1 files changed, 29 insertions, 4 deletions
diff --git a/railties/test/commands/server_test.rb b/railties/test/commands/server_test.rb
index 33715ea75f..c84be439e4 100644
--- a/railties/test/commands/server_test.rb
+++ b/railties/test/commands/server_test.rb
@@ -1,15 +1,15 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require "isolation/abstract_unit"
 require "env_helpers"
 require "rails/command"
 require "rails/commands/server/server_command"
 
-class Rails::ServerTest < ActiveSupport::TestCase
+class Rails::Command::ServerCommandTest < ActiveSupport::TestCase
   include EnvHelpers
 
   def test_environment_with_server_option
-    args = ["thin", "-e", "production"]
+    args = ["-u", "thin", "-e", "production"]
     options = parse_arguments(args)
     assert_equal "production", options[:environment]
     assert_equal "thin", options[:server]
@@ -22,6 +22,24 @@ class Rails::ServerTest < ActiveSupport::TestCase
     assert_nil options[:server]
   end
 
+  def test_explicit_using_option
+    args = ["-u", "thin"]
+    options = parse_arguments(args)
+    assert_equal "thin", options[:server]
+  end
+
+  def test_using_server_mistype
+    assert_match(/Could not find server "tin". Maybe you meant "thin" or "cgi"/, run_command("--using", "tin"))
+  end
+
+  def test_using_positional_argument_deprecation
+    assert_match(/DEPRECATION WARNING/, run_command("tin"))
+  end
+
+  def test_using_known_server_that_isnt_in_the_gemfile
+    assert_match(/Could not load server "unicorn". Maybe you need to the add it to the Gemfile/, run_command("-u", "unicorn"))
+  end
+
   def test_daemon_with_option
     args = ["-d"]
     options = parse_arguments(args)
@@ -35,7 +53,7 @@ class Rails::ServerTest < ActiveSupport::TestCase
   end
 
   def test_server_option_without_environment
-    args = ["thin"]
+    args = ["-u", "thin"]
     with_rack_env nil do
       with_rails_env nil do
         options = parse_arguments(args)
@@ -222,6 +240,13 @@ class Rails::ServerTest < ActiveSupport::TestCase
   end
 
   private
+    def run_command(*args)
+      build_app
+      rails "server", *args
+    ensure
+      teardown_app
+    end
+
     def parse_arguments(args = [])
       Rails::Command::ServerCommand.new([], args).server_options
     end