Support TAP output for CI

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## Master
 
+## v190 (7/24/2018)
+
+* Support TAP output for Heroku CI (https://github.com/heroku/heroku-buildpack-ruby/pull/790).
+
 ## v189 (7/10/2018)
 
 * Colorize build failures and warnings. (https://github.com/heroku/heroku-buildpack-ruby/pull/788)

bin/support/ruby_test

@@ -21,7 +21,12 @@ def execute_test(command)
 end
 
 def execute_command(command)
-  pipe(command, :user_env => true)
+  # Normally the `pipe` command will indent output so that it
+  # matches the build output, however in a test TAP depends on
+  # having no whitespace before output. To avoid adding whitespace
+  # for the original Kernel.puts to be used by passing in the
+  # Kernel object.
+  pipe(command, :user_env => true, :output_object => Kernel)
 end
 
 # $ bin/test BUILD_DIR ENV_DIR ARTIFACT_DIR

lib/language_pack/shell_helpers.rb

@@ -216,11 +216,13 @@ def wait_with_timeout
     def pipe(command, options = {})
       output = options[:buffer] || ""
       silent = options[:silent]
+      # self.puts uses the method defined in this file
+      output_object = options[:output_object] || self
       IO.popen(command_options_to_string(command, options)) do |io|
         until io.eof?
           buffer = io.gets
           output << buffer
-          puts buffer unless silent
+          output_object.puts(buffer) unless silent
         end
       end
 

lib/language_pack/version.rb

@@ -3,6 +3,6 @@
 # This file is automatically generated by rake
 module LanguagePack
   class LanguagePack::Base
-    BUILDPACK_VERSION = "v189"
+    BUILDPACK_VERSION = "v190"
   end
 end

spec/hatchet/ci_spec.rb

@@ -27,7 +27,9 @@
 
   it "Works with a vanilla ruby app" do
     Hatchet::Runner.new("ruby_no_rails_test").run_ci do |test_run|
-      # Expect success test run
+      # Test no whitespace in front of output
+      expect(test_run.output).to_not match(/^ +Finished in/)
+      expect(test_run.output).to     match(/^Finished in/)
     end
   end