no-promise-reject.md

Disallow rejecting Promises (no-promise-reject)

This rule disallows use of Promise.reject().

We don't recommend this rule but it's there for those who want it.

Rule Details

You can view a Promise as a result object with built-in error (something like { value: T } | { error: Error }) in which case a rejected Promise can be viewed as a returned result and thus fits with functional programming. You can also view a rejected promise as something similar to an exception and as such something that does not fit with functional programming. If your view is the latter you can use the no-promise-reject rule to disallow rejected promises.

Examples of incorrect code for this rule:

/* eslint functional/no-promise-reject: "error" */

async function divide(x, y) {
  const [xv, yv] = await Promise.all([x, y]);

  return yv === 0
    ? Promise.reject(new Error("Cannot divide by zero."))
    : xv / yv;
}

Examples of correct code for this rule:

/* eslint functional/no-promise-reject: "error" */

async function divide(x, y) {
  const [xv, yv] = await Promise.all([x, y]);

  return yv === 0
    ? new Error("Cannot divide by zero.")
    : xv / yv;
}

Options

The rule does not accept any options.