Add contact disclosable attributes

Closes #992

test/models/contact/disclosable_test.rb

@@ -0,0 +1,39 @@
+require 'test_helper'
+
+class ContactDisclosableTest < ActiveSupport::TestCase
+  setup do
+    @contact = contacts(:john)
+    @original_disclosable_attributes = Contact.disclosable_attributes
+  end
+
+  teardown do
+    Contact.disclosable_attributes = @original_disclosable_attributes
+  end
+
+  def test_no_disclosed_attributes_by_default
+    assert_empty Contact.new.disclosed_attributes
+  end
+
+  def test_disclosable_attributes
+    assert_equal %w[name email], Contact.disclosable_attributes
+  end
+
+  def test_valid_without_disclosed_attributes
+    @contact.disclosed_attributes = []
+    assert @contact.valid?
+  end
+
+  def test_invalid_when_attribute_is_not_disclosable
+    Contact.disclosable_attributes = %w[some disclosable]
+    @contact.disclosed_attributes = %w[some undisclosable]
+
+    assert @contact.invalid?
+    assert_includes @contact.errors.get(:disclosed_attributes), 'contain unsupported attribute(s)'
+  end
+
+  def test_valid_when_attribute_is_disclosable
+    Contact.disclosable_attributes = %w[some disclosable]
+    @contact.disclosed_attributes = %w[disclosable]
+    assert @contact.valid?
+  end
+end