node-red-nodes/test/utility/exif/94-exif_spec.js

/**
 * Copyright 2014 IBM Corp.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 **/

var should = require("should");
var sinon = require('sinon');
var fs = require("fs");

var exifNode = require("../../../utility/exif/94-exif.js");

var helper = require('../../../../node-red/test/nodes/helper.js');

describe('exif node', function() {
    "use strict";

    beforeEach(function(done) {
        helper.startServer(done);
    });

    afterEach(function(done) {
        helper.unload();
        helper.stopServer(done);
    });

    it('extracts location data from Exif data of JPEG', function(done) {

        var exif = require('exif');
        var ExifImage = exif.ExifImage;

        // the jpg file is a single black dot but it was originally a photo taken at IBM Hursley
        var data = fs.readFileSync("./exif_test_image.jpg", null); // extracting genuine exif data to be fed back as the result of the stubbed ExifImage constructor

        var eD;

        new ExifImage({ image : data }, function (error, exifData) {
            if(error) {
                done(error);
            } else {
                eD = exifData;
            }

            var flow = [{id:"exifNode1", type:"exif", wires:[["helperNode1"]]},
                        {id:"helperNode1", type:"helper"}];

            helper.load(exifNode, flow, function() {
                var exifNode1 = helper.getNode("exifNode1");
                var helperNode1 = helper.getNode("helperNode1");

                helperNode1.on("input", function(msg) {
                    msg.location.lat.should.equal(50.95624); // this data is stored in the jpg file
                    msg.location.lon.should.equal(-1.36701);
                    done();
                });

                var stub = sinon.stub(ExifImage.prototype, 'loadImage', function(error, callback) {
                    stub.restore();
                    callback(null, eD);
                });

                exifNode1.receive({payload:data});
            });
        });

    });
});