fix to prevent errors from being thrown if elements are not present and (#7)

tests

Author: tscanlin

README.md

@@ -178,6 +178,12 @@ tocbot.refresh()
 ## Changelog
 
 
+### v2.1.2
+
+#### Fixed
+- [patch] prevent errors from being thrown when elements are not present and add tests.
+
+
 ### v2.1.1
 
 #### Changed

package.json

@@ -1,6 +1,6 @@
 {
   "name": "tocbot",
-  "version": "2.1.1",
+  "version": "2.1.2",
   "description": "Generate a table of contents based on the heading structure of a html document.",
   "main": "src/js/index.js",
   "scripts": {

src/js/build-html.js

@@ -45,6 +45,11 @@ module.exports = function(options) {
 
     var parent = document.querySelector(selector);
 
+    // Return if no parent is found.
+    if (parent === null) {
+      return;
+    }
+
     // Remove existing child if it exists.
     if (parent.firstChild) {
       parent.removeChild(parent.firstChild);

src/js/index.js

@@ -138,8 +138,12 @@
     // Destroy it if it exists first.
     tocbot.destroy();
 
-    // Get headings array
+    // Get headings array.
     headingsArray = parseContent.selectHeadings(options.contentSelector, options.headingSelector);
+    // Return if no headings are found.
+    if (headingsArray === null) {
+      return;
+    }
 
     // Build nested headings array.
     var nestedHeadingsObj = parseContent.nestHeadingsArray(headingsArray);

src/js/parse-content.js

@@ -92,6 +92,7 @@ module.exports = function parseContent(options) {
         .querySelectorAll(selectors);
     } catch (e) {
       console.warn('Element not found: ' + contentSelector); // eslint-disable-line
+      return null;
     }
   }
 

test/index.js

@@ -77,6 +77,22 @@ describe('Tocbot', function () {
       // The 4th event is added by smooth-scroll.
       expect(count).to.equal(4);
     });
+
+    it('should not throw an error if a content element isn\'t found', function () {
+      GLOBAL.window.tocbot.destroy();
+      expect(GLOBAL.window.tocbot.init).to.not.throw(Error);
+      GLOBAL.window.tocbot.init({
+        tocSelector: '.missing'
+      });
+    });
+
+    it('should not throw an error if a toc element isn\'t found', function () {
+      GLOBAL.window.tocbot.destroy();
+      expect(GLOBAL.window.tocbot.init).to.not.throw(Error);
+      GLOBAL.window.tocbot.init({
+        contentSelector: '.not-here'
+      });
+    });
   });
 
   describe('#destroy', function () {