fix(55899): Indexing/element access on super avoids instance property checks

src/compiler/checker.ts

@@ -33621,7 +33621,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
      * @param prop The symbol for the property being accessed.
      */
     function checkPropertyAccessibility(
-        node: PropertyAccessExpression | QualifiedName | PropertyAccessExpression | VariableDeclaration | ParameterDeclaration | ImportTypeNode | PropertyAssignment | ShorthandPropertyAssignment | BindingElement,
+        node: PropertyAccessExpression | QualifiedName | ElementAccessExpression | VariableDeclaration | ParameterDeclaration | ImportTypeNode | PropertyAssignment | ShorthandPropertyAssignment | BindingElement,
         isSuper: boolean,
         writing: boolean,
         type: Type,
@@ -33631,7 +33631,8 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         const errorNode = !reportError ? undefined :
             node.kind === SyntaxKind.QualifiedName ? node.right :
             node.kind === SyntaxKind.ImportType ? node :
-            node.kind === SyntaxKind.BindingElement && node.propertyName ? node.propertyName : node.name;
+            node.kind === SyntaxKind.BindingElement && node.propertyName ? node.propertyName :
+            node.kind === SyntaxKind.ElementAccessExpression ? node.expression : node.name;
 
         return checkPropertyAccessibilityAtLocation(node, isSuper, writing, type, prop, errorNode);
     }
@@ -34740,7 +34741,12 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             }
         }
         const indexedAccessType = getIndexedAccessTypeOrUndefined(objectType, effectiveIndexType, accessFlags, node) || errorType;
-        return checkIndexedAccessIndexType(getFlowTypeOfAccessExpression(node, getNodeLinks(node).resolvedSymbol, indexedAccessType, indexExpression, checkMode), node);
+        const symbol = getNodeLinks(node).resolvedSymbol;
+        if (symbol) {
+            const apparentType = getApparentType(objectType);
+            checkPropertyAccessibility(node, node.expression.kind === SyntaxKind.SuperKeyword, !!(accessFlags & AccessFlags.Writing), apparentType, symbol);
+        }
+        return checkIndexedAccessIndexType(getFlowTypeOfAccessExpression(node, symbol, indexedAccessType, indexExpression, checkMode), node);
     }
 
     function callLikeExpressionMayHaveTypeArguments(node: CallLikeExpression): node is CallExpression | NewExpression | TaggedTemplateExpression | JsxOpeningElement {

tests/baselines/reference/keyofAndIndexedAccess.errors.txt

@@ -1,3 +1,5 @@
+keyofAndIndexedAccess.ts(176,16): error TS2445: Property 'y' is protected and only accessible within class 'C' and its subclasses.
+keyofAndIndexedAccess.ts(177,16): error TS2341: Property 'z' is private and only accessible within class 'C'.
 keyofAndIndexedAccess.ts(205,24): error TS2322: Type 'T[keyof T]' is not assignable to type 'object'.
   Type 'T[string] | T[number] | T[symbol]' is not assignable to type 'object'.
     Type 'T[string]' is not assignable to type 'object'.
@@ -15,7 +17,7 @@ keyofAndIndexedAccess.ts(318,5): error TS2322: Type 'T[K]' is not assignable to
       Type 'T[string]' is not assignable to type '{}'.
 
 
-==== keyofAndIndexedAccess.ts (5 errors) ====
+==== keyofAndIndexedAccess.ts (7 errors) ====
     class Shape {
         name: string;
         width: number;
@@ -192,7 +194,11 @@ keyofAndIndexedAccess.ts(318,5): error TS2322: Type 'T[K]' is not assignable to
         type Z = C["z"];
         let x: X = c["x"];
         let y: Y = c["y"];
+                   ~
+!!! error TS2445: Property 'y' is protected and only accessible within class 'C' and its subclasses.
         let z: Z = c["z"];
+                   ~
+!!! error TS2341: Property 'z' is private and only accessible within class 'C'.
     }
 
