Added unit tests for Fetcher

test/structs/unit_Fetcher.js

@@ -0,0 +1,197 @@
+/* eslint-env mocha */
+
+const chai = require('chai')
+const sinon = require('sinon')
+const expect = chai.expect
+const Feed = require('../../structs/Feed.js')
+const Schedule = require('../../structs/Schedule.js')
+const Fetcher = require('../../structs/Fetcher.js')
+
+describe('Unit::Fetcher', function () {
+  let dummySchedule
+  let dummyScheduleName
+  before(function () {
+    dummyScheduleName = 'foobar'
+    dummySchedule = { name: dummyScheduleName, addFeed: () => Promise.resolve(), addFeeds: () => Promise.resolve() }
+  })
+  describe('with no interval provided to constructor', function () {
+    it('should not initialize a default schedule to this.defaultSchedule', function () {
+      const fetcher = new Fetcher()
+      expect(fetcher.defaultSchedule).to.equal(undefined)
+    })
+  })
+
+  describe('with an interval provided to constructor', function () {
+    let fetcherWithInterval
+    before(function () {
+      fetcherWithInterval = new Fetcher(10)
+    })
+    after(function () {
+      clearInterval(fetcherWithInterval._intervals[0]) // Clear the interval so there's nothing left for the process to run
+    })
+    it('should initialize a default schedule to this.defaultSchedule as a Schedule', function () {
+      expect(fetcherWithInterval.defaultSchedule).to.be.instanceof(Schedule)
+    })
+    it('should populate .schedules', function () {
+      expect(fetcherWithInterval.schedules.length).to.equal(1)
+    })
+    it('should populate ._intervals', function () {
+      expect(fetcherWithInterval._intervals.length).to.equal(1)
+    })
+
+    describe('default schedule', function () {
+      it('emitting "article" should cause the fetcher to emit the same things', function () {
+        const spy = sinon.spy()
+        fetcherWithInterval.on('article', spy)
+        fetcherWithInterval.defaultSchedule.emit('article', 'foobar')
+        expect(spy.calledOnce).to.equal(true)
+        expect(spy.calledWithExactly('foobar')).to.equal(true)
+      })
+      it('emitting "err" should cause the fetcher to emit the same things', function () {
+        const spy = sinon.spy()
+        fetcherWithInterval.on('err', spy)
+        fetcherWithInterval.defaultSchedule.emit('err', 'foobar', 'jack')
+        expect(spy.calledOnce).to.equal(true)
+        expect(spy.calledWithExactly('foobar', 'jack')).to.equal(true)
+      })
+    })
+  })
+
+  describe('.addFeed', function () {
+    it('should return a Promise', function () {
+      const feed = new Feed('hfo')
+      const fetcher = new Fetcher()
+      fetcher.schedules[0] = dummySchedule
+      const prom = fetcher.addFeed(feed, dummyScheduleName)
+      expect(prom.then).to.be.a('function')
+      expect(prom.catch).to.be.a('function')
+    })
+    it('should reject when there are no schedules in .schedules array', function (done) {
+      const feed = new Feed('hfo')
+      const fetcher = new Fetcher()
+      fetcher.addFeed(feed, dummyScheduleName)
+        .then(() => done(new Error('Promise was resolved when schedules array was empty')))
+        .catch(() => done())
+    })
+    it('should reject when schedule name arg is not a string but fetcher.schedules is populated', function (done) {
+      const feed = new Feed('hfo')
+      const fetcher = new Fetcher()
+      fetcher.schedules.push(1)
+      fetcher.addFeed(feed, 123)
+        .then(() => done(new Error('Promise was resolved when schedules array was empty')))
+        .catch(err => {
+          if (err instanceof TypeError) done()
+          else done(new Error('Error was not an instance of TypeError'))
+        })
+    })
+    it('should reject when schedule name arg was not found in fetcher schedules', function (done) {
+      const feed = new Feed('hfo')
+      const fetcher = new Fetcher()
+      // Add some mock schedules
+      fetcher.defaultSchedule = { name: 'default', addFeed: () => Promise.resolve() }
+      fetcher.schedules.push(fetcher.defaultSchedule)
+      fetcher.addFeed(feed, 'dummdum')
+        .then(() => done(new Error('Promise was resolved when schedule name was not in schedules list of fetcher')))
+        .catch(() => done())
+    })
+    it('should add to this.defaultSchedule when no schedule name is passed in as an arg, if default schedule exists', async function () {
+      const feed = new Feed('hfo')
+      const fetcher = new Fetcher()
+      fetcher.defaultSchedule = { name: 'default', addFeed: () => Promise.resolve() }
