1 files changed, 37 insertions, 3 deletions
diff --git a/spec/frontend/diffs/utils/merge_request_spec.js b/spec/frontend/diffs/utils/merge_request_spec.js
index 8c7b1e1f2a5..c070e8c004d 100644
--- a/spec/frontend/diffs/utils/merge_request_spec.js
+++ b/spec/frontend/diffs/utils/merge_request_spec.js
@@ -2,30 +2,64 @@ import { getDerivedMergeRequestInformation } from '~/diffs/utils/merge_request';
 import { diffMetadata } from '../mock_data/diff_metadata';
 
 describe('Merge Request utilities', () => {
-  const derivedMrInfo = {
+  const derivedBaseInfo = {
     mrPath: '/gitlab-org/gitlab-test/-/merge_requests/4',
     userOrGroup: 'gitlab-org',
     project: 'gitlab-test',
     id: '4',
   };
+  const derivedVersionInfo = {
+    diffId: '4',
+    startSha: 'eb227b3e214624708c474bdab7bde7afc17cefcc',
+  };
+  const noVersion = {
+    diffId: undefined,
+    startSha: undefined,
+  };
   const unparseableEndpoint = {
     mrPath: undefined,
     userOrGroup: undefined,
     project: undefined,
     id: undefined,
+    ...noVersion,
   };
 
   describe('getDerivedMergeRequestInformation', () => {
-    const endpoint = `${diffMetadata.latest_version_path}.json?searchParam=irrelevant`;
+    let endpoint = `${diffMetadata.latest_version_path}.json?searchParam=irrelevant`;
 
     it.each`
       argument                   | response
-      ${{ endpoint }}            | ${derivedMrInfo}
+      ${{ endpoint }}            | ${{ ...derivedBaseInfo, ...noVersion }}
       ${{}}                      | ${unparseableEndpoint}
       ${{ endpoint: undefined }} | ${unparseableEndpoint}
       ${{ endpoint: null }}      | ${unparseableEndpoint}
     `('generates the correct derived results based on $argument', ({ argument, response }) => {
       expect(getDerivedMergeRequestInformation(argument)).toStrictEqual(response);
     });
+
+    describe('version information', () => {
+      const bare = diffMetadata.latest_version_path;
+      endpoint = diffMetadata.merge_request_diffs[0].compare_path;
+
+      it('still gets the correct derived information', () => {
+        expect(getDerivedMergeRequestInformation({ endpoint })).toMatchObject(derivedBaseInfo);
+      });
+
+      it.each`
+        url                                                   | versionPart
+        ${endpoint}                                           | ${derivedVersionInfo}
+        ${`${bare}?diff_id=${derivedVersionInfo.diffId}`}     | ${{ ...derivedVersionInfo, startSha: undefined }}
+        ${`${bare}?start_sha=${derivedVersionInfo.startSha}`} | ${{ ...derivedVersionInfo, diffId: undefined }}
+      `(
+        'generates the correct derived version information based on $url',
+        ({ url, versionPart }) => {
+          expect(getDerivedMergeRequestInformation({ endpoint: url })).toMatchObject(versionPart);
+        },
+      );
+
+      it('extracts nothing if there is no available version-like information in the URL', () => {
+        expect(getDerivedMergeRequestInformation({ endpoint: bare })).toMatchObject(noVersion);
+      });
+    });
   });
 });