Move to typescript

[alexreardon]

Here is what I am thinking so far:

export type EqualityFn = (newArgs: unknown[], lastArgs: unknown[]) => boolean;

function areInputsEqual(
  newInputs: unknown[],
  lastInputs: unknown[],
): boolean {
  // no checks needed if the inputs length has changed
  if (newInputs.length !== lastInputs.length) {
    return false;
  }
  // Using for loop for speed. It generally performs better than array.every
  // https://github.com/alexreardon/memoize-one/pull/59

  for (let i = 0; i < newInputs.length; i++) {
    // using shallow equality check
    if (newInputs[i] !== lastInputs[i]) {
      return false;
    }
  }
  return true;
}


export default function memoizeOne<ResultFn extends (this: unknown, ...newArgs: unknown[]) => ReturnType<ResultFn>>(
  this: unknown,
  resultFn: ResultFn,
  isEqual: EqualityFn = areInputsEqual,
): ResultFn {
  let lastThis: unknown;
  let lastArgs: unknown[] = [];
  let lastResult: ReturnType<ResultFn>;
  let calledOnce: boolean = false;

  // breaking cache when context (this) or arguments change
  function memoized(this: unknown, ...newArgs: unknown[]): ReturnType<ResultFn> {
    if (calledOnce && lastThis === this && isEqual(newArgs, lastArgs)) {
      return lastResult;
    }

    // Throwing during an assignment aborts the assignment: https://codepen.io/alexreardon/pen/RYKoaz
    // Doing the lastResult assignment first so that if it throws
    // nothing will be overwritten
    lastResult = resultFn.apply(this, newArgs);
    calledOnce = true;
    lastThis = this;
    lastArgs = newArgs;
    return lastResult;
  }

  return (memoized as ResultFn);
}

playground

[alexreardon]

Need to consider what build changes to be made, and how to continue to support flow consumers

[TrySound]

Same as before
https://github.com/renatorib/react-powerplug/blob/master/package.json#L16
https://github.com/renatorib/react-powerplug/tree/master/src

Or just copy this flow file to the dist.