Added forked projects API call function

Part of https://gitlab.com/gitlab-org/gitlab-ce/issues/58583

app/assets/javascripts/api.js

@@ -12,6 +12,7 @@ const Api = {
   groupProjectsPath: '/api/:version/groups/:id/projects.json',
   projectsPath: '/api/:version/projects.json',
   projectPath: '/api/:version/projects/:id',
+  forkedProjectsPath: '/api/:version/projects/:id/forks',
   projectLabelsPath: '/:namespace_path/:project_path/-/labels',
   projectMergeRequestsPath: '/api/:version/projects/:id/merge_requests',
   projectMergeRequestPath: '/api/:version/projects/:id/merge_requests/:mrid',
@@ -113,6 +114,21 @@ const Api = {
     return axios.get(url);
   },
 
+  /**
+   * Get all projects for a forked relationship to a specified project
+   * @param {string} projectPath - Path or ID of a project
+   * @param {Object} params - Get request parameters
+   * @returns {Promise} - Request promise
+   */
+  projectForks(projectPath, params) {
+    const url = Api.buildUrl(Api.forkedProjectsPath).replace(
+      ':id',
+      encodeURIComponent(projectPath),
+    );
+
+    return axios.get(url, { params });
+  },
+
   /**
    * Get all Merge Requests for a project, eventually filtering based on
    * supplied parameters

spec/frontend/api_spec.js

@@ -474,4 +474,27 @@ describe('Api', () => {
         .catch(done.fail);
     });
   });
+
+  describe('projectForks', () => {
+    it('gets forked projects', done => {
+      const dummyProjectPath = 'gitlab-org/gitlab-ce';
+      const expectedUrl = `${dummyUrlRoot}/api/${dummyApiVersion}/projects/${encodeURIComponent(
+        dummyProjectPath,
+      )}/forks`;
+
+      jest.spyOn(axios, 'get');
+
+      mock.onGet(expectedUrl).replyOnce(200, ['fork']);
+
+      Api.projectForks(dummyProjectPath, { visibility: 'private' })
+        .then(({ data }) => {
+          expect(data).toEqual(['fork']);
+          expect(axios.get).toHaveBeenCalledWith(expectedUrl, {
+            params: { visibility: 'private' },
+          });
+        })
+        .then(done)
+        .catch(done.fail);
+    });
+  });
 });