Ensures resolved issue #1665 - Added RSpec test to ensure LDAP attributes get reset if no value is provided from remote.

spec/lib/sequencer/unit/import/ldap/user/mapping_spec.rb

@@ -0,0 +1,27 @@
+require 'rails_helper'
+
+RSpec.describe Sequencer::Unit::Import::Ldap::User::Mapping, sequencer: :unit do
+
+  it 'ensures to unset attribute value if none is provided' do
+
+    ldap_config = {
+      user_attributes: {
+        firstName:      'firstname',
+        lastName:       'lastname',
+        samaccountname: 'login',
+      }
+    }
+
+    resource = {
+      samaccountname: 'Some41',
+      firstName:      'Some',
+    }
+
+    provided = process(
+      ldap_config: ldap_config,
+      resource:    resource,
+    )
+
+    expect(provided['lastname']).to be_nil
+  end
+end