Extracted nickname registration out of the UsersController and into its

own service.

app/controllers/users_controller.rb

@@ -119,77 +119,17 @@ class UsersController < ApplicationController
     # The special case where someone is changing the case of their own username
     return render_available_true if changing_case_of_own_username(target_user, username)
 
-    validator = UsernameValidator.new(username)
-    if !validator.valid_format?
-      render json: {errors: validator.errors}
-    elsif !SiteSetting.call_discourse_hub?
-      check_username_locally(username)
-    else
-      check_username_with_hub_server(target_user, username)
-    end
+    checker = UsernameCheckerService.new
+    email = params[:email] || target_user.try(:email)
+    render(json: checker.check_username(username, email))
   rescue RestClient::Forbidden
     render json: {errors: [I18n.t("discourse_hub.access_token_problem")]}
   end
 
-  def check_username_locally(username)
-    if User.username_available?(username)
-      render_available_true
-    else
-      render_unavailable_with_suggestion(UserNameSuggester.suggest(username))
-    end
-  end
-
   def user_from_params_or_current_user
     params[:for_user_id] ? User.find(params[:for_user_id]) : current_user
   end
 
-  def available_globally_and_suggestion_from_hub(target_user, username, email_given)
-    if email_given
-      global_match, available, suggestion =
-        DiscourseHub.nickname_match?(username, params[:email] || target_user.email)
-      { available_globally:            available || global_match,
-        suggestion_from_discourse_hub: suggestion,
-        global_match:                  global_match }
-    else
-      args = DiscourseHub.nickname_available?(username)
-      { available_globally:            args[0],
-        suggestion_from_discourse_hub: args[1],
-        global_match:                  false }
-    end
-  end
-
-  # Contact the Discourse Hub server
-  def check_username_with_hub_server(target_user, username)
-    email_given                   = (params[:email].present? || target_user.present?)
-    available_locally             = User.username_available?(username)
-    info                          = available_globally_and_suggestion_from_hub(target_user, username, email_given)
-    available_globally            = info[:available_globally]
-    suggestion_from_discourse_hub = info[:suggestion_from_discourse_hub]
-    global_match                  = info[:global_match]
-    if available_globally && available_locally
-      render json: { available: true, global_match: (global_match ? true : false) }
-    elsif available_locally && !available_globally
-      if email_given
-        # Nickname and email do not match what's registered on the discourse hub.
-        render json: { available: false, global_match: false, suggestion: suggestion_from_discourse_hub }
-      else
-        # The nickname is available locally, but is registered on the discourse hub.
-        # We need an email to see if the nickname belongs to this person.
-        # Don't give a suggestion until we get the email and try to match it with on the discourse hub.
-        render json: { available: false }
-      end
-    elsif available_globally && !available_locally
-      # Already registered on this site with the matching nickname and email address. Why are you signing up again?
-      render json: { available: false, suggestion: UserNameSuggester.suggest(username) }
-    else
-      # Not available anywhere.
-      render_unavailable_with_suggestion(suggestion_from_discourse_hub)
-    end
-  end
-
-  def render_unavailable_with_suggestion(suggestion)
-    render json: { available: false, suggestion: suggestion }
-  end
 
   def create
     return fake_success_response if suspicious? params

app/services/username_checker_service.rb

@@ -0,0 +1,69 @@
+class UsernameCheckerService
+
+  def check_username(username, email)
+    validator = UsernameValidator.new(username)
+    if !validator.valid_format?
+      {errors: validator.errors}
+    elsif !SiteSetting.call_discourse_hub?
+      check_username_locally(username)
+    else
+      check_username_with_hub_server(username, email)
+    end
+
+  end
+
+  # Contact the Discourse Hub server
+  def check_username_with_hub_server(username, email)
+    available_locally             = User.username_available?(username)
+    info                          = available_globally_and_suggestion_from_hub(username, email)
+    available_globally            = info[:available_globally]
+    suggestion_from_discourse_hub = info[:suggestion_from_discourse_hub]
+    global_match                  = info[:global_match]
+    if available_globally && available_locally
+      { available: true, global_match: (global_match ? true : false) }
+    elsif available_locally && !available_globally
+      if email.present?
+        # Nickname and email do not match what's registered on the discourse hub.
+        { available: false, global_match: false, suggestion: suggestion_from_discourse_hub }
+      else
+        # The nickname is available locally, but is registered on the discourse hub.
+        # We need an email to see if the nickname belongs to this person.
+        # Don't give a suggestion until we get the email and try to match it with on the discourse hub.
+        { available: false }
+      end
+    elsif available_globally && !available_locally
+      # Already registered on this site with the matching nickname and email address. Why are you signing up again?
+      { available: false, suggestion: UserNameSuggester.suggest(username) }
+    else
+      # Not available anywhere.
+      render_unavailable_with_suggestion(suggestion_from_discourse_hub)
+    end
+  end
+
+  def render_unavailable_with_suggestion(suggestion)
+    { available: false, suggestion: suggestion }
+  end
+
+  def check_username_locally(username)
+    if User.username_available?(username)
+      { available: true }
+    else
+      { available: false, suggestion: UserNameSuggester.suggest(username) }
+    end
+  end
+
+  def available_globally_and_suggestion_from_hub(username, email)
+    if email.present?
+      global_match, available, suggestion =
+        DiscourseHub.nickname_match?(username, email)
+      { available_globally:            available || global_match,
+        suggestion_from_discourse_hub: suggestion,
+        global_match:                  global_match }
+    else
+      args = DiscourseHub.nickname_available?(username)
+      { available_globally:            args[0],
+        suggestion_from_discourse_hub: args[1],
+        global_match:                  false }
+    end
+  end
+end

