test sessions controller and fix style

spec/controllers/sessions_controller_spec.rb

@@ -0,0 +1,92 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+describe SessionsController, type: :controller do
+  before(:all) do
+    @user = create(:user, password: "example", password_confirmation: "example")
+  end
+
+  describe "GET #destroy" do
+    before(:each) do
+      @request.session[:user_id] = @user.id
+      get :destroy
+    end
+
+    it "should logout user" do
+      expect(@request.session[:user_id]).to be_nil
+    end
+
+    it "should redirect to root" do
+      expect(response).to redirect_to(root_path)
+    end
+  end
+
+  describe "POST #create" do
+    it "should login user in if credentials valid" do
+      post :create, params: {
+        session: {
+          email: @user.email,
+          password: "example",
+        },
+      }
+
+      expect(@request.session[:user_id]).to eql(@user.id)
+    end
+
+    it "should not login user in if credentials invalid" do
+      post :create, params: {
+        session: {
+          email: @user.email,
+          password: "invalid",
+        },
+      }
+
+      expect(@request.session[:user_id]).to be_nil
+    end
+  end
+
+  describe "GET/POST #omniauth" do
+    before(:all) do
+      OmniAuth.config.test_mode = true
+
+      OmniAuth.config.mock_auth[:twitter] = OmniAuth::AuthHash.new(
+        provider: "twitter",
+        uid: "twitter-user",
+        info: {
+          email: "user@twitter.com",
+          name: "Twitter User",
+          nickname: "username",
+          image: "example.png",
+        },
+      )
+
+      OmniAuth.config.on_failure = proc { |env|
+        OmniAuth::FailureEndpoint.new(env).redirect_to_failure
+      }
+    end
+
+    it "should create and login user with omniauth" do
+      request.env["omniauth.auth"] = OmniAuth.config.mock_auth[:twitter]
+      get :omniauth, params: { provider: :twitter }
+
+      u = User.last
+      expect(u.provider).to eql("twitter")
+      expect(u.email).to eql("user@twitter.com")
+      expect(@request.session[:user_id]).to eql(u.id)
+    end
+
+    it "should redirect to root on invalid omniauth login" do
+      request.env["omniauth.auth"] = :invalid_credentials
+      get :omniauth, params: { provider: :twitter }
+
+      expect(response).to redirect_to(root_path)
+    end
+
+    it "should not create session without omniauth env set" do
+      get :omniauth, params: { provider: 'google' }
+
+      expect(response).to redirect_to(root_path)
+    end
+  end
+end