     function f50<T>(k: keyof T, s: string) {

tests/baselines/reference/superElementAccess.errors.txt

@@ -0,0 +1,56 @@
+superElementAccess.ts(21,9): error TS2340: Only public and protected methods of the base class are accessible via the 'super' keyword.
+superElementAccess.ts(23,9): error TS2341: Property 'p1' is private and only accessible within class 'MyBase'.
+superElementAccess.ts(25,18): error TS2340: Only public and protected methods of the base class are accessible via the 'super' keyword.
+superElementAccess.ts(27,18): error TS2340: Only public and protected methods of the base class are accessible via the 'super' keyword.
+superElementAccess.ts(31,9): error TS2340: Only public and protected methods of the base class are accessible via the 'super' keyword.
+superElementAccess.ts(33,17): error TS2340: Only public and protected methods of the base class are accessible via the 'super' keyword.
+
+
+==== superElementAccess.ts (6 errors) ====
+    class MyBase {
+        m1(a: string) { return a; }
+        private p1() { }
+        m2: () => void = function () { }
+        d1: number = 42;
+        private d2: number = 42;
+        get value() {return 0 }
+        set value(v: number) { }
+    }
+
+
+    class MyDerived extends MyBase {
+
+        foo() {
+            super["m1"]("hi");                                     // Should be allowed, method on base prototype
+
+            var l2 = super["m1"].bind(this);                       // Should be allowed, can access properties as well as invoke
+
+            var x: (a: string) => string = super["m1"];            // Should be allowed, can assign to var with compatible signature
+
+            super["m2"].bind(this);                                // Should error, instance property, not a public instance member function
+            ~~~~~
+!!! error TS2340: Only public and protected methods of the base class are accessible via the 'super' keyword.
+
+            super["p1"]();                                         // Should error, private not public instance member function
+            ~~~~~
+!!! error TS2341: Property 'p1' is private and only accessible within class 'MyBase'.
+
+            var l1 = super["d1"];                                  // Should error, instance data property not a public instance member function
+                     ~~~~~
+!!! error TS2340: Only public and protected methods of the base class are accessible via the 'super' keyword.
+
+            var l1 = super["d2"];                                  // Should error, instance data property not a public instance member function
+                     ~~~~~
+!!! error TS2340: Only public and protected methods of the base class are accessible via the 'super' keyword.
+
+            super["m1"] = function (a: string) { return ""; };     // Should be allowed, we will not restrict assignment
+
+            super["value"] = 0;                                    // Should error, instance data property not a public instance member function
+            ~~~~~
+!!! error TS2340: Only public and protected methods of the base class are accessible via the 'super' keyword.
+
+            var z = super["value"];                                // Should error, instance data property not a public instance member function
+                    ~~~~~
+!!! error TS2340: Only public and protected methods of the base class are accessible via the 'super' keyword.
+        }
+    }

tests/baselines/reference/superElementAccess.types

@@ -73,7 +73,9 @@ class MyDerived extends MyBase {
 
         var l2 = super["m1"].bind(this);                       // Should be allowed, can access properties as well as invoke
 >l2 : any
+>   : ^^^
 >super["m1"].bind(this) : any
+>                       : ^^^
 >super["m1"].bind : (this: Function, thisArg: any, ...argArray: any[]) => any
 >                 : ^    ^^        ^^       ^^   ^^^^^        ^^     ^^^^^   
 >super["m1"] : (a: string) => string
@@ -101,6 +103,7 @@ class MyDerived extends MyBase {
 
         super["m2"].bind(this);                                // Should error, instance property, not a public instance member function
 >super["m2"].bind(this) : any
+>                       : ^^^
 >super["m2"].bind : (this: Function, thisArg: any, ...argArray: any[]) => any
 >                 : ^    ^^        ^^       ^^   ^^^^^        ^^     ^^^^^   
 >super["m2"] : () => void