fix(54694): Class incorrectly implements interface generated with template string literal mapped type (#54715)

src/compiler/checker.ts

@@ -335,6 +335,7 @@ import {
     getParseTreeNode,
     getPropertyAssignmentAliasLikeExpression,
     getPropertyNameForPropertyNameNode,
+    getPropertyNameFromType,
     getResolutionDiagnostic,
     getResolutionModeOverrideForClause,
     getResolvedExternalModuleName,
@@ -729,6 +730,7 @@ import {
     isTypeQueryNode,
     isTypeReferenceNode,
     isTypeReferenceType,
+    isTypeUsableAsPropertyName,
     isUMDExportSymbol,
     isValidBigIntString,
     isValidESSymbolDeclaration,
@@ -12286,13 +12288,6 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         return type as InterfaceTypeWithDeclaredMembers;
     }
 
-    /**
-     * Indicates whether a type can be used as a property name.
-     */
-    function isTypeUsableAsPropertyName(type: Type): type is StringLiteralType | NumberLiteralType | UniqueESSymbolType {
-        return !!(type.flags & TypeFlags.StringOrNumberLiteralOrUnique);
-    }
-
     /**
      * Indicates whether a declaration name is definitely late-bindable.
      * A declaration name is only late-bindable if:
@@ -12338,19 +12333,6 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         return isDynamicName(node) && !isLateBindableName(node);
     }
 
-    /**
-     * Gets the symbolic name for a member from its type.
-     */
-    function getPropertyNameFromType(type: StringLiteralType | NumberLiteralType | UniqueESSymbolType): __String {
-        if (type.flags & TypeFlags.UniqueESSymbol) {
-            return (type as UniqueESSymbolType).escapedName;
-        }
-        if (type.flags & (TypeFlags.StringLiteral | TypeFlags.NumberLiteral)) {
-            return escapeLeadingUnderscores("" + (type as StringLiteralType | NumberLiteralType).value);
-        }
-        return Debug.fail();
-    }
-
     /**
      * Adds a declaration to a late-bound dynamic member. This performs the same function for
      * late-bound members that `addDeclarationToSymbol` in binder.ts performs for early-bound

src/compiler/utilities.ts

@@ -416,6 +416,7 @@ import {
     noop,
     normalizePath,
     NoSubstitutionTemplateLiteral,
+    NumberLiteralType,
     NumericLiteral,
     ObjectFlags,
     ObjectFlagsType,
@@ -494,6 +495,7 @@ import {
     stringContains,
     StringLiteral,
     StringLiteralLike,
+    StringLiteralType,
     stringToToken,
     SuperCall,
     SuperExpression,
@@ -544,6 +546,7 @@ import {
     TypeReferenceNode,
     unescapeLeadingUnderscores,
     UnionOrIntersectionTypeNode,
+    UniqueESSymbolType,
     UserPreferences,
     ValidImportTypeNode,
     VariableDeclaration,
@@ -10313,3 +10316,25 @@ export function getTextOfJsxNamespacedName(node: JsxNamespacedName) {
 export function intrinsicTagNameToString(node: Identifier | JsxNamespacedName) {
     return isIdentifier(node) ? idText(node) : getTextOfJsxNamespacedName(node);
 }
+
+/**
+ * Indicates whether a type can be used as a property name.
+ * @internal
+ */
+export function isTypeUsableAsPropertyName(type: Type): type is StringLiteralType | NumberLiteralType | UniqueESSymbolType {
+    return !!(type.flags & TypeFlags.StringOrNumberLiteralOrUnique);
+}
+
+/**
+ * Gets the symbolic name for a member from its type.
+ * @internal
+ */
+export function getPropertyNameFromType(type: StringLiteralType | NumberLiteralType | UniqueESSymbolType): __String {
+    if (type.flags & TypeFlags.UniqueESSymbol) {
+        return (type as UniqueESSymbolType).escapedName;
+    }
+    if (type.flags & (TypeFlags.StringLiteral | TypeFlags.NumberLiteral)) {
+        return escapeLeadingUnderscores("" + (type as StringLiteralType | NumberLiteralType).value);
+    }
+    return Debug.fail();
+}