Might Fail
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Getting Started

Change the way you catch errors

That's it, that's all this library helps you do. No major re-writes for your code base, no major changes at all. Just start handling your errors in a much better way.

You still throw errors or let other libraries throw errors. Just stop using try, catch, finally and use mightFail or mightFailSync instead.

catch Sucks. Guarding is Good.

Guarding allows you to handle your errors early and return from the function early, making them more readable and easier to reason about.

const [ networkError, result ] = await mightFail(fetch("/posts"));
// guard against a network error
if (networkError) {
  return;
}
// guard against an error response from the server
if (!result.ok) {
  return;
}
const [ convertToJSONError, posts ] = await mightFail(
  result.json()
);
// guard against an error converting the response to JSON
if (convertToJSONError) {
  return;
}

// success case, unnested and at the bottom of the function
posts.map((post) => console.log(post.title));
const [ networkError, result ] = await mightFail(fetch("/posts"));
// guard against a network error
if (networkError) {
  return;
}
// guard against an error response from the server
if (!result.ok) {
  return;
}
const [ convertToJSONError, posts ] = await mightFail(
  result.json()
);
// guard against an error converting the response to JSON
if (convertToJSONError) {
  return;
}

// success case, unnested and at the bottom of the function
posts.map((post) => console.log(post.title));
const [ networkError, result ] = await mightFail(fetch("/posts"));
// guard against a network error
if (networkError) {
  return;
}
// guard against an error response from the server
if (!result.ok) {
  return;
}
const [ convertToJSONError, posts ] = await mightFail(
  result.json()
);
// guard against an error converting the response to JSON
if (convertToJSONError) {
  return;
}

// success case, unnested and at the bottom of the function
posts.map((post) => console.log(post.title));
const [ networkError, result ] = await mightFail(fetch("/posts"));
// guard against a network error
if (networkError) {
  return;
}
// guard against an error response from the server
if (!result.ok) {
  return;
}
const [ convertToJSONError, posts ] = await mightFail(
  result.json()
);
// guard against an error converting the response to JSON
if (convertToJSONError) {
  return;
}

// success case, unnested and at the bottom of the function
posts.map((post) => console.log(post.title));

The success case is now the only code that is not nested in another block. It's also at the very bottom of the function making it easy to find.