Issue 43200. Report ASSIGNMENT_TO_FINAL when 'final late' has an initializer.

Bug: #43200
Change-Id: Ib79b4e8246f8f67661212c3d107de961d72132b4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/161471
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

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

@@ -265,9 +265,9 @@ class AssignmentExpressionResolver {
           CompileTimeErrorCode.ASSIGNMENT_TO_CONST,
           left,
         );
-      } else if (variable.isFinal && !variable.isLate) {
+      } else if (variable.setter == null) {
         if (variable is FieldElement) {
-          if (variable.setter == null && variable.isSynthetic) {
+          if (variable.isSynthetic) {
             _errorReporter.reportErrorForNode(
               CompileTimeErrorCode.ASSIGNMENT_TO_FINAL_NO_SETTER,
               left,

pkg/analyzer/lib/src/generated/error_verifier.dart

@@ -1647,38 +1647,52 @@ class ErrorVerifier extends RecursiveAstVisitor<void> {
       highlightedNode = expression.propertyName;
     }
     // check if element is assignable
-    Element toVariable(Element element) {
-      return element is PropertyAccessorElement ? element.variable : element;
-    }
-
-    element = toVariable(element);
     if (element is VariableElement) {
       if (element.isConst) {
         _errorReporter.reportErrorForNode(
-            CompileTimeErrorCode.ASSIGNMENT_TO_CONST, expression);
-      } else if (element.isFinal && !element.isLate) {
-        if (element is FieldElementImpl) {
-          if (element.setter == null && element.isSynthetic) {
+          CompileTimeErrorCode.ASSIGNMENT_TO_CONST,
+          expression,
+        );
+      } else if (element.isFinal) {
+        if (_isNonNullableByDefault) {
+          // Handled during resolution, with flow analysis.
+        } else {
+          _errorReporter.reportErrorForNode(
+            CompileTimeErrorCode.ASSIGNMENT_TO_FINAL_LOCAL,
+            expression,
+            [element.name],
+          );
+        }
+      }
+    } else if (element is PropertyAccessorElement && element.isGetter) {
+      var variable = element.variable;
+      if (variable.isConst) {
+        _errorReporter.reportErrorForNode(
+          CompileTimeErrorCode.ASSIGNMENT_TO_CONST,
+          expression,
+        );
+      } else if (variable.setter == null) {
+        if (variable is FieldElement) {
+          if (variable.isSynthetic) {
             _errorReporter.reportErrorForNode(
-                CompileTimeErrorCode.ASSIGNMENT_TO_FINAL_NO_SETTER,
-                highlightedNode,
-                [element.name, element.enclosingElement.displayName]);
+              CompileTimeErrorCode.ASSIGNMENT_TO_FINAL_NO_SETTER,
+              highlightedNode,
+              [variable.name, variable.enclosingElement.displayName],
+            );
           } else {
             _errorReporter.reportErrorForNode(
-                CompileTimeErrorCode.ASSIGNMENT_TO_FINAL,
-                highlightedNode,
-                [element.name]);
+              CompileTimeErrorCode.ASSIGNMENT_TO_FINAL,
+              highlightedNode,
+              [variable.name],
+            );
           }
           return;
         }
-        if (_isNonNullableByDefault && element is PromotableElement) {
-          // Handled during resolution, with flow analysis.
-        } else {
-          _errorReporter.reportErrorForNode(
-              CompileTimeErrorCode.ASSIGNMENT_TO_FINAL_LOCAL,
-              highlightedNode,
-              [element.name]);
-        }
+        _errorReporter.reportErrorForNode(
+          CompileTimeErrorCode.ASSIGNMENT_TO_FINAL_LOCAL,
+          highlightedNode,
+          [variable.name],
+        );
       }
     } else if (element is FunctionElement) {
       _errorReporter.reportErrorForNode(

