Maintenance: Error message about existing user with same email address is not expressive.

app/controllers/users_controller.rb

@@ -141,8 +141,8 @@ class UsersController < ApplicationController
       end
 
       # check if user already exists
-      exists = User.find_by(email: clean_params[:email].downcase.strip)
-      raise Exceptions::UnprocessableEntity, 'Email address is already used for other user.' if exists
+      exists = User.exists?(email: clean_params[:email].downcase.strip)
+      raise Exceptions::UnprocessableEntity, "Email address '#{clean_params[:email].downcase.strip}' is already used for other user." if exists
 
       user = User.new(clean_params)
       user.associations_from_param(params)

app/models/user.rb

@@ -1026,9 +1026,9 @@ try to find correct name
     return true if email.blank?
     return true if !changes
     return true if !changes['email']
-    return true if !User.find_by(email: email.downcase.strip)
+    return true if !User.exists?(email: email.downcase.strip)
 
-    raise Exceptions::UnprocessableEntity, 'Email address is already used for other user.'
+    raise Exceptions::UnprocessableEntity, "Email address '#{email.downcase.strip}' is already used for other user."
   end
 
   def validate_roles(role)

spec/requests/user_spec.rb

@@ -115,7 +115,7 @@ RSpec.describe 'User', type: :request, searchindex: true do
       post '/api/v1/users', params: params, headers: headers, as: :json
       expect(response).to have_http_status(:unprocessable_entity)
       expect(json_response['error']).to be_truthy
-      expect(json_response['error']).to eq('Email address is already used for other user.')
+      expect(json_response['error']).to eq("Email address 'rest-customer1@example.com' is already used for other user.")
 
       # email missing with enabled feature
       params = { firstname: 'some firstname', signup: true }
@@ -295,7 +295,7 @@ RSpec.describe 'User', type: :request, searchindex: true do
       post '/api/v1/users', params: params, as: :json
       expect(response).to have_http_status(:unprocessable_entity)
       expect(json_response).to be_truthy
-      expect(json_response['error']).to eq('Email address is already used for other user.')
+      expect(json_response['error']).to eq("Email address 'new_agent_by_admin2@example.com' is already used for other user.")
 
       # missing required attributes
       params = { note: 'some note' }