Chore: Add safety check in util.replaceHeader() (#610)

box · Jan 30, 2018 · 3a47c2e · 3a47c2e
1 parent 217fbce
commit 3a47c2e
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Showing 2 changed files with 21 additions and 7 deletions.
diff --git a/src/lib/PreviewUI.js b/src/lib/PreviewUI.js
@@ -341,14 +341,18 @@ class PreviewUI {
      * @return {void}
      */
     replaceHeader(replacementHeader) {
+        const headerToShow = this.container.querySelector(replacementHeader);
+        if (!headerToShow) {
+            return;
+        }
+
         // First hide all possible headers
         const headers = this.container.querySelectorAll(`.${CLASS_BOX_PREVIEW_HEADER}`);
         [].forEach.call(headers, (header) => {
             header.classList.add(CLASS_HIDDEN);
         });
 
         // Show the specified header
-        const headerToShow = this.container.querySelector(replacementHeader);
         headerToShow.classList.remove(CLASS_HIDDEN);
     }
 

diff --git a/src/lib/__tests__/PreviewUI-test.js b/src/lib/__tests__/PreviewUI-test.js
@@ -267,19 +267,29 @@ describe('lib/PreviewUI', () => {
 
 
     describe('replaceHeader()', () => {
-        it('should hide all headers and then show the specified header', () => {
+        const newHeader = document.createElement('div');
+
+        beforeEach(() => {
             containerEl = ui.setup(options);
-            const newHeader = document.createElement('div');
             newHeader.className = 'bp-header bp-draw-header bp-is-hidden';
-
             containerEl.appendChild(newHeader);
+        });
 
-            ui.replaceHeader('.bp-draw-header');
+        it('should do nothing if no valid header is specified', () => {
+            ui.replaceHeader('.bp-invalid-header');
 
-            expect(newHeader.classList.contains('bp-is-hidden')).to.be.false;
+            const baseHeader = containerEl.querySelector('.bp-base-header');
+            expect(newHeader).to.have.class('bp-is-hidden');
+            expect(baseHeader).to.not.have.class('bp-is-hidden');
+
+        });
+
+        it('should hide all headers and then show the specified header', () => {
+            ui.replaceHeader('.bp-draw-header');
 
             const baseHeader = containerEl.querySelector('.bp-base-header');
-            expect(baseHeader.classList.contains('bp-is-hidden')).to.be.true;
+            expect(newHeader).to.not.have.class('bp-is-hidden');
+            expect(baseHeader).to.have.class('bp-is-hidden');
 
         });
     });