node/test/parallel/test-assert-fail.js
Rich Trott 758b8b6e5d assert: improve assert.fail() API
assert.fail() has two possible function signatures, both of which are
not intuitive. It virtually guarantees that people who try to use
assert.fail() without carefully reading the docs will end up using it
incorrectly.

This change maintains backwards compatibility with the two valid uses
(arguments 1 2 and 4 supplied but argument 3 falsy, and argument 3
supplied but arguments 1 2 and 4 all falsy) but also adds the far more
intuitive first-argument-only and first-two-arguments-only
possibilities.

assert.fail('boom');
// AssertionError: boom

assert.fail('a', 'b');
// AssertionError: 'a' != 'b'

PR-URL: https://github.com/nodejs/node/pull/12293
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
2017-04-12 14:25:22 -07:00

34 lines
773 B
JavaScript

'use strict';
require('../common');
const assert = require('assert');
// no args
assert.throws(
() => { assert.fail(); },
/^AssertionError: undefined undefined undefined$/
);
// one arg = message
assert.throws(
() => { assert.fail('custom message'); },
/^AssertionError: custom message$/
);
// two args only, operator defaults to '!='
assert.throws(
() => { assert.fail('first', 'second'); },
/^AssertionError: 'first' != 'second'$/
);
// three args
assert.throws(
() => { assert.fail('ignored', 'ignored', 'another custom message'); },
/^AssertionError: another custom message$/
);
// no third arg (but a fourth arg)
assert.throws(
() => { assert.fail('first', 'second', undefined, 'operator'); },
/^AssertionError: 'first' operator 'second'$/
);