UX: Add validator for SiteSetting#sso_overrides_email.

spec/components/validators/sso_overrides_email_validator_spec.rb

@@ -0,0 +1,71 @@
+require 'rails_helper'
+
+RSpec.describe SsoOverridesEmailValidator do
+  subject { described_class.new }
+
+  describe '#valid_value?' do
+    describe "when 'email editable' is true" do
+      before do
+        SiteSetting.enable_sso = true
+        SiteSetting.email_editable = true
+      end
+
+      describe 'when val is false' do
+        it 'should be valid' do
+          expect(subject.valid_value?('f')).to eq(true)
+        end
+      end
+
+      describe 'when value is true' do
+        it 'should not be valid' do
+          expect(subject.valid_value?('t')).to eq(false)
+
+          expect(subject.error_message).to eq(I18n.t(
+            'site_settings.errors.email_editable_enabled'
+          ))
+        end
+      end
+    end
+
+    describe "when 'email editable' is false" do
+      before do
+        SiteSetting.enable_sso = true
+        SiteSetting.email_editable = false
+      end
+
+      describe 'when value is false' do
+        it 'should be valid' do
+          expect(subject.valid_value?('f')).to eq(true)
+        end
+      end
+
+      describe 'when value is true' do
+        it 'should be valid' do
+          expect(subject.valid_value?('t')).to eq(true)
+        end
+      end
+    end
+
+    describe "when 'enable sso' is false" do
+      before do
+        SiteSetting.enable_sso = false
+      end
+
+      describe 'when value is false' do
+        it 'should be valid' do
+          expect(subject.valid_value?('f')).to eq(true)
+        end
+      end
+
+      describe 'when value is true' do
+        it 'should not be valid' do
+          expect(subject.valid_value?('t')).to eq(false)
+
+          expect(subject.error_message).to eq(I18n.t(
+            'site_settings.errors.enable_sso_disabled'
+          ))
+        end
+      end
+    end
+  end
+end