zippa/lib/test/testWalk.js

A Generic Zipper Library

'use strict';

var _chai = require('chai');

var _chai2 = _interopRequireDefault(_chai);

var _sinonChai = require('sinon-chai');

var _sinonChai2 = _interopRequireDefault(_sinonChai);

var _index = require('../index');

var _tree_zipper = require('./tree_zipper');

var _utils = require('./utils');

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

_chai2.default.use(_sinonChai2.default);
var expect = _chai2.default.expect;


var log = function log(node) {
    console.log('LOG NODE:', node.data);
    return node;
};

describe('TreeZipper walk', function () {
    function getTree() {
        return new _tree_zipper.Node(1, [new _tree_zipper.Node(2, [new _tree_zipper.Node(4), new _tree_zipper.Node(5)]), new _tree_zipper.Node(3)]);
    }

    function incrementNode(node) {
        return new _tree_zipper.Node(node.data + 1, node.children);
    }

    it('postwalk works', function () {
        var z = _tree_zipper.TreeZipper.from(getTree());

        var initialNumbers = (0, _utils.collect)(function (node) {
            return node.data;
        }, z);

        expect(initialNumbers).to.deep.equal([1, 2, 4, 5, 3]);

        // Do the incrementation.
        z = (0, _index.postWalk)(incrementNode, z);

        // Check result.
        var afterNumbers = (0, _utils.collect)(function (node) {
            return node.data;
        }, z);
        expect(afterNumbers).to.deep.equal([2, 3, 5, 6, 4]);
    });

    it('prewalk is in correct order', function () {
        var z = _tree_zipper.TreeZipper.from(getTree());

        function _gatherNumbers(listRef, node) {
            listRef.push(node.data);
            return node;
        }
        var treeNumbers = [];
        var gatherNumbers = _gatherNumbers.bind(null, treeNumbers);
        z = (0, _index.preWalk)(gatherNumbers, z);

        expect(treeNumbers).to.deep.equal([1, 2, 4, 5, 3]);
    });
});