FEATURE: add setting auto_approve_email_domains to auto approve users (#9323)

* FEATURE: add setting `auto_approve_email_domains` to auto approve users

This commit adds a new site setting `auto_approve_email_domains` to
auto approve users based on their email address domain.

Note that if a domain already exists in `email_domains_whitelist` then
`auto_approve_email_domains` needs to be duplicated there as well,
since users won’t be able to register with email address that is
not allowed in `email_domains_whitelist`.

* Update config/locales/server.en.yml

Co-Authored-By: Robin Ward <robin.ward@gmail.com>

spec/requests/users_controller_spec.rb

@@ -583,7 +583,7 @@ describe UsersController do
       UsersController.any_instance.stubs(:honeypot_value).returns(nil)
       UsersController.any_instance.stubs(:challenge_value).returns(nil)
       SiteSetting.allow_new_registrations = true
-      @user = Fabricate.build(:user, password: "strongpassword")
+      @user = Fabricate.build(:user, email: "foobar@example.com", password: "strongpassword")
     end
 
     let(:post_user_params) do
@@ -826,6 +826,22 @@ describe UsersController do
           new_user = User.find(json["user_id"])
           expect(new_user.locale).not_to eq("fr")
         end
+
+        it "will auto approve user if the user email domain matches auto_approve_email_domains setting" do
+          Jobs.run_immediately!
+          SiteSetting.must_approve_users = true
+          SiteSetting.auto_approve_email_domains = "example.com"
+
+          post "/u.json", params: post_user_params.merge(active: true, api_key: api_key.key)
+
+          expect(response.status).to eq(200)
+          json = JSON.parse(response.body)
+
+          new_user = User.find(json["user_id"])
+          expect(json['active']).to be_truthy
+          expect(new_user.approved).to be_truthy
+          expect(ReviewableUser.pending.find_by(target: new_user)).to be_blank
+        end
       end
     end