Add API post /users/approve for Admin

app/services/users/approve_service.rb

@@ -7,8 +7,9 @@ module Users
     end
 
     def execute(user)
-      return error(_('You are not allowed to approve a user')) unless allowed?
-      return error(_('The user you are trying to approve is not pending an approval')) unless approval_required?(user)
+      return error(_('You are not allowed to approve a user'), :forbidden) unless allowed?
+      return error(_('The user you are trying to approve is not pending an approval'), :conflict) if user.active?
+      return error(_('The user you are trying to approve is not pending an approval'), :conflict) unless approval_required?(user)
 
       if user.activate
         # Resends confirmation email if the user isn't confirmed yet.
@@ -18,9 +19,9 @@ module Users
         DeviseMailer.user_admin_approval(user).deliver_later
 
         after_approve_hook(user)
-        success
+        success(message: 'Success', http_status: :created)
       else
-        error(user.errors.full_messages.uniq.join('. '))
+        error(user.errors.full_messages.uniq.join('. '), :unprocessable_entity)
       end
     end
 

changelogs/unreleased/263107-user-admin-approval-approve-user-via-api.yml

+---
+title: Add API endoint for Administrators to approve pending users
+merge_request: 47564
+author:
+type: added

doc/api/users.md

@@ -1275,8 +1275,8 @@ Parameters:
 Returns:
 
 - `201 OK` on success.
-- `404 User Not Found` if user cannot be found.
-- `403 Forbidden` when trying to activate a user blocked by admin or by LDAP synchronization.
+- `404 User Not Found` if the user cannot be found.
+- `403 Forbidden` if the user cannot be activated because they are blocked by an administrator or by LDAP synchronization.
 
 ### Get user contribution events
 
@@ -1337,6 +1337,44 @@ Example response:
 ]
 ```
 
+## Approve user
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/263107) in GitLab 13.7.
+
+Approves the specified user. Available only for administrators.
+
+```plaintext
+POST /users/:id/approve
+```
+
+Parameters:
+
+- `id` (required) - ID of specified user
+
+```shell
+curl --request POST --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/users/42/approve"
+```
+
+Returns:
+
+- `201 OK` on success.
+- `404 User Not Found` if user cannot be found.
+- `403 Forbidden` if the user cannot be approved because they are blocked by an administrator or by LDAP synchronization.
+
+Example Responses:
+
+```json
+{ "message": "Success" }
+```
+
+```json
+{ "message": "404 User Not Found" }
+```
+
+```json
+{ "message": "The user you are trying to approve is not pending an approval" }
+```
+
 ## Get an impersonation token of a user
 
 > Requires admin permissions.

lib/api/users.rb

@@ -534,6 +534,24 @@ module API
 
         user.activate
       end
+
+      desc 'Approve a pending user. Available only for admins.'
+      params do
+        requires :id, type: Integer, desc: 'The ID of the user'
+      end
+      post ':id/approve', feature_category: :authentication_and_authorization do
+        user = User.find_by(id: params[:id])
+        not_found!('User') unless can?(current_user, :read_user, user)
+
+        result = ::Users::ApproveService.new(current_user).execute(user)
+
+        if result[:success]
+          result
+        else
+          render_api_error!(result[:message], result[:http_status])
+        end
+      end
+
       # rubocop: enable CodeReuse/ActiveRecord
       desc 'Deactivate an active user. Available only for admins.'
       params do

spec/factories/users.rb

@@ -35,6 +35,10 @@ FactoryBot.define do
       user_type { :alert_bot }
     end
 
+    trait :deactivated do
+      after(:build) { |user, _| user.deactivate! }
+    end
+
     trait :project_bot do
       user_type { :project_bot }
     end

spec/requests/api/users_spec.rb

@@ -2510,6 +2510,98 @@ RSpec.describe API::Users, :do_not_mock_admin_mode do
     end
   end
 
+  context 'approve pending user' do
+    shared_examples '404' do
+      it 'returns 404' do
+        expect(response).to have_gitlab_http_status(:not_found)
+        expect(json_response['message']).to eq('404 User Not Found')
+      end
+    end
+
+    describe 'POST /users/:id/approve' do
+      subject(:approve) { post api("/users/#{user_id}/approve", api_user) }
+
+      let_it_be(:pending_user) { create(:user, :blocked_pending_approval) }
+      let_it_be(:deactivated_user) { create(:user, :deactivated) }
+      let_it_be(:blocked_user) { create(:user, :blocked) }
+
+      context 'performed by a non-admin user' do
+        let(:api_user) { user }
+        let(:user_id) { pending_user.id }
+
+        it 'is not authorized to perform the action' do
+          expect { approve }.not_to change { pending_user.reload.state }
+          expect(response).to have_gitlab_http_status(:forbidden)
+          expect(json_response['message']).to eq('You are not allowed to approve a user')
+        end
+      end
+
+      context 'performed by an admin user' do
+        let(:api_user) { admin }
+
+        context 'for a deactivated user' do
+          let(:user_id) { deactivated_user.id }
+
+          it 'does not approve a deactivated user' do
+            expect { approve }.not_to change { deactivated_user.reload.state }
+            expect(response).to have_gitlab_http_status(:conflict)
+            expect(json_response['message']).to eq('The user you are trying to approve is not pending an approval')
+          end
+        end
+
+        context 'for an pending approval user' do
+          let(:user_id) { pending_user.id }
+
+          it 'returns 201' do
+            expect { approve }.to change { pending_user.reload.state }.to('active')
+            expect(response).to have_gitlab_http_status(:created)
+            expect(json_response['message']).to eq('Success')
+          end
+        end
+
+        context 'for an active user' do
+          let(:user_id) { user.id }
+
+          it 'returns 201' do
+            expect { approve }.not_to change { user.reload.state }
+            expect(response).to have_gitlab_http_status(:conflict)
+            expect(json_response['message']).to eq('The user you are trying to approve is not pending an approval')
+          end
+        end
+
+        context 'for a blocked user' do
+          let(:user_id) { blocked_user.id }
+
+          it 'returns 403' do
+            expect { approve }.not_to change { blocked_user.reload.state }
+            expect(response).to have_gitlab_http_status(:conflict)
+            expect(json_response['message']).to eq('The user you are trying to approve is not pending an approval')
+          end
+        end
+
+        context 'for a ldap blocked user' do
+          let(:user_id) { ldap_blocked_user.id }
+
+          it 'returns 403' do
+            expect { approve }.not_to change { ldap_blocked_user.reload.state }
+            expect(response).to have_gitlab_http_status(:conflict)
+            expect(json_response['message']).to eq('The user you are trying to approve is not pending an approval')
+          end
+        end
+
+        context 'for a user that does not exist' do
+          let(:user_id) { non_existing_record_id }
+
+          before do
+            approve
+          end
+
+          it_behaves_like '404'
+        end
+      end
+    end
+  end
+
   describe 'POST /users/:id/block' do
     let(:blocked_user) { create(:user, state: 'blocked') }