feat: skip first load

separate event & boolean to turn off first load
filipedeschamps · Mar 18, 2020 · 3fd49fe · 3fd49fe
1 parent 81d4cfb
commit 3fd49fe
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Showing 3 changed files with 46 additions and 5 deletions.
diff --git a/src/FeedEmitter.js b/src/FeedEmitter.js
@@ -62,7 +62,7 @@ class FeedEmitter extends EventEmitter {
    * we create a new instance of this "Class".
    * @param {Object} [options={ userAgent: defaultUA }] [description]
    */
-  constructor(options = { userAgent: DEFAULT_UA }) {
+  constructor(options = { userAgent: DEFAULT_UA, skipFirstLoad: false }) {
     super();
 
     this.feedList = [];
@@ -74,6 +74,12 @@ class FeedEmitter extends EventEmitter {
      * @type {string}
      */
     this.userAgent = options.userAgent;
+
+    /**
+     * Whether or not to skip the normal emit event on first load
+     * @type {boolean}
+     */
+    this.skipFirstLoad = options.skipFirstLoad;
   }
 
 
@@ -182,7 +188,7 @@ class FeedEmitter extends EventEmitter {
    */
   createSetInterval(feed) {
     const feedManager = new FeedManager(this, feed);
-    feedManager.getContent();
+    feedManager.getContent(true);
     return setInterval(feedManager.getContent.bind(feedManager), feed.refresh);
   }
 

diff --git a/src/FeedManager.js b/src/FeedManager.js
@@ -38,19 +38,22 @@ class FeedManager {
    * Now that we have all the new items, add them to the
    feed item list.
    * @param  {Object} data data to mutate
+   * @param {boolean} firstload Whether or not this is the first laod
    */
-  populateNewItemsInFeed(data) {
+  populateNewItemsInFeed(data, firstload) {
     data.newItems.forEach((item) => {
       this.feed.addItem(item);
-      this.instance.emit(this.feed.eventName, item);
+      if (!(firstload && this.instance.skipFirstLoad)) {
+        this.instance.emit(this.feed.eventName, item);
+      }
     });
   }
 
   onError(error) {
     this.instance.emit('error', error);
   }
 
-  async getContent() {
+  async getContent(firstload) {
     this.feed.fetchData()
       .then((items) => {
         const data = {
@@ -61,6 +64,9 @@ class FeedManager {
         this.sortItemsByDate(data);
         this.identifyNewItems(data);
         this.populateNewItemsInFeed(data);
+        if (firstload && !this.instance.skipFirstLoad) {
+          this.instance.emit(`initial-load:${this.feed.url}`, { url: this.feed.url, items: this.feed.items });
+        }
       })
       .catch(this.onError.bind(this));
   }

diff --git a/test/unit/rss-feed-emitter.spec.js b/test/unit/rss-feed-emitter.spec.js
@@ -105,6 +105,33 @@ describe('RssFeedEmitter (unit)', () => {
     });
   });
 
+  describe('when instantiated with skipFirstLoad option', () => {
+    it('does not emit an initial load event', (done) => {
+      nock('https://www.nintendolife.com/')
+        .get('/feeds/latest')
+        .replyWithFile(200, path.join(__dirname, '/fixtures/nintendo-latest-first-fetch.xml'))
+        .get('/feeds/latest')
+        .replyWithFile(200, path.join(__dirname, '/fixtures/nintendo-latest-second-fetch.xml'));
+
+      feeder.destroy();
+      feeder = new RssFeedEmitter({ skipFirstLoad: true });
+
+      feeder.add({
+        url: 'https://www.nintendolife.com/feeds/latest',
+        refresh: 100,
+      });
+
+      feeder.on('initial-load:https://nintendolife.com/feeds/latest', () => {
+        expect(false).to.eq(true);
+      });
+      feeder.on('new-item', (item) => {
+        if (item.title === 'Nintendo Life Weekly: Huge Pokémon Reveal Next Month, Arguably the Rarest Nintendo Game, and More') {
+          done();
+        }
+      });
+    });
+  });
+
   describe('#add', () => {
     it('should be a Function', () => {
       expect(feeder.add).to.be.a('function');
@@ -204,6 +231,8 @@ describe('RssFeedEmitter (unit)', () => {
         .twice()
         .replyWithFile(200, path.join(__dirname, '/fixtures/nintendo-latest-first-fetch.xml'));
 
+      feeder = new RssFeedEmitter({ skipFirstLoad: true });
+
       feeder.add({
         url: 'https://www.nintendolife.com/feeds/latest',
         refresh: notDefaultRefresh1,