1 files changed, 53 insertions, 0 deletions
diff --git a/spec/frontend/issuable/popover/index_spec.js b/spec/frontend/issuable/popover/index_spec.js
new file mode 100644
index 00000000000..b1aa7f0f0b0
--- /dev/null
+++ b/spec/frontend/issuable/popover/index_spec.js
@@ -0,0 +1,53 @@
+import { setHTMLFixture } from 'helpers/fixtures';
+import * as createDefaultClient from '~/lib/graphql';
+import initIssuablePopovers from '~/issuable/popover/index';
+
+createDefaultClient.default = jest.fn();
+
+describe('initIssuablePopovers', () => {
+  let mr1;
+  let mr2;
+  let mr3;
+  let issue1;
+
+  beforeEach(() => {
+    setHTMLFixture(`
+      <div id="one" class="gfm-merge_request" data-mr-title="title" data-iid="1" data-project-path="group/project" data-reference-type="merge_request">
+        MR1
+      </div>
+      <div id="two" class="gfm-merge_request" title="title" data-iid="1" data-project-path="group/project" data-reference-type="merge_request">
+        MR2
+      </div>
+      <div id="three" class="gfm-merge_request">
+        MR3
+      </div>
+      <div id="four" class="gfm-issue" title="title" data-iid="1" data-project-path="group/project" data-reference-type="issue">
+        MR3
+      </div>
+    `);
+
+    mr1 = document.querySelector('#one');
+    mr2 = document.querySelector('#two');
+    mr3 = document.querySelector('#three');
+    issue1 = document.querySelector('#four');
+
+    mr1.addEventListener = jest.fn();
+    mr2.addEventListener = jest.fn();
+    mr3.addEventListener = jest.fn();
+    issue1.addEventListener = jest.fn();
+  });
+
+  it('does not add the same event listener twice', () => {
+    initIssuablePopovers([mr1, mr1, mr2, issue1]);
+
+    expect(mr1.addEventListener).toHaveBeenCalledTimes(1);
+    expect(mr2.addEventListener).toHaveBeenCalledTimes(1);
+    expect(issue1.addEventListener).toHaveBeenCalledTimes(1);
+  });
+
+  it('does not add listener if it does not have the necessary data attributes', () => {
+    initIssuablePopovers([mr1, mr2, mr3]);
+
+    expect(mr3.addEventListener).not.toHaveBeenCalled();
+  });
+});