Add regression tests to Cucumber.

features/rendering.feature

@@ -5,6 +5,13 @@ Feature: Rendering
   But I want to make it as simply as possible
   So render with Liquid and place in Layouts
 
+  Scenario: When receiving bad Liquid
+    Given I have a "index.html" page with layout "simple" that contains "{% include invalid.html %}"
+    And   I have a simple layout that contains "{{ content }}"
+    When  I run jekyll build
+    Then  I should get a non-zero exit-status
+    And   I should see "Liquid Exception" in the build output
+
   Scenario: Render Liquid and place in layout
     Given I have a "index.html" page with layout "simple" that contains "Hi there, Jekyll {{ jekyll.environment }}!"
     And I have a simple layout that contains "{{ content }}Ahoy, indeed!"

features/step_definitions/jekyll_steps.rb

@@ -24,6 +24,7 @@ end
 After do
   FileUtils.rm_rf(TEST_DIR)   if File.exist?(TEST_DIR)
   FileUtils.rm(JEKYLL_COMMAND_OUTPUT_FILE) if File.exist?(JEKYLL_COMMAND_OUTPUT_FILE)
+  FileUtils.rm(JEKYLL_COMMAND_STATUS_FILE) if File.exist?(JEKYLL_COMMAND_STATUS_FILE)
   Dir.chdir(File.dirname(TEST_DIR))
 end
 
@@ -227,3 +228,7 @@ end
 Then /^I should see "(.*)" in the build output$/ do |text|
   assert_match Regexp.new(text), jekyll_run_output
 end
+
+Then /^I should get a non-zero exit(?:\-| )status$/ do
+  assert jekyll_run_status > 0
+end

features/support/env.rb

@@ -16,6 +16,7 @@ JEKYLL_SOURCE_DIR = File.dirname(File.dirname(File.dirname(__FILE__)))
 TEST_DIR    = File.expand_path(File.join('..', '..', 'tmp', 'jekyll'), File.dirname(__FILE__))
 JEKYLL_PATH = File.expand_path(File.join(File.dirname(__FILE__), '..', '..', 'bin', 'jekyll'))
 JEKYLL_COMMAND_OUTPUT_FILE = File.join(File.dirname(TEST_DIR), 'jekyll_output.txt')
+JEKYLL_COMMAND_STATUS_FILE = File.join(File.dirname(TEST_DIR), 'jekyll_status.txt')
 
 def source_dir(*files)
   File.join(TEST_DIR, *files)
@@ -36,12 +37,20 @@ def jekyll_output_file
   JEKYLL_COMMAND_OUTPUT_FILE
 end
 
+def jekyll_status_file
+  JEKYLL_COMMAND_STATUS_FILE
+end
+
 def jekyll_run_output
   File.read(jekyll_output_file) if File.file?(jekyll_output_file)
 end
 
+def jekyll_run_status
+  (File.read(jekyll_status_file) rescue 0).to_i
+end
+
 def run_bundle(args)
-  child = run_in_shell('bundle', *args.strip.split(' '))
+  run_in_shell('bundle', *args.strip.split(' '))
 end
 
 def run_jekyll(args)
@@ -49,8 +58,21 @@ def run_jekyll(args)
   child.status.exitstatus == 0
 end
 
+# -----------------------------------------------------------------------------
+# XXX: POSIX::Spawn::Child does not write output when the exit status is > 0
+#        for example when doing [:out, :err] => [file, "w"] it will skip
+#        writing the file entirely, we sould switch to Open.
+# -----------------------------------------------------------------------------
+
 def run_in_shell(*args)
-  POSIX::Spawn::Child.new *args, :out => [JEKYLL_COMMAND_OUTPUT_FILE, "w"]
+  spawned = POSIX::Spawn::Child.new(*args)
+  status = spawned.status.exitstatus
+  File.write(JEKYLL_COMMAND_STATUS_FILE, status)
+  File.open(JEKYLL_COMMAND_OUTPUT_FILE, "w+") do |file|
+    status == 0 ? file.write(spawned.out) : file.write(spawned.err)
+  end
+
+  spawned
 end
 
 def slug(title)