fix(checker): Allow element access expressions in computed property names if argument is literal

src/compiler/checker.ts

@@ -742,6 +742,7 @@ import {
     isShorthandAmbientModuleSymbol,
     isShorthandPropertyAssignment,
     isSideEffectImport,
+    isSignedNumericLiteral,
     isSingleOrDoubleQuote,
     isSourceFile,
     isSourceFileJS,
@@ -13720,14 +13721,25 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             && isTypeUsableAsIndexSignature(isComputedPropertyName(node) ? checkComputedPropertyName(node) : checkExpressionCached((node as ElementAccessExpression).argumentExpression));
     }
 
-    function isLateBindableAST(node: DeclarationName) {
-        if (!isComputedPropertyName(node) && !isElementAccessExpression(node)) {
-            return false;
+    function isLateBindableExpression(expr: Expression): boolean {
+        while (isElementAccessExpression(expr)) {
+            const argument = skipParentheses(expr.argumentExpression);
+            if (!isStringOrNumericLiteralLike(argument) && !isSignedNumericLiteral(argument)) return false;
+            expr = expr.expression;
         }
-        const expr = isComputedPropertyName(node) ? node.expression : node.argumentExpression;
         return isEntityNameExpression(expr);
     }
 
+    function isLateBindableAST(node: DeclarationName) {
+        if (isComputedPropertyName(node)) {
+            return isLateBindableExpression(node.expression);
+        }
+        else if (isElementAccessExpression(node)) {
+            return isLateBindableExpression(node.argumentExpression);
+        }
+        return false;
+    }
+
     function isTypeUsableAsIndexSignature(type: Type): boolean {
         return isTypeAssignableTo(type, stringNumberSymbolType);
     }

tests/cases/compiler/enumKeysInTypeLiteral.ts

@@ -0,0 +1,29 @@
+
+enum Type {
+  Foo = 'foo',
+  '3x14' = '3x14'
+}
+
+type TypeMap = {
+  [Type.Foo]: 1;
+  [Type['3x14']]: 2;
+}
+
+const t: TypeMap = {
+    'foo': 1,
+    '3x14': 2
+};
+
+enum Numeric {
+    Negative = -1,
+    Zero = 0
+}
+
+type NumericMap = {
+    // Valid: Accessing enum member via string literal for the name
+    [Numeric['Negative']]: number; 
+    [Numeric['Zero']]: number;
+    // Valid: Parenthesized access
+    [Numeric[('Negative')]]: number;
+}
+