test/application_system_test_case.rb

@@ -4,4 +4,15 @@ class ApplicationSystemTestCase < ActionDispatch::SystemTestCase
   driven_by :selenium,
     using: ENV["VISIBLE_SYSTEM_TESTS"].present? ? :chrome : :headless_chrome,
     screen_size: [ 1400, 1400 ]
+
+  def login(email, password = "secret")
+    visit new_session_url
+
+    fill_in "Email", with: email
+    fill_in "Password", with: "secret"
+
+    click_on "Create Session"
+
+    assert_text "Session was successfully created"
+  end
 end

test/system/sessions_test.rb

@@ -6,24 +6,13 @@ class SessionsTest < ApplicationSystemTestCase
   end
 
   test "should create session" do
-    visit new_session_url
-
-    fill_in "Email", with: @user.email
-    fill_in "Password", with: "secret"
-
-    click_on "Create Session"
+    login(@user.email)
 
     assert_text "Session was successfully created"
   end
 
   test "should destroy Session" do
-    visit new_session_url
-
-    fill_in "Email", with: @user.email
-    fill_in "Password", with: "secret"
-
-    click_on "Create Session"
-    assert_text "Session was successfully created"
+    login(@user.email)
 
     visit root_url
     click_on "Log out", match: :first