coderwall · just3ws · Sep 22, 2014 · Sep 21, 2014
diff --git a/app/controllers/provider_user_lookups_controller.rb b/app/controllers/provider_user_lookups_controller.rb
@@ -0,0 +1,12 @@
+require Rails.root.join('app/services/provider_user_lookup_service')
+
+class ProviderUserLookupsController < ApplicationController
+  def show
+    service = Services::ProviderUserLookupService.new params[:provider], params[:username]
+    if user = service.lookup_user
+      redirect_to badge_path(user.username)
+    else
+      redirect_to root_path, flash: { notice: 'User not found' }
+    end
+  end
+end
diff --git a/app/services/provider_user_lookup_service.rb b/app/services/provider_user_lookup_service.rb
@@ -0,0 +1,26 @@
+module Services
+  class ProviderUserLookupService
+    def initialize(provider, username)
+      @provider = provider
+      @username = username
+    end
+
+    def lookup_user
+      if valid_provider? && valid_username?
+        User.where(@provider.to_sym => @username).first
+      else
+        nil
+      end
+    end
+
+    private
+
+    def valid_provider?
+      @provider.present? && [:twitter, :github, :linkedin].include?(@provider.to_sym)
+    end
+
+    def valid_username?
+      @username.present?
+    end
+  end
+end
diff --git a/config/routes.rb b/config/routes.rb
@@ -454,6 +454,8 @@
 
   get '/roll-the-dice' => 'users#randomize', as: :random_wall
 
+  get '/providers/:provider/:username' => 'provider_user_lookups#show'
+
 
   constraints ->(params, _) { params[:username] != 'admin' } do
     get '/:username' => 'users#show', as: :badge

diff --git a/spec/controllers/provider_user_lookups_controller_spec.rb b/spec/controllers/provider_user_lookups_controller_spec.rb
@@ -0,0 +1,34 @@
+require 'spec_helper'
+
+RSpec.describe ProviderUserLookupsController, :type => :controller do
+  let(:twitter_username) { 'birdy' }
+  let(:github_username) { 'birdy' }
+  let(:linked_in_username) { 'birdy' }
+  let(:attrs) do
+    {
+      twitter: twitter_username,
+      github: github_username,
+      linkedin: linked_in_username
+    }
+  end
+  let!(:user) {
+    Fabricate.create(:user, attrs)
+  }
+
+  describe 'GET /providers/:provider/:username' do
+    describe 'known user' do
+      it 'redirects to the current user for twitter' do
+        get :show, provider: 'twitter', username: twitter_username
+        expect(response).to redirect_to(badge_path(user.username))
+      end
+    end
+
+    describe 'unknown user' do
+      it 'redirects to the current user for twitter' do
+        get :show, provider: 'twitter', username: 'unknown'
+        expect(response).to redirect_to(root_path)
+        expect(flash[:notice]).to eql('User not found')
+      end
+    end
+  end
+end
diff --git a/spec/services/provider_user_lookup_service_spec.rb b/spec/services/provider_user_lookup_service_spec.rb
@@ -0,0 +1,38 @@
+require 'spec_helper'
+
+RSpec.describe Services::ProviderUserLookupService do
+  let(:twitter_username) { 'birdy' }
+  let!(:user) {
+    Fabricate.create(:user, twitter: twitter_username)
+  }
+
+  describe '#lookup_user' do
+    let(:provider) { 'twitter' }
+    let(:service) { Services::ProviderUserLookupService.new(provider, username) }
+
+    describe 'unknown provider' do
+      let(:provider) { 'unknown' }
+      let(:username) { 'unknown' }
+
+      it 'returns nil' do
+        expect(service.lookup_user).to be_nil
+      end
+    end
+
+    describe 'unknown user' do
+      let(:username) { 'unknown' }
+
+      it 'returns nil' do
+        expect(service.lookup_user).to be_nil
+      end
+    end
+
+    describe 'known provider and user' do
+      let(:username) { twitter_username }
+
+      it 'returns the user' do
+        expect(service.lookup_user).to eql(user)
+      end
+    end
+  end
+end