Updates for 2.7.0 (#115)

* Updates for 2.7.0

* Remove 14.x from node-version

* Add unit tests for waitForIntersection and "Don't activate when preview parameter doesn't match a recipe ID"

.github/workflows/nodejs.yml

@@ -9,7 +9,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [14.x, 16.x, 18.x]
+        node-version: [16.x, 18.x]
 
     steps:
     - uses: actions/checkout@v1

lib/mojito.js

@@ -112,6 +112,11 @@ Mojito = (function () {
                     previewRecipe = this.options.recipes[recipeId],
                     success = false;
 
+                // Disable test when preview parameter exists but doesn't match a recipe ID
+                if (recipeId && !previewRecipe) {
+                    return false;
+                }
+
                 // If previewing, run recipe and return
                 if (previewRecipe != null) {
                     this.log('Forcing test [' + this.options.name + '][' + this.options.id + '] into recipe [' + previewRecipe.name + '][' + recipeId + ']');
@@ -724,6 +729,37 @@ Mojito = (function () {
                 domWatcher.observe(elements[i], watchOptions);
             }
         },
+        /**
+         * Run a callback when changes in the intersection of a target element with an ancestor element or with a top-level document's viewport
+         * @param element: dom element
+         * @param callback: callback function on change
+         * @param options: an optional object providing options plus an "once" option
+         *                 e.g. threshold, rootMargin, see https://developer.mozilla.org/en-US/docs/Web/API/IntersectionObserver
+         *                 once, run callback once or everytime the element is intersecting. default is true
+         */
+        waitForIntersection: function (element, callback, options) {
+            options = options||{ once: true };
+            if (!('once' in options)) {
+                options.once = true;
+            }
+
+            var observer = new IntersectionObserver(function (entries, observer) {
+                var entry = entries[0];
+                if (!entry) {
+                    return;
+                }
+
+                if (entry.isIntersecting) {
+                    callback(entry);
+
+                    if (options.once) {
+                        observer.disconnect();
+                    }
+                }
+            }, options);
+
+            observer.observe(element);
+        },
         /**
          * get user id (uuidv4)
          */