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node: add util.callbackify (denoland/deno#5415)
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This adds [Node's `util.callbackify`][0] to `node/util.ts`.

I lifted most of this from the [original Node source code][1] (and [its
tests][2]). I tried to make minimal modifications to the source.

I made a few arbitrary decisions:

- I was unable to do the function's types elegantly. I made overloads
  for functions that have 0 to 5 (inclusive) arguments, excluding the
  callback. I would love to know a better way to do this. (It seems that
  the folks at DefinitelyTyped [were also stumped][3], though maybe
  their solution is deliberate.)
- There are a few edge cases that cause custom Node errors to be
  produced. Instead of re-implementing those errors completely, I
  created simplified classes. These are mostly correct but are not
  identical to the real Node errors.
- The tests implement a possibly-arcane `TestQueue` class. I originally
  used a lot of inline promises but found it too repetitive.

Closes [denoland/deno#5366][4].

[0]: https://nodejs.org/api/util.html#util_util_callbackify_original
[1]: https://github.com/nodejs/node/blob/47804933012841f2dc90626bdcc161adf34569a5/lib/util.js#L183-L226
[2]: https://github.com/nodejs/node/blob/47804933012841f2dc90626bdcc161adf34569a5/test/parallel/test-util-callbackify.js
[3]: https://github.com/DefinitelyTyped/DefinitelyTyped/blob/7d24857ddb07ab637dfa8c477d13352f8a8206fc/types/node/util.d.ts#L61-L84
[4]: denoland/deno#5366
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EvanHahn authored and caspervonb committed Jan 24, 2021
1 parent bbf73f7 commit 18cc87b
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125 changes: 125 additions & 0 deletions node/_util/_util_callbackify.ts
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// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
//
// Adapted from Node.js. Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

// These are simplified versions of the "real" errors in Node.
class NodeFalsyValueRejectionError extends Error {
public reason: unknown;
public code = "ERR_FALSY_VALUE_REJECTION";
constructor(reason: unknown) {
super("Promise was rejected with falsy value");
this.reason = reason;
}
}
class NodeInvalidArgTypeError extends TypeError {
public code = "ERR_INVALID_ARG_TYPE";
constructor(argumentName: string) {
super(`The ${argumentName} argument must be of type function.`);
}
}

type Callback<ResultT> =
| ((err: Error) => void)
| ((err: null, result: ResultT) => void);

function callbackify<ResultT>(
fn: () => PromiseLike<ResultT>
): (callback: Callback<ResultT>) => void;
function callbackify<ArgT, ResultT>(
fn: (arg: ArgT) => PromiseLike<ResultT>
): (arg: ArgT, callback: Callback<ResultT>) => void;
function callbackify<Arg1T, Arg2T, ResultT>(
fn: (arg1: Arg1T, arg2: Arg2T) => PromiseLike<ResultT>
): (arg1: Arg1T, arg2: Arg2T, callback: Callback<ResultT>) => void;
function callbackify<Arg1T, Arg2T, Arg3T, ResultT>(
fn: (arg1: Arg1T, arg2: Arg2T, arg3: Arg3T) => PromiseLike<ResultT>
): (arg1: Arg1T, arg2: Arg2T, arg3: Arg3T, callback: Callback<ResultT>) => void;
function callbackify<Arg1T, Arg2T, Arg3T, Arg4T, ResultT>(
fn: (
arg1: Arg1T,
arg2: Arg2T,
arg3: Arg3T,
arg4: Arg4T
) => PromiseLike<ResultT>
): (
arg1: Arg1T,
arg2: Arg2T,
arg3: Arg3T,
arg4: Arg4T,
callback: Callback<ResultT>
) => void;
function callbackify<Arg1T, Arg2T, Arg3T, Arg4T, Arg5T, ResultT>(
fn: (
arg1: Arg1T,
arg2: Arg2T,
arg3: Arg3T,
arg4: Arg4T,
arg5: Arg5T
) => PromiseLike<ResultT>
): (
arg1: Arg1T,
arg2: Arg2T,
arg3: Arg3T,
arg4: Arg4T,
arg5: Arg5T,
callback: Callback<ResultT>
) => void;

// eslint-disable-next-line @typescript-eslint/no-explicit-any
function callbackify(original: any): any {
if (typeof original !== "function") {
throw new NodeInvalidArgTypeError('"original"');
}

const callbackified = function (this: unknown, ...args: unknown[]): void {
const maybeCb = args.pop();
if (typeof maybeCb !== "function") {
throw new NodeInvalidArgTypeError("last");
}
const cb = (...args: unknown[]): void => {
maybeCb.apply(this, args);
};
original.apply(this, args).then(
(ret: unknown) => {
setTimeout(cb.bind(this, null, ret), 0);
},
(rej: unknown) => {
rej = rej || new NodeFalsyValueRejectionError(rej);
queueMicrotask(cb.bind(this, rej));
}
);
};

const descriptors = Object.getOwnPropertyDescriptors(original);
// It is possible to manipulate a functions `length` or `name` property. This
// guards against the manipulation.
if (typeof descriptors.length.value === "number") {
descriptors.length.value++;
}
if (typeof descriptors.name.value === "string") {
descriptors.name.value += "Callbackified";
}
Object.defineProperties(callbackified, descriptors);
return callbackified;
}

export { callbackify };
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