Fix an issue with null access when resolving receiver type.

Bug: #61854
Change-Id: I279d164711160fbf123034deaeb5e09aac92cf57
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/457941
Reviewed-by: Konstantin Shcheglov <[email protected]>
Reviewed-by: Johnni Winther <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: fshcheglov

pkg/analyzer/lib/src/dart/resolver/method_invocation_resolver.dart

@@ -1156,7 +1156,11 @@ class MethodInvocationResolver with ScopeHelpers {
 
     String receiverClassName = '<unknown>';
     if (receiverType is InterfaceTypeImpl) {
-      receiverClassName = receiverType.element.name!;
+      if (receiverType.element.name case var name?) {
+        receiverClassName = name;
+      } else {
+        return null;
+      }
     } else if (receiverType is FunctionType) {
       receiverClassName = 'Function';
     }

pkg/analyzer/test/src/dart/resolution/method_invocation_test.dart

@@ -2590,6 +2590,38 @@ MethodInvocation
 ''');
   }
 
+  test_error_undefinedMethod_noTarget_synthetic_class() async {
+    await assertErrorsInCode(
+      r'''
+class {
+  void f() {
+    foo(0);
+  }
+}
+''',
+      [error(ParserErrorCode.missingIdentifier, 6, 1)],
+    );
+
+    var node = findNode.methodInvocation('foo(0);');
+    assertResolvedNodeText(node, r'''
+MethodInvocation
+  methodName: SimpleIdentifier
+    token: foo
+    element: <null>
+    staticType: InvalidType
+  argumentList: ArgumentList
+    leftParenthesis: (
+    arguments
+      IntegerLiteral
+        literal: 0
+        correspondingParameter: <null>
+        staticType: int
+    rightParenthesis: )
+  staticInvokeType: InvalidType
+  staticType: InvalidType
+''');
+  }
+
   test_error_undefinedMethod_null() async {
     await assertErrorsInCode(
       r'''