Apply reviewer suggestions

- Gather the de-duplication logic together

- DRY mock user data

app/assets/javascripts/vue_shared/components/user_select/user_select.vue

@@ -88,6 +88,8 @@ export default {
       },
     },
     searchUsers: {
+      // TODO Remove error policy
+      // https://gitlab.com/gitlab-org/gitlab/-/issues/329750
       errorPolicy: 'all',
       query: searchUsers,
       variables() {
@@ -98,15 +100,9 @@ export default {
         };
       },
       update(data) {
-        if (!data.workspace?.users?.nodes) return [];
-
-        // TODO this de-duplication is temporary (BE fix required)
-        // Also remove the error policy and related test (mockdata)
-        // https://gitlab.com/gitlab-org/gitlab/-/issues/327822
-        const users = data.workspace?.users?.nodes.filter((x) => x).map(({ user }) => user);
-        return users.reduce((acc, cur) => {
-          return acc.find((u) => u.id === cur.id) ? acc : [...acc, cur];
-        }, []);
+        // TODO Remove null filter (BE fix required)
+        // https://gitlab.com/gitlab-org/gitlab/-/issues/329750
+        return data.workspace?.users?.nodes.filter((x) => x).map(({ user }) => user) || [];
       },
       debounce: ASSIGNEES_DEBOUNCE_DELAY,
       error({ graphQLErrors }) {
@@ -140,15 +136,20 @@ export default {
       if (!this.participants) {
         return [];
       }
-      const mergedSearchResults = this.participants.reduce((acc, current) => {
-        if (
-          !acc.some((user) => current.username === user.username) &&
-          (current.name.includes(this.search) || current.username.includes(this.search))
-        ) {
-          acc.push(current);
-        }
-        return acc;
-      }, this.searchUsers);
+
+      const filteredParticipants = this.participants.filter(
+        (user) => user.name.includes(this.search) || user.username.includes(this.search),
+      );
+
+      // TODO this de-duplication is temporary (BE fix required)
+      // https://gitlab.com/gitlab-org/gitlab/-/issues/327822
+      const mergedSearchResults = filteredParticipants
+        .concat(this.searchUsers)
+        .reduce(
+          (acc, current) => (acc.some((user) => current.id === user.id) ? acc : [...acc, current]),
+          [],
+        );
+
       return this.moveCurrentUserToStart(mergedSearchResults);
     },
     isSearchEmpty() {

spec/frontend/sidebar/mock_data.js

@@ -366,6 +366,25 @@ export const subscriptionNullResponse = {
   },
 };
 
+const mockUser1 = {
+  id: 'gid://gitlab/User/1',
+  avatarUrl:
+    'https://www.gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=80\u0026d=identicon',
+  name: 'Administrator',
+  username: 'root',
+  webUrl: '/root',
+  status: null,
+};
+
+const mockUser2 = {
+  id: 'gid://gitlab/User/4',
+  avatarUrl: '/avatar2',
+  name: 'rookie',
+  username: 'rookie',
+  webUrl: 'rookie',
+  status: null,
+};
+
 export const searchResponse = {
   data: {
     workspace: {
@@ -373,24 +392,10 @@ export const searchResponse = {
       users: {
         nodes: [
           {
-            user: {
-              id: '1',
-              avatarUrl: '/avatar',
-              name: 'root',
-              username: 'root',
-              webUrl: 'root',
-              status: null,
-            },
+            user: mockUser1,
           },
           {
-            user: {
-              id: '2',
-              avatarUrl: '/avatar2',
-              name: 'rookie',
-              username: 'rookie',
-              webUrl: 'rookie',
-              status: null,
-            },
+            user: mockUser2,
           },
         ],
       },
@@ -407,39 +412,10 @@ export const projectMembersResponse = {
           // Remove nulls https://gitlab.com/gitlab-org/gitlab/-/issues/329750
           null,
           null,
-          {
-            user: {
-              id: 'gid://gitlab/User/1',
-              avatarUrl:
-                'https://www.gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=80\u0026d=identicon',
-              name: 'Administrator',
-              username: 'root',
-              webUrl: '/root',
-              status: null,
-            },
-          },
-          // This is a duplicated entry https://gitlab.com/gitlab-org/gitlab/-/issues/327822
-          {
-            user: {
-              id: 'gid://gitlab/User/1',
-              avatarUrl:
-                'https://www.gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=80\u0026d=identicon',
-              name: 'Administrator',
-              username: 'root',
-              webUrl: '/root',
-              status: null,
-            },
-          },
-          {
-            user: {
-              id: '2',
-              avatarUrl: '/avatar2',
-              name: 'rookie',
-              username: 'rookie',
-              webUrl: 'rookie',
-              status: null,
-            },
-          },
+          // Remove duplicated entry https://gitlab.com/gitlab-org/gitlab/-/issues/327822
+          mockUser1,
+          mockUser1,
+          mockUser2,
           {
             user: {
               id: 'gid://gitlab/User/2',
@@ -469,25 +445,9 @@ export const participantsQueryResponse = {
         iid: '1',
         participants: {
           nodes: [
-            {
-              id: 'gid://gitlab/User/1',
-              avatarUrl:
-                'https://www.gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=80\u0026d=identicon',
-              name: 'Administrator',
-              username: 'root',
-              webUrl: '/root',
-              status: null,
-            },
-            // this is a duplicated entry https://gitlab.com/gitlab-org/gitlab/-/issues/327822
-            {
-              id: 'gid://gitlab/User/1',
-              avatarUrl:
-                'https://www.gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=80\u0026d=identicon',
-              name: 'Administrator',
-              username: 'root',
-              webUrl: '/root',
-              status: null,
-            },
+            // Remove duplicated entry https://gitlab.com/gitlab-org/gitlab/-/issues/327822
+            mockUser1,
+            mockUser1,
             {
               id: 'gid://gitlab/User/2',
               avatarUrl: