);
+      collector.infos.first.message.kind == MessageKind.PATCH_POINT_TO_SETTER);
 }
 
 Future testPatchNoSetter() async {
   var compiler = await applyPatch(
       """
       external get foo;
       """,
       """
       @patch set foo(var value) {}
       """);
-  print('testPatchNonClass.errors:${compiler.errors}');
-  print('testPatchNonClass.warnings:${compiler.warnings}');
-  Expect.equals(1, compiler.errors.length);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  print('testPatchNonClass.errors:${collector.errors}');
+  print('testPatchNonClass.warnings:${collector.warnings}');
+  Expect.equals(1, collector.errors.length);
   Expect.isTrue(
-      compiler.errors[0].message.kind == MessageKind.PATCH_NO_SETTER);
-  Expect.equals(0, compiler.warnings.length);
-  Expect.equals(1, compiler.infos.length);
+      collector.errors.first.message.kind == MessageKind.PATCH_NO_SETTER);
+  Expect.equals(0, collector.warnings.length);
+  Expect.equals(1, collector.infos.length);
   Expect.isTrue(
-      compiler.infos[0].message.kind == MessageKind.PATCH_POINT_TO_SETTER);
+      collector.infos.first.message.kind == MessageKind.PATCH_POINT_TO_SETTER);
 }
 
 Future testPatchNonFunction() async {
   var compiler = await applyPatch(
       """
       external get foo;
       """,
       """
       @patch void foo() {}
       """);
-  print('testPatchNonClass.errors:${compiler.errors}');
-  print('testPatchNonClass.warnings:${compiler.warnings}');
-  Expect.equals(1, compiler.errors.length);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
+  print('testPatchNonClass.errors:${collector.errors}');
+  print('testPatchNonClass.warnings:${collector.warnings}');
+  Expect.equals(1, collector.errors.length);
   Expect.isTrue(
-      compiler.errors[0].message.kind == MessageKind.PATCH_NON_FUNCTION);
-  Expect.equals(0, compiler.warnings.length);
-  Expect.equals(1, compiler.infos.length);
+      collector.errors.first.message.kind == MessageKind.PATCH_NON_FUNCTION);
+  Expect.equals(0, collector.warnings.length);
+  Expect.equals(1, collector.infos.length);
   Expect.isTrue(
-      compiler.infos[0].message.kind ==
+      collector.infos.first.message.kind ==
           MessageKind.PATCH_POINT_TO_FUNCTION);
 }
 
 Future testPatchAndSelector() async {
   var compiler = await applyPatch(
       """
       class A {
         external void clear();
       }
       class B extends A {
@@ skipping 60 matching lines @@
   Future expect(String patchText, [expectedWarnings]) async {
     if (expectedWarnings == null) expectedWarnings = [];
     if (expectedWarnings is! List) {
       expectedWarnings = <MessageKind>[expectedWarnings];
     }
 
     var compiler = await applyPatch('', patchText, analyzeAll: true,
                analyzeOnly: true);
       compiler.librariesToAnalyzeWhenRun = [Uri.parse('dart:core')];
     await compiler.run(null);
-    compareWarningKinds(patchText, expectedWarnings, compiler.warnings);
+    DiagnosticCollector collector = compiler.diagnosticCollector;
+    compareWarningKinds(patchText, expectedWarnings, collector.warnings);
   }
 
   await expect('String s = 0;', MessageKind.NOT_ASSIGNABLE);
   await expect('void method() { String s = 0; }', MessageKind.NOT_ASSIGNABLE);
   await expect('''
          class Class {
            String s = 0;
          }
          ''',
          MessageKind.NOT_ASSIGNABLE);
@@ skipping 51 matching lines @@
   String originText = "external void method();";
   String patchText = """
                      @patch void method() {
                        String s = 0;
                      }
                      """;
   var compiler = await applyPatch(originText, patchText,
              analyzeAll: true, analyzeOnly: true);
   compiler.librariesToAnalyzeWhenRun = [Uri.parse('dart:core')];
   await compiler.run(null);
+  DiagnosticCollector collector = compiler.diagnosticCollector;
   compareWarningKinds(patchText,
-      [MessageKind.NOT_ASSIGNABLE], compiler.warnings);
+      [MessageKind.NOT_ASSIGNABLE], collector.warnings);
 }
 
 main() {
   asyncTest(() async {
     await testPatchConstructor();
     await testPatchRedirectingConstructor();
     await testPatchFunction();
     await testPatchFunctionMetadata();
     await testPatchMember();
     await testPatchGetter();
@@ skipping 25 matching lines @@
     await testPatchNonFunction();
 
     await testPatchAndSelector();
 
     await testEffectiveTarget();
 
     await testAnalyzeAllInjectedMembers();
     await testTypecheckPatchedMembers();
   });
 }