✅ pageIndex test; 🛠 return if bad element

Author: desandro

js/core.js

@@ -37,6 +37,7 @@ function InfiniteScroll( element, options ) {
 
   if ( !queryElem ) {
     console.error( 'Bad element for InfiniteScroll: ' + ( queryElem || element ) );
+    return;
   }
   element = queryElem;
   // do not initialize twice on same element

test/index.html

@@ -31,6 +31,7 @@
   <script src="unit/path.js"></script>
   <script src="unit/page-load.js"></script>
   <script src="unit/page-load-error.js"></script>
+  <script src="unit/page-index.js"></script>
   <script src="unit/check-last-page.js"></script>
   <script src="unit/prefill-window.js"></script>
   <script src="unit/prefill-element.js"></script>
@@ -66,6 +67,12 @@ <h2>page load error</h2>
       <div class="post">page 1, post 1</div>
     </div>
 
+    <h2>pageIndex</h2>
+    <div class="demo demo--page-index">
+      <div class="post">page 4, post 1</div>
+    </div>
+    <p><a class="page-index-next-link" href="page/5.html">Page 5</a></p>
+
     <h2>check last page</h2>
     <div class="demo demo--check-last-page">
       <div class="post">page 1, post 1</div>

test/unit/page-index.js

@@ -0,0 +1,29 @@
+QUnit.test( 'pageIndex', function( assert ) {
+
+  var demoElem = document.querySelector('.demo--page-index');
+
+  var infScroll = new InfiniteScroll( demoElem, {
+    path: '.page-index-next-link',
+    history: false,
+    scrollThreshold: false,
+  });
+
+  assert.equal( infScroll.pageIndex, 4, 'pageIndex from path element' );
+
+  infScroll.destroy();
+
+  // pageIndex from URL with {{#}} path
+  var prevURL = location.href;
+  // set URL with page number
+  history.replaceState( null, document.title, 'page/7' );
+  infScroll = new InfiniteScroll( demoElem, {
+    path: 'page/{{#}}',
+    history: false,
+    scrollThreshold: false,
+  });
+
+  assert.equal( infScroll.pageIndex, 7, 'pageIndex from URL with {{#}}' );
+
+  history.replaceState( null, document.title, prevURL );
+
+});