Grip

Simplified result/error handling for JavaScript. Grip always returns a consistent call result ready to be handled. It makes the control flow similar to that of Golang, but doesn't force you to make additional null checks or create transitional variables to hold error results.

Install

bun add github:nesterow/grip # or pnpm

Usage

The grip function accepts a function or a promise and returns a result with return value and status. The result can be hadled as either an object or a tuple.

import { grip } from '@nesterow/grip';

Handle result as an object:

The result can be handled as an object: {value, status, Ok(), Fail(), Of(type)}

const res = await grip(
  fetch('https://api.example.com')
);

if (res.Fail()) {
    handleErrorProperly();
    return;
}

const json = await grip(
  res.value.json()
);

if (json.Of(SyntaxError)) {
    handleJsonParseError();
    return;
}

Handle result as a tuple:

The result can also be received as a tuple if you want to handle errors in Go'ish style:

const [res, fetchStatus] = await grip(
  fetch('https://api.example.com')
);
if (fetchStatus.Fail()) {
    handleErrorProperly();
    return;
}

const [json, parseStatus] = await grip(
  res.json()
);
if (parseStatus.Of(SyntaxError)) {
    handleJsonParseError();
    return;
}

Handle functions:

Grip can also handle functions:

const [result, status] = grip(() => "ok");
// result = "ok"

const [result1, status1] = grip(() => {
  if (1) throw new Error("error")
});
// result1 = null
// status.Of(Error) = true

Handle generators

Generators can be handled using the Iter() method:

const res = grip(async function* () {
  for (let i = 0; i < 3; i++) {
    if (i == 2) throw new Error("2");
    yield i;
  }
});
for await (let [value, status] of res.Iter()) {
  if (status.Of(Error)) {
    // handle error properly
    break;
  }
  // typeof value === "number"
  console.log(value)
}

License

MIT

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