assert

    assert.fail(actual, expected, message, operator)
    assert(value[, message]), assert.ok(value[, message])
    assert.equal(actual, expected[, message])
    assert.notEqual(actual, expected[, message])
    assert.deepEqual(actual, expected[, message])
    assert.notDeepEqual(actual, expected[, message])
    assert.strictEqual(actual, expected[, message])
    assert.notStrictEqual(actual, expected[, message])
    assert.deepStrictEqual(actual, expected[, message])
    assert.notDeepStrictEqual(actual, expected[, message])
    assert.throws(block[, error][, message])
    assert.doesNotThrow(block[, message])
    assert.ifError(value)