Handle buildpack not in a git repository

Glyn Normington · Glyn Normington · commit 511a968d14e6 · 2013-08-27T11:11:51.000+01:00
When the buildpack is not in a git repository, issue an appropriate
debug log message and prevent 'fatal' standard error messages from
appearing.

Improve test coverage of Buildpack class.

[#55742000]
diff --git a/lib/java_buildpack/buildpack.rb b/lib/java_buildpack/buildpack.rb
@@ -107,8 +107,6 @@ def release
 
     private
 
-    GIT_DIR = File.expand_path('../../.git', File.dirname(__FILE__)).freeze
-
     COMPONENTS_CONFIG = '../../config/components.yml'.freeze
 
     LIB_DIRECTORY = '.lib'
@@ -193,6 +191,10 @@ def self.framework_directory
       Pathname.new(File.expand_path('framework', File.dirname(__FILE__)))
     end
 
+    def self.git_dir
+      File.expand_path('../../.git', File.dirname(__FILE__))
+    end
+
     def self.jre_directory
       Pathname.new(File.expand_path('jre', File.dirname(__FILE__)))
     end
@@ -202,8 +204,12 @@ def self.log_git_data(logger)
       # Call the debug method passing a parameter rather than a block so that, should the git command
       # become inaccessible to the buildpack at some point in the future, we find out before someone
       # happens to switch on debug logging.
-      logger.debug("git remotes: #{`git --git-dir=#{GIT_DIR} remote -v`}")
-      logger.debug("git HEAD commit: #{`git --git-dir=#{GIT_DIR} log HEAD^!`}")
+      if system("git --git-dir=#{git_dir} status 2>/dev/null 1>/dev/null")
+       logger.debug("git remotes: #{`git --git-dir=#{git_dir} remote -v`}")
+       logger.debug("git HEAD commit: #{`git --git-dir=#{git_dir} log HEAD^!`}")
+      else
+        logger.debug('Buildpack is not stored in a git repository')
+      end
     end
 
     def self.lib_directory(app_dir)
diff --git a/spec/java_buildpack/buildpack_spec.rb b/spec/java_buildpack/buildpack_spec.rb
@@ -33,7 +33,7 @@ module JavaBuildpack
 
     before do
       YAML.stub(:load_file).with(File.expand_path('config/logging.yml')).and_return(
-          'default_log_level' => 'INFO'
+          'default_log_level' => 'DEBUG'
       )
       YAML.stub(:load_file).with(File.expand_path('config/components.yml')).and_return(
           'containers' => ['Test::StubContainer1', 'Test::StubContainer2'],
@@ -49,6 +49,8 @@ module JavaBuildpack
 
       Test::StubJre1.stub(:new).and_return(stub_jre1)
       Test::StubJre2.stub(:new).and_return(stub_jre2)
+
+      $stderr = StringIO.new
     end
 
     it 'should raise an error if more than one container can run an application' do
@@ -125,6 +127,26 @@ module JavaBuildpack
       with_buildpack { |buildpack| buildpack.detect }
     end
 
+    it 'logs information about the git repository of a buildpack' do
+      with_buildpack { |buildpack| buildpack.detect }
+      standard_error = $stderr.string
+      expect(standard_error).to match(/git remotes/)
+      expect(standard_error).to match(/git HEAD commit/)
+    end
+
+    it 'realises when buildpack is not stored in a git repository' do
+      Dir.mktmpdir do |tmp_dir|
+        Buildpack.stub(:git_dir).and_return(tmp_dir)
+        with_buildpack { |buildpack| buildpack.detect }
+        expect($stderr.string).to match(/Buildpack is not stored in a git repository/)
+      end
+    end
+
+    it 'handles exceptions correctly' do
+      expect { with_buildpack { |buildpack| raise 'an exception' } }.to raise_error SystemExit
+      expect($stderr.string).to match(/an exception/)
+    end
+
     def with_buildpack(&block)
       JavaBuildpack::Diagnostics::LoggerFactory.send :close # suppress warnings
       Dir.mktmpdir do |root|
