Extract `GitHelpers` from System Test Cases

The majority of the test helpers declared in the ApplicationSystemTestCase are focused on git operations.

In an effort to prevent the ApplicationSystemTestCase from growing unchecked, this commit extracts the GitHelpers, then calls Module.include in to mix the helpers back into the parent class.

test/application_system_test_case.rb

diff --git a/test/application_system_test_case.rb b/test/application_system_test_case.rb
index c73caa8..a90ca46 100644
--- a/test/application_system_test_case.rb
+++ b/test/application_system_test_case.rb
@@ -1,74 +1,22 @@
 require "test_helper"
-require "middleman/rack"
-require "pathname"
-require "tmpdir"
 
 require_relative "../helpers/url_helpers"
+require "git_helpers"
 
 class ApplicationSystemTestCase < ActiveSupport::TestCase
   include Capybara::DSL
   include Capybara::Minitest::Assertions
   include UrlHelpers
+  include GitHelpers
 
   def around(&block)
-    directory = Dir.mktmpdir
-    begin
-      @repository = Git.init(directory)
-      block.call
-    ensure
-      FileUtils.rm_rf(directory)
-    end
+    with_git_directory(&block)
   end
 
   def expand_history
     find("summary", text: "Expand History").click
   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_built_output(&block)
-    git_directory = Pathname(@repository.dir.path)
-    build_directory = git_directory.join("build")
-
-    system <<~BASH, exception: true
-      bin/git-read \
-        --verbose \
-        --git-dir #{git_directory} \
-        --output-dir #{build_directory}
-    BASH
-
-    Capybara.app = Rack::Builder.new do
-      use Rack::Static,
-        urls: [""],
-        root: build_directory,
-        index: "index.html"
-
-      run -> (*) {}
-    end
-
-    block.call
-  end
-
-  def with_git_repository(&block)
-    ClimateControl.modify(GIT_DIR: @repository.dir.path) do
-      Capybara.app = Middleman.server
-
-      block.call Pathname(@repository.dir.path)
-    end
-  end
-
-  def expand_history
-    find("details > summary", text: "Expand History").click
-  end
-
   teardown do
     Capybara.reset_sessions!
     Capybara.use_default_driver

test/git_helpers.rb

diff --git a/test/git_helpers.rb b/test/git_helpers.rb
new file mode 100644
index 0000000..0cff2c7
--- /dev/null
+++ b/test/git_helpers.rb
@@ -0,0 +1,54 @@
+require "middleman/rack"
+require "pathname"
+require "tmpdir"
+
+module GitHelpers
+  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_built_output(&block)
+    git_directory = Pathname(@repository.dir.path)
+    build_directory = git_directory.join("build")
+
+    system <<~BASH, exception: true
+    bin/git-read \
+      --verbose \
+      --git-dir #{git_directory} \
+      --output-dir #{build_directory}
+    BASH
+
+    Capybara.app = Rack::Builder.new do
+      use Rack::Static,
+        urls: [""],
+        root: build_directory,
+        index: "index.html"
+
+      run -> (*) {}
+    end
+
+    block.call
+  end
+
+  def with_git_repository(&block)
+    ClimateControl.modify(GIT_DIR: @repository.dir.path) do
+      Capybara.app = Middleman.server
+
+      block.call Pathname(@repository.dir.path)
+    end
+  end
+
+  def with_git_directory(&block)
+    directory = Dir.mktmpdir
+    @repository = Git.init(directory)
+    block.call
+  ensure
+    FileUtils.rm_rf(directory)
+  end
+end

Extract GitHelpers from System Test Cases

Extract `GitHelpers` from System Test Cases