optional-require

Optional Require

node.js require that let you handle module not found error without try/catch. Allows you to gracefully require a module only if it exists and contains no error.

Why not try/catch?

So why not just do:

let some;
try {
  some = require("some-optional-module");
} catch {
  // do nothing
}

1. You need to keep the variable outside: let some before try/catch
2. If "some-optional-module" contains error itself, above code will silently ignore it, leaving you, and more importantly, your users, puzzling on why it's not working.

Usage

TypeScript:

import { optionalRequire } from "optional-require";

const some = optionalRequire("some-optional-module");

JavaScript:

const { optionalRequire } = require("optional-require");

const foo = optionalRequire("foo") || {};
const bar = optionalRequire("bar", true); // true enables console.log a message when not found
const xyz = optionalRequire("xyz", "test"); // "test" enables console.log a message with "test" added.
const fbPath = optionalRequire.resolve("foo", "foo doesn't exist");
// relative module path works - *but* you need to pass in `require` from your file
const rel = optionalRequire("../foo/bar", { require });

Binding require

The default optionalRequire uses require from the context of this module. While you can pass in your require in options, if you want to create your own function that's bound to your require, you can do it with makeOptionalRequire:

import { makeOptionalRequire } from "optional-require";

const optionalRequire = makeOptionalRequire(require);

// now you can optional require files in same dir as your file
const myModule = optionalRequire("./my-module");

Legacy Usage

In older versions, this module exports makeOptionalRequire directly and this is the legacy usage in JavaScript, which is still supported:

const optionalRequire = require("optional-require")(require);

const foo = optionalRequire("foo") || {};
const bar = optionalRequire("bar", true); // true enables console.log a message when not found
const xyz = optionalRequire("xyz", "test"); // "test" enables console.log a message with "test" added.
const fbPath = optionalRequire.resolve("foo", "foo doesn't exist");
const rel = optionalRequire("../foo/bar"); // relative module path works

API

https://jchip.github.io/optional-require/modules.html#optionalrequire

LICENSE

Apache-2.0 © Joel Chen