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bind

TS JS Deno

Creates a function that invokes fn with a given context, optionally adding any additional supplied parameters to the beginning of the arguments.

Return a function that uses Function.prototype.apply() to apply the given context to fn. Use Array.prototype.concat() to prepend any additional supplied parameters to the arguments.

typescript
export const bind =
  <T = any>(fn: (...args: any[]) => any, context: T, ...boundArgs: any[]) =>
  (...args: any[]) =>
    fn.apply(context, [...boundArgs, ...args]);

TS: You need to bind this type

typescript
const freddy = { user: "fred" };
function greet(this: typeof freddy, greeting: string, punctuation: string) {
  return greeting + " " + this.user + punctuation;
}
const freddyBound = bind(greet, freddy);
console.log(freddyBound("hi", "!")); // 'hi fred!'

JS Version:

function greet(greeting, punctuation) {
  return greeting + " " + this.user + punctuation;
}
const freddy = { user: "fred" };
const freddyBound = bind(greet, freddy);
console.log(freddyBound("hi", "!")); // 'hi fred!'