1 files changed, 48 insertions, 0 deletions
diff --git a/app/models/concerns/nullify_if_blank.rb b/app/models/concerns/nullify_if_blank.rb
new file mode 100644
index 00000000000..5a5cc51509b
--- /dev/null
+++ b/app/models/concerns/nullify_if_blank.rb
@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+# Helper that sets attributes to nil prior to validation if they
+# are blank (are false, empty or contain only whitespace), to avoid
+# unnecessarily persisting empty strings.
+#
+# Model usage:
+#
+#   class User < ApplicationRecord
+#     include NullifyIfBlank
+#
+#     nullify_if_blank :name, :email
+#   end
+#
+#
+# Test usage:
+#
+#   RSpec.describe User do
+#     it { is_expected.to nullify_if_blank(:name) }
+#     it { is_expected.to nullify_if_blank(:email) }
+#   end
+#
+module NullifyIfBlank
+  extend ActiveSupport::Concern
+
+  class_methods do
+    def nullify_if_blank(*attributes)
+      self.attributes_to_nullify += attributes
+    end
+  end
+
+  included do
+    class_attribute :attributes_to_nullify,
+      instance_accessor: false,
+      instance_predicate: false,
+      default: Set.new
+
+    before_validation :nullify_blank_attributes
+  end
+
+  private
+
+  def nullify_blank_attributes
+    self.class.attributes_to_nullify.each do |attribute|
+      assign_attributes(attribute => nil) if read_attribute(attribute).blank?
+    end
+  end
+end