feat(language-service): completions support for tuple array (#33928)

PR Close #33928

packages/language-service/src/symbols.ts

@@ -116,9 +116,12 @@ export interface Symbol {
 
   /**
    * Return the type of the expression if this symbol is indexed by `argument`.
+   * Sometimes we need the key of arguments to get the type of the expression, for example
+   * in the case of tuples (`type Example = [string, number]`).
+   * [string, number]).
    * If the symbol cannot be indexed, this method should return `undefined`.
    */
-  indexed(argument: Symbol): Symbol|undefined;
+  indexed(argument: Symbol, key?: any): Symbol|undefined;
 }
 
 /**
@@ -349,4 +352,4 @@ export interface SymbolQuery {
    * Return the span of the narrowest non-token node at the given location.
    */
   getSpanAt(line: number, column: number): Span|undefined;
-}
+}