If you're looking for a solution where you can declare an existing function without defining an expression, check out this article: . Rather than creating a new function, the goal is to declare the existing function in a similar manner without using the squiggle syntax. Here's an example, even though the syntax is not valid:
function f() {} as any;
f.someProperty = "I want to do this without squizzle in vscode";
The main objective is to find a way to avoid using the squiggle syntax in VScode for declaring existing functions.