Gracefully handle null annotations

mzabriskie · mzabriskie · commit fd69512fd0c6 · 2016-07-15T10:38:22.000-06:00
closes instructure#7
diff --git a/src/a11y/renderScreenReaderHints.js b/src/a11y/renderScreenReaderHints.js
@@ -10,6 +10,8 @@ initEventHandlers();
  * @param {Array} annotations The annotations that hints are inserted for
  */
 export default function renderScreenReaderHints(annotations) {
+  annotations = Array.isArray(annotations) ? annotations : [];
+
   // Insert hints for each type
   Object.keys(SORT_TYPES).forEach((type) => {
     let sortBy = SORT_TYPES[type];
diff --git a/test/a11y/renderScreenReaderHints.spec.js b/test/a11y/renderScreenReaderHints.spec.js
@@ -32,6 +32,30 @@ describe('a11y::renderScreenReaderHints', function () {
   });
 
   describe('render', function () {
+    it('should render without annotations', function () {
+      let error;
+
+      try {
+        renderScreenReaderHints();
+      } catch (e) {
+        error = e;
+      }
+
+      equal(typeof error, 'undefined');
+    });
+
+    it('should render with non-array annotations', function () {
+      let error;
+
+      try {
+        renderScreenReaderHints(null);
+      } catch (e) {
+        error = e;
+      }
+
+      equal(typeof error, 'undefined');
+    });
+
     it('should render highlight', function () {
       renderScreenReaderHints([{
         type: 'highlight',
