18 lines
470 B
JavaScript
18 lines
470 B
JavaScript
const expect = require('expect');
|
|
const {nthArg} = require('./_30s.js');
|
|
|
|
test('nthArg is a Function', () => {
|
|
expect(nthArg).toBeInstanceOf(Function);
|
|
});
|
|
const third = nthArg(2);
|
|
test('Returns the nth argument', () => {
|
|
expect(third(1, 2, 3)).toBe(3);
|
|
});
|
|
test('Returns undefined if arguments too few', () => {
|
|
expect(third(1, 2)).toBe(undefined);
|
|
});
|
|
const last = nthArg(-1);
|
|
test('Works for negative values', () => {
|
|
expect(last(1, 2, 3, 4, 5)).toBe(5);
|
|
});
|