require-throws-expectation

📝 Require an error matcher for assert.throws()/assert.rejects().

💼 This rule is enabled in the following configs: ✅ recommended, ☑️ unopinionated.

assert.throws(fn) and assert.rejects(asyncFn) with no second argument pass for any thrown value. That makes the assertion weak: a typo, a ReferenceError, or an unrelated failure all satisfy it, so the test can pass for the wrong reason. Pass an error matcher — an error class, a RegExp for the message, a validation object, or a validation function — to assert that the expected error is thrown.

This rule reports a single-argument assert.throws()/assert.rejects(). A string second argument is reported by no-assert-throws-string instead.

Examples

import assert from 'node:assert';

// ❌
assert.throws(() => parse(input));
await assert.rejects(() => load(url));

// ✅
assert.throws(() => parse(input), SyntaxError);
await assert.rejects(() => load(url), {code: 'ENOENT'});