Remove Api.approverUsers to use projectUsers

Api.approverUsers uses a legacy endpoint `/autocomplete/users`.
In effort to reduce gap between CE and EE and to phase out old APIs,
we're replacing approverUsers with a new /api/v4 endpoint.

Requires https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/31801
to be merged before merging in EE.

ee/app/assets/javascripts/api.js

@@ -8,25 +8,6 @@ export default {
   subscriptionPath: '/api/:version/namespaces/:id/gitlab_subscription',
   childEpicPath: '/api/:version/groups/:id/epics/:epic_iid/epics',
 
-  approverUsers(search, options, callback = () => {}) {
-    const url = Api.buildUrl('/autocomplete/users.json');
-    return axios
-      .get(url, {
-        params: Object.assign(
-          {
-            search,
-            per_page: 20,
-          },
-          options,
-        ),
-      })
-      .then(({ data }) => {
-        callback(data);
-
-        return data;
-      });
-  },
-
   userSubscription(namespaceId) {
     const url = Api.buildUrl(this.subscriptionPath).replace(':id', encodeURIComponent(namespaceId));
 

ee/app/assets/javascripts/approvals/components/approvers_select.vue

@@ -136,9 +136,8 @@ export default {
       });
     },
     fetchUsers(term) {
-      return Api.approverUsers(term, {
+      return Api.projectUsers(this.projectId, term, {
         skip_users: this.skipUserIds,
-        project_id: this.projectId,
       });
     },
     onChange() {

ee/spec/javascripts/approvals/components/approvers_select_spec.js

@@ -74,7 +74,7 @@ describe('Approvals ApproversSelect', () => {
   beforeEach(() => {
     jasmine.clock().install();
     spyOn(Api, 'groups').and.returnValue(Promise.resolve(TEST_GROUPS));
-    spyOn(Api, 'approverUsers').and.returnValue(Promise.resolve(TEST_USERS));
+    spyOn(Api, 'projectUsers').and.returnValue(Promise.resolve(TEST_USERS));
   });
 
   afterEach(() => {
@@ -127,9 +127,8 @@ describe('Approvals ApproversSelect', () => {
     });
 
     it('fetches users', () => {
-      expect(Api.approverUsers).toHaveBeenCalledWith(term, {
+      expect(Api.projectUsers).toHaveBeenCalledWith(TEST_PROJECT_ID, term, {
         skip_users: [],
-        project_id: TEST_PROJECT_ID,
       });
     });
   });
@@ -161,9 +160,8 @@ describe('Approvals ApproversSelect', () => {
     });
 
     it('skips users', () => {
-      expect(Api.approverUsers).toHaveBeenCalledWith('', {
+      expect(Api.projectUsers).toHaveBeenCalledWith(TEST_PROJECT_ID, '', {
         skip_users: skipUserIds,
-        project_id: TEST_PROJECT_ID,
       });
     });
   });