Issue 4641. Resolve 'part of' to LibraryElement

editor/tools/plugins/com.google.dart.tools.core_test/src/com/google/dart/tools/core/utilities/ast/DartElementLocatorTest.java

Index: editor/tools/plugins/com.google.dart.tools.core_test/src/com/google/dart/tools/core/utilities/ast/DartElementLocatorTest.java
diff --git a/editor/tools/plugins/com.google.dart.tools.core_test/src/com/google/dart/tools/core/utilities/ast/DartElementLocatorTest.java b/editor/tools/plugins/com.google.dart.tools.core_test/src/com/google/dart/tools/core/utilities/ast/DartElementLocatorTest.java
index a838a55b8fba0c1585180b096a47a4a62d73ae35..c55b07dda8e78807771dd51e2a93b1d7f47bfbb8 100644
--- a/editor/tools/plugins/com.google.dart.tools.core_test/src/com/google/dart/tools/core/utilities/ast/DartElementLocatorTest.java
+++ b/editor/tools/plugins/com.google.dart.tools.core_test/src/com/google/dart/tools/core/utilities/ast/DartElementLocatorTest.java
@@ -13,6 +13,8 @@
  */
 package com.google.dart.tools.core.utilities.ast;
 
+import static org.fest.assertions.Assertions.assertThat;
+
 import com.google.common.base.Joiner;
 import com.google.common.collect.Lists;
 import com.google.dart.compiler.DartCompilationError;
@@ -34,8 +36,6 @@ import junit.framework.TestCase;
 
 import org.eclipse.core.resources.IResource;
 
-import static org.fest.assertions.Assertions.assertThat;
-
 import java.util.List;
 
 /**
@@ -404,6 +404,41 @@ public class DartElementLocatorTest extends TestCase {
         4);
   }
 
+  // XXX
+  public void test_LibraryUnit_onPartOf() throws Exception {
+    TestProject testProject = new TestProject("Test");
+    try {
+      IResource libResourceA = testProject.setUnitContent(
+          "Lib.dart",
+          Joiner.on("\n").join(
+              "// filler filler filler filler filler filler filler filler filler filler",
+              "library my.lib;",
+              "part 'Test.dart';",
+              "")).getResource();
+      testProject.setUnitContent(
+          "Test.dart",
+          Joiner.on("\n").join(
+              "// filler filler filler filler filler filler filler filler filler filler",
+              "part of my.lib;",
+              ""));
+      TestProject.waitForAutoBuild();
+      DartLibrary library = testProject.getDartProject().getDartLibrary(libResourceA);
+      CompilationUnit testUnit = library.getCompilationUnit("Test.dart");
+      // usage of "aaa" = "libraryA"
+      {
+        DartElement element = assertLocation(
+            testUnit,
+            "my.lib",
+            CompilationUnit.class,
+            "library my.lib);",
+            0);
+        assertSame(library.getDefiningCompilationUnit(), element);
+      }
+    } finally {
+      testProject.dispose();
+    }
+  }
+
   public void test_Method_call() throws Exception {
     testElementLocator(
         formatLines(