import {mergeLeft} from './mergeLeft'
const obj = { foo: 1, bar: 2,}
test('happy', () => { expect(mergeLeft({bar: 20}, obj)).toEqual({ foo: 1, bar: 20, })})
test('curry', () => { expect(mergeLeft({baz: 3})(obj)).toEqual({ foo: 1, bar: 2, baz: 3, })})
test('when undefined or null instead of object', () => { expect(mergeLeft(null, undefined)).toEqual({}) expect(mergeLeft(obj, null)).toEqual(obj) expect(mergeLeft(obj, undefined)).toEqual(obj) expect(mergeLeft(undefined, obj)).toEqual(obj)})