Report an error when a part-of refers to an unnamed library.

pkg/analyzer/test/src/dart/analysis/driver_test.dart

Index: pkg/analyzer/test/src/dart/analysis/driver_test.dart
diff --git a/pkg/analyzer/test/src/dart/analysis/driver_test.dart b/pkg/analyzer/test/src/dart/analysis/driver_test.dart
index 8985c013873e4675cfc84b166d86a00cc40a8f39..3e5f818d31dbd255c801ad69784f5a0634766012 100644
--- a/pkg/analyzer/test/src/dart/analysis/driver_test.dart
+++ b/pkg/analyzer/test/src/dart/analysis/driver_test.dart
@@ -503,8 +503,8 @@ part of lib;
     AnalysisResult libResult = await driver.getResult(lib);
     List<AnalysisError> errors = libResult.errors;
     if (libResult.unit.element.context.analysisOptions.enableUriInPartOf) {
-      // TODO(28522): Should cause an error for wrong library name.
-      expect(errors, hasLength(0));
+      expect(errors, hasLength(1));
+      expect(errors[0].errorCode, StaticWarningCode.PART_OF_UNNAMED_LIBRARY);
     } else {
       expect(errors, hasLength(1));
       expect(errors[0].errorCode,
@@ -558,6 +558,28 @@ part of 'other_lib.dart';
     expect(errors[0].errorCode, StaticWarningCode.PART_OF_DIFFERENT_LIBRARY);
   }
 
+  test_analyze_resolveDirectives_error_partOfUnnamedLibrary_byName() async {
+    var lib = _p('/test/lib.dart');
+    var part = _p('/test/part.dart');
+    provider.newFile(
+        lib,
+        '''
+part 'part.dart';
+''');
+    provider.newFile(
+        part,
+        '''
+part of lib1;
+''');
+
+    driver.addFile(lib);
+
+    AnalysisResult libResult = await driver.getResult(lib);
+    List<AnalysisError> errors = libResult.errors;
+    expect(errors, hasLength(1));
+    expect(errors[0].errorCode, StaticWarningCode.PART_OF_UNNAMED_LIBRARY);
+  }
+
   test_analyze_resolveDirectives_error_partOfNonPart() async {
     var lib = _p('/test/lib.dart');
     var part = _p('/test/part.dart');