prefer-promise-reject-errors

A promise rejected with a string or a plain object has no stack trace, so you can't see where it failed. The code that catches it and reads error.message gets undefined.

The rule checks Promise.reject() and the reject function of new Promise((resolve, reject) => ...). It reports a reason that can't be an Error: a literal, an object literal, undefined, or nothing. A variable or a call's result isn't reported, because the rule can't tell what it holds.

Configure

Off by default. To turn it on:

[lint.rules]
"prefer-promise-reject-errors" = "error" # or "warn"

Every option, set to its default:

[lint.rules]
"prefer-promise-reject-errors" = ["error", {
  allowEmptyReject = false,
}]

Examples

Reported:

Promise.reject("User not found");

new Promise((resolve, reject) => {
  reject({ code: 404 });
});

Not reported:

Promise.reject(new Error("User not found"));

new Promise((resolve, reject) => {
  reject(new RangeError("Page out of range"));
});

Promise.reject(reason);

Options

Option	Default	What it does
allowEmptyReject	false	Allow a rejection with no argument.

Promise.reject();

Writing out undefined is still reported:

Promise.reject(undefined);