Test also search for CompilationUnitElement referenced in 'export' and 'part'.

Change-Id: I272de045d5e8d3287c568c108cf559955d32a091
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/388243
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
diff --git a/pkg/analyzer/test/src/dart/analysis/search_test.dart b/pkg/analyzer/test/src/dart/analysis/search_test.dart
index 6859bb6..ae81919 100644
--- a/pkg/analyzer/test/src/dart/analysis/search_test.dart
+++ b/pkg/analyzer/test/src/dart/analysis/search_test.dart
@@ -1029,17 +1029,46 @@
 ''');
   }
 
-  test_searchReferences_CompilationUnitElement() async {
+  test_searchReferences_CompilationUnitElement_export() async {
+    newFile('$testPackageLibPath/foo.dart', '');
+    await resolveTestCode('''
+export 'foo.dart';
+''');
+    var element = findElement
+        .export('package:test/foo.dart')
+        .exportedLibrary!
+        .definingCompilationUnit;
+    await assertElementReferencesText(element, r'''
+self
+  7 1:8 |'foo.dart'| REFERENCE qualified
+''');
+  }
+
+  test_searchReferences_CompilationUnitElement_import() async {
     newFile('$testPackageLibPath/foo.dart', '');
     await resolveTestCode('''
 import 'foo.dart';
-export 'foo.dart';
 ''');
     var element = findElement.importFind('package:test/foo.dart').unitElement;
     await assertElementReferencesText(element, r'''
 self
   7 1:8 |'foo.dart'| REFERENCE qualified
-  26 2:8 |'foo.dart'| REFERENCE qualified
+''');
+  }
+
+  test_searchReferences_CompilationUnitElement_part() async {
+    newFile('$testPackageLibPath/foo.dart', r'''
+part of 'test.dart';
+''');
+
+    await resolveTestCode('''
+part 'foo.dart';
+''');
+
+    var element = findElement.part('package:test/foo.dart');
+    await assertElementReferencesText(element, r'''
+self
+  5 1:6 |'foo.dart'| REFERENCE qualified
 ''');
   }