+      fetcher.schedules.push(fetcher.defaultSchedule)
+      const spy = sinon.spy(fetcher.defaultSchedule, 'addFeed')
+      await fetcher.addFeed(feed)
+      expect(spy.calledOnce).to.equal(true)
+    })
+  })
+
+  describe('.addFeeds', function () {
+    it('should return a Promise', function () {
+      const feed = new Feed('adz')
+      const fetcher = new Fetcher()
+      fetcher.schedules[0] = dummySchedule
+      const prom = fetcher.addFeeds([feed], dummyScheduleName)
+      expect(prom.then).to.be.a('function')
+      expect(prom.catch).to.be.a('function')
+    })
+    it('should reject when there are no schedules in .schedules array', function (done) {
+      const feed = new Feed('hfo')
+      const fetcher = new Fetcher()
+      fetcher.addFeeds([feed], dummyScheduleName)
+        .then(() => done(new Error('Promise was resolved when schedules array was empty')))
+        .catch(() => done())
+    })
+    it('should reject when schedule name arg is not a string but fetcher.schedules is populated', function (done) {
+      const feed = new Feed('hfo')
+      const fetcher = new Fetcher()
+      fetcher.schedules.push(1)
+      fetcher.addFeeds([feed], 123)
+        .then(() => done(new Error('Promise was resolved when schedules array was empty')))
+        .catch(err => {
+          if (err instanceof TypeError) done()
+          else done(new Error('Error was not an instance of TypeError'))
+        })
+    })
+    it('should reject when schedule name arg was not found in fetcher schedules', function (done) {
+      const feed = new Feed('hfo')
+      const fetcher = new Fetcher()
+      // Add some mock schedules
+      fetcher.defaultSchedule = { name: 'default', addFeeds: () => Promise.resolve() }
+      fetcher.schedules.push(fetcher.defaultSchedule)
+      fetcher.addFeeds([feed], 'dummdum')
+        .then(() => done(new Error('Promise was resolved when schedule name was not in schedules list of fetcher')))
+        .catch(() => done())
+    })
+    it('should add to this.defaultSchedule when no schedule name is passed in as an arg, if default schedule exists', async function () {
+      const feed = new Feed('hfo')
+      const fetcher = new Fetcher()
+      fetcher.defaultSchedule = { name: 'default', addFeeds: () => Promise.resolve() }
+      fetcher.schedules.push(fetcher.defaultSchedule)
+      const spy = sinon.spy(fetcher.defaultSchedule, 'addFeeds')
+      await fetcher.addFeeds([feed])
+      expect(spy.calledOnce).to.equal(true)
+    })
+  })
+
+  describe('addSchedule', function () {
+    it('should throw a TypeError when arg is not a Schedule', function () {
+      const fetcher = new Fetcher()
+      expect(() => fetcher.addSchedule(123)).to.throw(TypeError)
+    })
+    it('should throw an error when schedule name already exists in fetcher.schedules', function () {
+      const fetcher = new Fetcher()
+      fetcher.addSchedule(new Schedule(1, 'abc'))
+      expect(() => fetcher.addSchedule(new Schedule(2, 'abc'))).to.throw(Error)
+      fetcher._intervals.forEach(interval => clearInterval(interval))
+    })
+    it('should populate fetcher.schedules and fetcher._intervals', function () {
+      const fetcher = new Fetcher()
+      fetcher.addSchedule(new Schedule(1, 'abc'))
+      expect(fetcher._intervals.length).to.equal(1)
+      expect(fetcher.schedules.length).to.equal(1)
+      fetcher._intervals.forEach(interval => clearInterval(interval))
+    })
+    it('should create an article listener for the schedule that then emits to the fetcher', function () {
+      const fetcher = new Fetcher()
+      const schedule = new Schedule(1, 'abc')
+      const spy = sinon.spy()
+      fetcher.addSchedule(schedule)
+      fetcher._intervals.forEach(interval => clearInterval(interval))
+      fetcher.on('article', spy)
+      schedule.emit('article', 'foobar')
+      expect(spy.calledOnce).to.equal(true)
+      expect(spy.calledWithExactly('foobar')).to.equal(true)
+    })
+    it('should create an err listener for the schedule that then emits to the fetcher', function () {
+      const fetcher = new Fetcher()
+      const schedule = new Schedule(1, 'abc')
+      const spy = sinon.spy()
+      fetcher.addSchedule(schedule)
+      fetcher._intervals.forEach(interval => clearInterval(interval))
+      fetcher.on('err', spy)
+      schedule.emit('err', 'foobar', 'foobar2')
+      expect(spy.calledOnce).to.equal(true)
+      expect(spy.calledWithExactly('foobar', 'foobar2')).to.equal(true)
+    })
+  })
+})