import { expect } from 'chai'; import u from '../lib'; describe('updeep', () => { it('does not change anything if no updates are specified', () => { const object = { foo: 3, bar: [7, 5] }; const result = u({}, object); expect(result).to.equal(object); }); it('can update with fixed values', () => { const object = { foo: 3, bar: [7, 5] }; const result = u({ foo: 4 }, object); expect(result).to.deep.equal({ foo: 4, bar: [7, 5] }); }); it('returns the same instance if an update doesn\'t make changes', () => { const object = { foo: 3 }; const result = u({ foo: 3 }, object); expect(result).to.equal(object); }); it('can update a nested structure', () => { const object = { foo: { bar: 7, bam: 3 }, baz: 32 }; const result = u({ foo: { bar: 8 } }, object); expect(result).to.deep.equal({ foo: { bar: 8, bam: 3 }, baz: 32 }); }); it('can update arrays', () => { const object = [1, 2, 3]; const result = u({ 1: 7 }, object); expect(result).to.deep.equal([1, 7, 3]); }); it('replaces the object outright if updates are a constant', () => { expect(u(3, {})).to.equal(3); expect(u(null, {})).to.be.null; }); it('can add an element to an array', () => { const object = []; const result = u({ 0: 3 }, object); expect(result).to.eql([3]); }); it('can update nested arrays', () => { const object = { foo: [1, 2, 3], bar: 9 }; const result = u({ foo: { 1: 7 } }, object); expect(result).to.deep.equal({ foo: [1, 7, 3], bar: 9 }); }); it('can use functions to update values', () => { const inc = (i) => i + 1; const object = { foo: 3, bar: 4, baz: 7 }; const result = u({ foo: inc, bar: inc }, object); expect(result).to.deep.equal({ foo: 4, bar: 5, baz: 7 }); }); it('can be partially applied', () => { const inc = (i) => i + 1; const object = { foo: 3 }; const incFoo = u({ foo: inc }); const result = incFoo(object); expect(result).to.deep.equal({ foo: 4 }); }); it('passes additional arguments on to updates if it is a function', () => { const func = (_, x) => x; const result = u(func, 0, 4); expect(result).to.equal(4); }); it('can update if the value is an array', () => { const object = {}; const result = u({ foo: [0, 1] }, object); expect(result).to.deep.equal({ foo: [0, 1] }); }); it('can update when original object is undefined', () => { const result = u({ foo: [0, 1] }, undefined); expect(result).to.deep.equal({ foo: [0, 1] }); }); it('can take a function as the updater', () => { const result = u(i => i + 1, 7); expect(result).to.eql(8); }); it('deeply freezes the result', () => { const result = u({ foo: { bar: 3 } }, { foo: { bar: 0 } }); expect(Object.isFrozen(result)).to.be.true; expect(Object.isFrozen(result.foo)).to.be.true; }); it('assigns null values', () => { expect(u({isNull: null}, {})).to.eql({isNull: null}); }); it('can use a placeholder to partially apply', () => { function increment(i) { return i + 1; } const updateJoe = u(u._, { name: 'Joe Merrill', age: 21 }); const result = updateJoe({ age: increment }); expect(result).to.eql({ name: 'Joe Merrill', age: 22 }); }); it('defaults to an empty object when null or undefined', () => { let result = u({ a: { b: 0 } }, { a: null }); expect(result).to.eql({ a: { b: 0 } }); result = u({ a: { b: 0 } }, { a: undefined }); expect(result).to.eql({ a: { b: 0 } }); result = u({ a: { b: 0 } }, { }); expect(result).to.eql({ a: { b: 0 } }); }); it('preserves empty objects when empty updates are specified', () => { const result = u({ a: {} }, {}); expect(result).to.eql({ a: {} }); }); });