keyu/test/collections.js

const assert = require('assert');
const {map,filter} = require('../collections');

const incrementBy = value => data => value + data;
const identity = x => x;
const greaterThan = x => data => data > x;
const get = key => data => data[key];

describe('Collections', function() {
  describe('#map()', function() {
    it('should return same object given identity', function(){
      let a = {a:1, b:2};
      assert.deepEqual(a.map(identity),{a:1,b:2});
      assert.deepEqual(map(identity,a),{a:1,b:2});
    });
    it('should return incrementBy(1) all properties', function(){
      let a = {a:1, b:2};
      assert.deepEqual(a.map(incrementBy(1)),{a:2,b:3});
      assert.deepEqual(map(incrementBy(1),a),{a:2,b:3});
    });
    it('should return the first level', function(){
      let a = {a:{b:1},b:{b:2}};
      assert.deepEqual(a.map(get('b')),{a:1,b:2});
      assert.deepEqual(map(get('b'),a),{a:1,b:2});
    });
    it('should return empty object if empty object', function(){
      let a = {};
      assert.deepEqual(a.map(incrementBy(1)),{});
      assert.deepEqual(map(incrementBy(1),a),{});
    });
  });
  describe('#filter()', function() {
    it('should return same object given identity', function(){
      let a = {a:1, b:2};
      assert.deepEqual(a.filter(identity),{a:1,b:2});
      assert.deepEqual(filter(identity,a),{a:1,b:2});
    });
    it('should return only properties greaterThan(1)', function(){
      let a = {a:1, b:2};
      assert.deepEqual(a.filter(greaterThan(1)),{b:2});
      assert.deepEqual(filter(greaterThan(1),a),{b:2});
    });
    it('should return only properties greaterThan(0)', function(){
      let a = {a:1, b:2};
      assert.deepEqual(a.filter(greaterThan(0)),{a:1,b:2});
      assert.deepEqual(filter(greaterThan(0),a),{a:1,b:2});
    });
    it('should return empty object if no match', function(){
      let a = {a:1, b:2};
      assert.deepEqual(a.filter(greaterThan(5)),{});
      assert.deepEqual(filter(greaterThan(5),a),{});
    });
  });
});