pkg/analyzer/test/src/diagnostics/assignment_to_final_local_test.dart

@@ -160,13 +160,15 @@ void f(int value) {
   }
 
   test_topLevelVariable_late() async {
-    await assertNoErrorsInCode('''
+    await assertErrorsInCode('''
 late final int a;
 late final int b = 0;
 void f() {
   a = 1;
   b = 1;
 }
-''');
+''', [
+      error(CompileTimeErrorCode.ASSIGNMENT_TO_FINAL_LOCAL, 62, 1),
+    ]);
   }
 }

pkg/analyzer/test/src/diagnostics/assignment_to_final_test.dart

@@ -46,8 +46,23 @@ f() {
 @reflectiveTest
 class AssignmentToFinalWithNullSafetyTest extends AssignmentToFinalTest
     with WithNullSafetyMixin {
-  test_field_late() async {
-    await assertNoErrorsInCode('''
+  test_field_late_propertyAccess() async {
+    await assertErrorsInCode('''
+class A {
+  late final int a;
+  late final int b = 0;
+  void m() {
+    this.a = 1;
+    this.b = 1;
+  }
+}
+''', [
+      error(CompileTimeErrorCode.ASSIGNMENT_TO_FINAL, 92, 1),
+    ]);
+  }
+
+  test_field_late_simpleIdentifier() async {
+    await assertErrorsInCode('''
 class A {
   late final int a;
   late final int b = 0;
@@ -56,11 +71,29 @@ class A {
     b = 1;
   }
 }
-''');
+''', [
+      error(CompileTimeErrorCode.ASSIGNMENT_TO_FINAL, 82, 1),
+    ]);
   }
 
-  test_field_static_late() async {
-    await assertNoErrorsInCode('''
+  test_field_static_final_late_prefixedIdentifier() async {
+    await assertErrorsInCode('''
+class A {
+  static late final int a;
+  static late final int b = 0;
+}
+
+void f() {
+  A.a = 1;
+  A.b = 1;
+}
+''', [
+      error(CompileTimeErrorCode.ASSIGNMENT_TO_FINAL, 97, 1),
+    ]);
+  }
+
+  test_field_static_final_late_simpleIdentifier() async {
+    await assertErrorsInCode('''
 class A {
   static late final int a;
   static late final int b = 0;
@@ -69,7 +102,9 @@ class A {
     b = 1;
   }
 }
-''');
+''', [
+      error(CompileTimeErrorCode.ASSIGNMENT_TO_FINAL, 96, 1),
+    ]);
   }
 
   test_set_abstract_field_final_invalid() async {

tests/language/extension_methods/static_extension_getter_setter_conflicts_test.dart

@@ -109,7 +109,7 @@ void test1() {
 
   c1a.m1 = 0;
   //  ^^
-  // [analyzer] COMPILE_TIME_ERROR.ASSIGNMENT_TO_FINAL_LOCAL
+  // [analyzer] COMPILE_TIME_ERROR.ASSIGNMENT_TO_FINAL_NO_SETTER
   // [cfe] The setter 'm1' isn't defined for the class 'C1<int>'.
 
   c1a.m2;
@@ -195,7 +195,7 @@ void test1() {
 
   c1c.m1 = 0;
   //  ^^
-  // [analyzer] COMPILE_TIME_ERROR.ASSIGNMENT_TO_FINAL_LOCAL
+  // [analyzer] COMPILE_TIME_ERROR.ASSIGNMENT_TO_FINAL_NO_SETTER
   // [cfe] The setter 'm1' isn't defined for the class 'C1<Object>'.
 
   c1c.m2;

tests/language_2/extension_methods/static_extension_getter_setter_conflicts_test.dart

@@ -109,7 +109,7 @@ void test1() {
 
   c1a.m1 = 0;
   //  ^^
-  // [analyzer] COMPILE_TIME_ERROR.ASSIGNMENT_TO_FINAL_LOCAL
+  // [analyzer] COMPILE_TIME_ERROR.ASSIGNMENT_TO_FINAL_NO_SETTER
   // [cfe] The setter 'm1' isn't defined for the class 'C1<int>'.
 
   c1a.m2;