Change BazelWorkspace so that it checks the main source directory before READONLY.

pkg/analyzer/test/generated/bazel_test.dart

 // Copyright (c) 2016, 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.
 
 library analyzer.test.generated.bazel_test;
 
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/generated/bazel.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:test/test.dart';
@@ skipping 594 matching lines @@
             .findFile(_p('/Users/user/test/prime/my/module/test3.dart'))
             .path,
         _p('/Users/user/test/prime/bazel-genfiles/my/module/test3.dart'));
     expect(
         workspace
             .findFile(_p('/Users/user/test/prime/other/module/test4.dart'))
             .path,
         _p('/Users/user/test/READONLY/prime/other/module/test4.dart'));
   }
 
+  void test_findFile_main_overrides_readonly() {
+    provider.newFolder(_p('/Users/user/test/READONLY/prime'));
+    provider.newFolder(_p('/Users/user/test/prime'));
+    provider.newFolder(_p('/Users/user/test/prime/bazel-genfiles'));
+    provider.newFile(_p('/Users/user/test/prime/my/module/test.dart'), '');
+    provider.newFile(
+        _p('/Users/user/test/READONLY/prime/my/module/test.dart'), '');
+    BazelWorkspace workspace =
+        BazelWorkspace.find(provider, _p('/Users/user/test/prime/my/module'));
+    expect(
+        workspace
+            .findFile(_p('/Users/user/test/prime/my/module/test.dart'))
+            .path,
+        _p('/Users/user/test/prime/my/module/test.dart'));
+  }
+
   void test_findFile_noReadOnly() {
     provider.newFile(_p('/workspace/WORKSPACE'), '');
     provider.newFile(_p('/workspace/my/module/test1.dart'), '');
     provider.newFile(_p('/workspace/my/module/test2.dart'), '');
     provider.newFile(_p('/workspace/my/module/test3.dart'), '');
     provider.newFile(_p('/workspace/bazel-bin/my/module/test2.dart'), '');
     provider.newFile(_p('/workspace/bazel-genfiles/my/module/test3.dart'), '');
     BazelWorkspace workspace =
         BazelWorkspace.find(provider, _p('/workspace/my/module'));
     expect(workspace.findFile(_p('/workspace/my/module/test1.dart')).path,
@@ skipping 11 matching lines @@
   /**
    * Return the [provider] specific path for the given Posix [path].
    */
   String _p(String path) => provider.convertPath(path);
 }
 
 class _MockSource extends TypedMock implements Source {
   final String fullName;
   _MockSource(this.fullName);
 }