fix(51820): disallow using readonly and declare with auto-accessor (#51824)

Author: a-tarasyuk

src/compiler/checker.ts

@@ -45580,6 +45580,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                         // If node.kind === SyntaxKind.Parameter, checkParameter reports an error if it's not a parameter property.
                         return grammarErrorOnNode(modifier, Diagnostics.readonly_modifier_can_only_appear_on_a_property_declaration_or_index_signature);
                     }
+                    else if (flags & ModifierFlags.Accessor) {
+                        return grammarErrorOnNode(modifier, Diagnostics._0_modifier_cannot_be_used_with_1_modifier, "readonly", "accessor");
+                    }
                     flags |= ModifierFlags.Readonly;
                     break;
 
@@ -45637,6 +45640,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                     else if (isPrivateIdentifierClassElementDeclaration(node)) {
                         return grammarErrorOnNode(modifier, Diagnostics._0_modifier_cannot_be_used_with_a_private_identifier, "declare");
                     }
+                    else if (flags & ModifierFlags.Accessor) {
+                        return grammarErrorOnNode(modifier, Diagnostics._0_modifier_cannot_be_used_with_1_modifier, "declare", "accessor");
+                    }
                     flags |= ModifierFlags.Ambient;
                     lastDeclare = modifier;
                     break;

tests/baselines/reference/autoAccessorDisallowedModifiers.errors.txt

@@ -11,24 +11,26 @@ tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowe
 tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(12,5): error TS1275: 'accessor' modifier can only appear on a property declaration.
 tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(13,5): error TS1275: 'accessor' modifier can only appear on a property declaration.
 tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(14,15): error TS1276: An 'accessor' property cannot be declared optional.
-tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(18,14): error TS1029: 'override' modifier must precede 'accessor' modifier.
-tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(22,5): error TS1070: 'accessor' modifier cannot appear on a type member.
-tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(25,1): error TS1275: 'accessor' modifier can only appear on a property declaration.
-tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(26,1): error TS1275: 'accessor' modifier can only appear on a property declaration.
+tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(15,14): error TS1243: 'readonly' modifier cannot be used with 'accessor' modifier.
+tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(16,14): error TS1243: 'declare' modifier cannot be used with 'accessor' modifier.
+tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(20,14): error TS1029: 'override' modifier must precede 'accessor' modifier.
+tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(24,5): error TS1070: 'accessor' modifier cannot appear on a type member.
 tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(27,1): error TS1275: 'accessor' modifier can only appear on a property declaration.
 tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(28,1): error TS1275: 'accessor' modifier can only appear on a property declaration.
 tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(29,1): error TS1275: 'accessor' modifier can only appear on a property declaration.
 tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(30,1): error TS1275: 'accessor' modifier can only appear on a property declaration.
 tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(31,1): error TS1275: 'accessor' modifier can only appear on a property declaration.
 tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(32,1): error TS1275: 'accessor' modifier can only appear on a property declaration.
 tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(33,1): error TS1275: 'accessor' modifier can only appear on a property declaration.
-tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(33,25): error TS2792: Cannot find module 'x'. Did you mean to set the 'moduleResolution' option to 'nodenext', or to add aliases to the 'paths' option?
 tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(34,1): error TS1275: 'accessor' modifier can only appear on a property declaration.
 tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(35,1): error TS1275: 'accessor' modifier can only appear on a property declaration.
+tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(35,25): error TS2792: Cannot find module 'x'. Did you mean to set the 'moduleResolution' option to 'nodenext', or to add aliases to the 'paths' option?
 tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(36,1): error TS1275: 'accessor' modifier can only appear on a property declaration.
+tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(37,1): error TS1275: 'accessor' modifier can only appear on a property declaration.
+tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts(38,1): error TS1275: 'accessor' modifier can only appear on a property declaration.
 
 
-==== tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts (28 errors) ====
+==== tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts (30 errors) ====
     abstract class C1 {
         accessor accessor a: any;
                  ~~~~~~~~
@@ -69,6 +71,12 @@ tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowe
         accessor l?: any;
                   ~
 !!! error TS1276: An 'accessor' property cannot be declared optional.
+        accessor readonly m: any;
+                 ~~~~~~~~
+!!! error TS1243: 'readonly' modifier cannot be used with 'accessor' modifier.
+        accessor declare n: any;
+                 ~~~~~~~
+!!! error TS1243: 'declare' modifier cannot be used with 'accessor' modifier.
     }
 
     class C2 extends C1 {

tests/baselines/reference/autoAccessorDisallowedModifiers.js

@@ -13,6 +13,8 @@ abstract class C1 {
     accessor set k(v: any) {}
     accessor constructor() {}
     accessor l?: any;
+    accessor readonly m: any;
+    accessor declare n: any;
 }
 
 class C2 extends C1 {
@@ -50,6 +52,7 @@ class C1 {
     accessor set k(v) { }
     constructor() { }
     accessor l;
+    accessor m;
 }
 class C2 extends C1 {
     accessor g;

tests/cases/conformance/classes/propertyMemberDeclarations/autoAccessorDisallowedModifiers.ts

@@ -15,6 +15,8 @@ abstract class C1 {
     accessor set k(v: any) {}
     accessor constructor() {}
     accessor l?: any;
+    accessor readonly m: any;
+    accessor declare n: any;
 }
 
 class C2 extends C1 {