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..607401ec002dcfebe857d95aebc908383567524f 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, ResolverErrorCode.PART_OF_UNNAMED_LIBRARY);
     } else {
       expect(errors, hasLength(1));
       expect(errors[0].errorCode,