node-red/test/nodes/core/storage/28-tail_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 path = require('path');
var fs = require('fs-extra');
var mkdirp = require('mkdirp');

var tailNode = require("../../../../nodes/core/storage/28-tail.js");
var helper = require("../../helper.js");

describe('TailNode', function() {

    var resourcesDir = path.join(__dirname,"..","..","..","resources");
    var fileToTail = path.join(resourcesDir,"28-tail-test-file.txt");
    fs.writeFile(fileToTail, "Tail message line 1\nTail message line 2\n", function (err) {
        if (err) { console.log('cannot write to '+fileToTail); }
    });

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

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

    it('should be loaded', function(done) {
        var flow = [{id:"tailNode1", type:"tail", name: "tailNode", "split":true, "filename":fileToTail}];
        helper.load(tailNode, flow, function() {
            var tailNode1 = helper.getNode("tailNode1");
            tailNode1.should.have.property('name', 'tailNode');
            done();
        });
    });

    it('tail should tail a file', function(done) {
        var flow = [{id:"tailNode1", type:"tail", name: "tailNode", "split":true, "filename":fileToTail, "wires":[["helperNode1"]]},
                    {id:"helperNode1", type:"helper", wires:[]}];
        helper.load(tailNode, flow, function() {
            var tailNode1 = helper.getNode("tailNode1");
            var helperNode1 = helper.getNode("helperNode1");
            var inputCounter = 0;
            helperNode1.on("input", function(msg) {
                //console.log(msg);
                msg.should.have.property('topic', fileToTail);
                msg.payload.should.equal("Tail message line " + (++inputCounter + 2));
                if (inputCounter === 2) {
                    done();
                }
            });
            fs.appendFileSync(fileToTail, "Tail message line 3\nTail message line 4\n");
        });
    });

    it('tail should work in non-split mode', function(done) {
        var flow = [{id:"tailNode1", type:"tail", name: "tailNode", "split":false, "filename":fileToTail, "wires":[["helperNode1"]]},
                    {id:"helperNode1", type:"helper", wires:[]}];
        helper.load(tailNode, flow, function() {
            var tailNode1 = helper.getNode("tailNode1");
            var helperNode1 = helper.getNode("helperNode1");
            helperNode1.on("input", function(msg) {
                //console.log(msg);
                msg.should.have.property('topic', fileToTail);
                msg.payload.should.equal("Tail message line 5\nTail message line 6\n");
                done();
            });
            fs.appendFile(fileToTail, "Tail message line 5\nTail message line 6\n");
        });
    });

    it('tail should handle file going away and coming back', function(done) {
        var flow = [{id:"tailNode1", type:"tail", name: "tailNode", "split":true, "filename":fileToTail, "wires":[["helperNode1"]]},
                    {id:"helperNode1", type:"helper", wires:[]}];
        helper.load(tailNode, flow, function() {
            var tailNode1 = helper.getNode("tailNode1");
            var helperNode1 = helper.getNode("helperNode1");
            var inputCounter = 0;
            var warned = false;
            tailNode1.on("log", function(msg) {
                if (msg.level == "warn") { warned = true; }
                if ((inputCounter === 3)&&(warned === true)) { done(); }
            });
            helperNode1.on("input", function(msg) {
                msg.should.have.property('topic', fileToTail);
                msg.payload.should.equal("Tail message line A");
                inputCounter += 1;
                if ((inputCounter === 3)&&(warned === true)) { done(); }
            });
            fs.writeFileSync(fileToTail, "Tail message line A\n");
            setTimeout( function() {
                fs.appendFileSync(fileToTail, "Tail message line A\n");
                fs.appendFileSync(fileToTail, "Tail message line A\n");
            },250);
        });
    });

});