fix(signatures): allow admins to manage inbox signatures without explicit membership (#260)

Administrators have access to all inboxes in an account but the
validate_inbox_access filter only checked InboxMember records, returning
401 for admins not explicitly added as inbox members.

app/controllers/api/v1/profile/inbox_signatures_controller.rb

@@ -48,8 +48,14 @@ class Api::V1::Profile::InboxSignaturesController < Api::BaseController
   end
 
   def validate_inbox_access
-    inbox_id = params[:inbox_id]
-    return if InboxMember.exists?(user_id: @user.id, inbox_id: inbox_id)
+    inbox = Inbox.find_by(id: params[:inbox_id])
+    return head :not_found unless inbox
+
+    account_user = @user.account_users.find_by(account_id: inbox.account_id)
+    return head :unauthorized unless account_user
+
+    return if account_user.administrator?
+    return if InboxMember.exists?(user_id: @user.id, inbox_id: inbox.id)
 
     head :unauthorized
   end

spec/controllers/api/v1/profile/inbox_signatures_controller_spec.rb

@@ -102,6 +102,23 @@ RSpec.describe 'Profile Inbox Signatures API', type: :request do
         expect(response).to have_http_status(:unauthorized)
       end
     end
+
+    context 'when the user is an administrator without inbox membership' do
+      let(:admin) { create(:user, account: account, role: :administrator) }
+
+      it 'returns the inbox signature' do
+        inbox_signature = create(:inbox_signature, user: admin, inbox: inbox)
+
+        get "/api/v1/profile/inbox_signatures/#{inbox.id}",
+            headers: admin.create_new_auth_token,
+            as: :json
+
+        expect(response).to have_http_status(:success)
+        json_response = response.parsed_body
+        expect(json_response['inbox_id']).to eq(inbox.id)
+        expect(json_response['message_signature']).to eq(inbox_signature.message_signature)
+      end
+    end
   end
 
   describe 'PUT /api/v1/profile/inbox_signatures/:inbox_id' do
@@ -164,6 +181,23 @@ RSpec.describe 'Profile Inbox Signatures API', type: :request do
       end
     end
 
+    context 'when the user is an administrator without inbox membership' do
+      let(:admin) { create(:user, account: account, role: :administrator) }
+
+      it 'creates a new inbox signature' do
+        expect do
+          put "/api/v1/profile/inbox_signatures/#{inbox.id}",
+              params: signature_params,
+              headers: admin.create_new_auth_token,
+              as: :json
+        end.to change(InboxSignature, :count).by(1)
+
+        expect(response).to have_http_status(:success)
+        json_response = response.parsed_body
+        expect(json_response['message_signature']).to eq('<p>Custom Signature</p>')
+      end
+    end
+
     context 'when params are invalid' do
       let(:invalid_params) do
         {
@@ -221,5 +255,21 @@ RSpec.describe 'Profile Inbox Signatures API', type: :request do
         expect(response).to have_http_status(:unauthorized)
       end
     end
+
+    context 'when the user is an administrator without inbox membership' do
+      let(:admin) { create(:user, account: account, role: :administrator) }
+
+      it 'deletes the inbox signature' do
+        create(:inbox_signature, user: admin, inbox: inbox)
+
+        expect do
+          delete "/api/v1/profile/inbox_signatures/#{inbox.id}",
+                 headers: admin.create_new_auth_token,
+                 as: :json
+        end.to change(InboxSignature, :count).by(-1)
+
+        expect(response).to have_http_status(:no_content)
+      end
+    end
   end
 end