Extract `ApplicationSystemTestCase`

In preparation for an additional System Test, this commit extracts the test harness’ set-up and tear-down code into a super-class that the test case inherits from.

To simplify require path resolution, and enable calling require "application_system_test_case" instead of require_relative "./application_system_test_case", the test runner will need to append the "test" directory onto the $LOAD_PATH.

To do so, declare a Rakefile that contains a Rake::TestTask. Passing -W0 as “warning, level 0” is necessary, since our dependency on Middleman results in too much output noise without silencing Ruby warnings.

To run the full test suite, execute:

rake test

Rakefile

diff --git a/Rakefile b/Rakefile
new file mode 100644
index 0000000..be924a1
--- /dev/null
+++ b/Rakefile
@@ -0,0 +1,10 @@
+require "rake/testtask"
+
+Rake::TestTask.new do |test|
+  test.libs << "test"
+  test.pattern = "test/**/*_test.rb"
+  test.verbose = true
+  test.ruby_opts = ["-W0"]
+end
+
+task default: :test

test/application_system_test_case.rb

diff --git a/test/application_system_test_case.rb b/test/application_system_test_case.rb
new file mode 100644
index 0000000..dd46a69
--- /dev/null
+++ b/test/application_system_test_case.rb
@@ -0,0 +1,51 @@
+require "bundler"
+
+Bundler.require(:default, :test)
+
+ENV["MODE"] ||= "build"
+
+require "minitest/autorun"
+require "middleman/rack"
+require "active_support"
+require "active_support/test_case"
+require "pathname"
+require "tmpdir"
+
+
+class ApplicationSystemTestCase < ActiveSupport::TestCase
+  include Capybara::DSL
+  include Capybara::Minitest::Assertions
+
+  def around(&block)
+    directory = Dir.mktmpdir
+    begin
+      @repository = Git.init(directory)
+      block.call
+    ensure
+      FileUtils.rm_rf(directory)
+    end
+  end
+
+  def stage_file(filename, contents)
+    Pathname(@repository.dir.path).join(filename).write(contents)
+
+    @repository.add(filename)
+  end
+
+  def commit(message)
+    @repository.commit(message)
+  end
+
+  def with_git_repository(&block)
+    ClimateControl.modify(GIT_DIR: @repository.dir.path) do
+      Capybara.app = Middleman.server
+
+      block.call
+    end
+  end
+
+  teardown do
+    Capybara.reset_sessions!
+    Capybara.use_default_driver
+  end
+end

test/system/visitor_views_readme_test.rb

diff --git a/test/system/visitor_views_readme_test.rb b/test/system/visitor_views_readme_test.rb
index 4778e4c..a38ba2f 100644
--- a/test/system/visitor_views_readme_test.rb
+++ b/test/system/visitor_views_readme_test.rb
@@ -1,54 +1,6 @@
-require "bundler"
-
-Bundler.require(:default, :test)
-
-ENV["MODE"] ||= "build"
-
-require "minitest/autorun"
-require "middleman/rack"
-require "active_support"
-require "active_support/test_case"
-require "pathname"
-require "tmpdir"
-
-
-class VisitorViewsReadmeTest < ActiveSupport::TestCase
-  include Capybara::DSL
-  include Capybara::Minitest::Assertions
-
-  def around(&block)
-    directory = Dir.mktmpdir
-    begin
-      @repository = Git.init(directory)
-      block.call
-    ensure
-      FileUtils.rm_rf(directory)
-    end
-  end
-
-  def stage_file(filename, contents)
-    Pathname(@repository.dir.path).join(filename).write(contents)
-
-    @repository.add(filename)
-  end
-
-  def commit(message)
-    @repository.commit(message)
-  end
-
-  def with_git_repository(&block)
-    ClimateControl.modify(GIT_DIR: @repository.dir.path) do
-      Capybara.app = Middleman.server
-
-      block.call
-    end
-  end
-
-  teardown do
-    Capybara.reset_sessions!
-    Capybara.use_default_driver
-  end
+require "application_system_test_case"
 
+class VisitorViewsReadmeTest < ApplicationSystemTestCase
   test "visitor views README" do
     stage_file("README.md", <<~MARKDOWN)
     git-read

Extract ApplicationSystemTestCase

Extract `ApplicationSystemTestCase`