spec/services/username_checker_service_spec.rb

@@ -0,0 +1,104 @@
+require 'spec_helper'
+
+describe UsernameCheckerService do
+
+  describe 'check_username' do
+
+    before do
+      @service = UsernameCheckerService.new
+      @nil_email = nil
+      @email = 'vincentvega@example.com'
+    end
+
+    context 'Username invalid' do
+      it 'rejects blank usernames' do
+        result = @service.check_username('',  @nil_email)
+        expect(result).to have_key(:errors)
+      end
+      it 'rejects too short usernames' do
+        result = @service.check_username('a', @nil_email)
+        expect(result).to have_key(:errors)
+      end
+      it 'rejects too long usernames' do
+        result = @service.check_username('a123456789b123456789c123456789', @nil_email)
+        expect(result).to have_key(:errors)
+      end
+
+      it 'rejects usernames with invalid characters' do
+        result = @service.check_username('vincent-', @nil_email)
+        expect(result).to have_key(:errors)
+      end
+
+      it 'rejects usernames that do not start with an alphanumeric character' do
+        result = @service.check_username('_vincent', @nil_email)
+        expect(result).to have_key(:errors)
+      end
+    end
+
+    context 'Using Discourse Hub' do
+      before do
+        SiteSetting.stubs(:call_discourse_hub?).returns(true)
+      end
+
+      context 'and email is given' do
+        it 'username is available locally but not globally' do
+          DiscourseHub.stubs(:nickname_available?).returns([false, 'suggestion'])
+          DiscourseHub.stubs(:nickname_match?).returns([true, false, nil])
+          result = @service.check_username('vincent', @email)
+          expected = { available: true, global_match: true }
+          expect(result).to eq(expected)
+        end
+
+      end
+
+      it 'username is available both locally and globally' do
+        DiscourseHub.stubs(:nickname_available?).returns([true, nil])
+        DiscourseHub.stubs(:nickname_match?).returns([false, true, nil])
+        result = @service.check_username('vincent', @email)
+        expected = { available: true, global_match: false }
+        expect(result).to eq(expected)
+      end
+
+      it 'username is available locally but not globally' do
+        DiscourseHub.stubs(:nickname_match?).returns([false, true, nil])
+        result = @service.check_username('vincent', @email)
+        expected = { available: true, global_match: false }
+        expect(result).to eq(expected)
+      end
+
+      it 'username is available globally but not locally' do
+        DiscourseHub.stubs(:nickname_match?).returns([false, true, nil])
+        User.stubs(:username_available?).returns(false)
+        UserNameSuggester.stubs(:suggest).returns('einar-j')
+        expected = { available: false, suggestion: 'einar-j' }
+        result = @service.check_username('vincent', @email)
+        expect(result).to eq(expected)
+      end
+
+      it 'username not available anywhere' do
+        DiscourseHub.stubs(:nickname_match?).returns([false, false, 'suggestion'])
+        expected = { available: false, suggestion: 'suggestion', global_match: false }
+        @nil_email = nil
+        result = @service.check_username('vincent', @email)
+        expect(result).to eq(expected)
+      end
+    end
+
+    context 'Discourse Hub disabled' do
+      it 'username not available locally' do
+        User.stubs(:username_available?).returns(false)
+        UserNameSuggester.stubs(:suggest).returns('einar-j')
+        result = @service.check_username('vincent', @nil_email)
+        result[:available].should be_false
+        result[:suggestion].should eq('einar-j')
+      end
+
+      it 'username available locally' do
+        User.stubs(:username_available?).returns(true)
+        result = @service.check_username('vincent', @nil_email)
+        result[:available].should be_true
+      end
+    end
+  end
+
+end