Fine. Fix for requirements on instance/interface elements with missing names.

Change-Id: Ide320ccc1bd146aba60a0d2bced405fc2612a027
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/430880
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

Author: scheglov

pkg/analyzer/lib/src/fine/requirements.dart

@@ -882,8 +882,10 @@ class RequirementsManifest {
       return null;
     }
 
-    // SAFETY: we don't export elements without name.
-    var instanceName = element.lookupName!.asLookupName;
+    var instanceName = element.lookupName?.asLookupName;
+    if (instanceName == null) {
+      return null;
+    }
 
     var instancesMap = instances[libraryElement.uri] ??= {};
     var instanceItem =
@@ -916,8 +918,10 @@ class RequirementsManifest {
       return null;
     }
 
-    // SAFETY: we don't export elements without name.
-    var interfaceName = element.lookupName!.asLookupName;
+    var interfaceName = element.lookupName?.asLookupName;
+    if (interfaceName == null) {
+      return null;
+    }
 
     var interfacesMap = interfaces[libraryElement.uri] ??= {};
     var interfaceItem =

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

@@ -44373,6 +44373,64 @@ int get b => 0;
     );
   }
 
+  test_req_classElement_noName() async {
+    newFile(testFile.path, r'''
+class {}
+''');
+
+    _ManualRequirements.install((state) {
+      var e = state.singleUnit.libraryElement.classes.single;
+      e.getNamedConstructor2('foo');
+    });
+
+    await _runManualRequirementsRecording(
+      expectedEvents: r'''
+[status] working
+[operation] linkLibraryCycle SDK
+[operation] linkLibraryCycle
+  package:test/test.dart
+  requirements
+[operation] analyzedLibrary
+  file: /home/test/lib/test.dart
+  requirements
+[status] idle
+''',
+    );
+  }
+
+  test_req_extensionElement_noName() async {
+    newFile(testFile.path, r'''
+extension on int {
+  void foo() {}
+}
+''');
+
+    _ManualRequirements.install((state) {
+      var e = state.singleUnit.libraryElement.extensions.single;
+      e.getMethod('foo');
+    });
+
+    await _runManualRequirementsRecording(
+      expectedEvents: r'''
+[status] working
+[operation] linkLibraryCycle SDK
+[operation] linkLibraryCycle
+  package:test/test.dart
+  requirements
+    topLevels
+      dart:core
+        int: #M0
+[operation] analyzedLibrary
+  file: /home/test/lib/test.dart
+  requirements
+    topLevels
+      dart:core
+        int: #M0
+[status] idle
+''',
+    );
+  }
+
   test_req_instanceElement_getField() async {
     newFile('$testPackageLibPath/a.dart', r'''
 class A {
@@ -45197,6 +45255,10 @@ class _ManualRequirementsUnit {
 
   _ManualRequirementsUnit(this.unit);
 
+  LibraryElementImpl get libraryElement {
+    return libraryFragment.element;
+  }
+
   LibraryFragmentImpl get libraryFragment {
     return unit.declaredFragment!;
   }