Add GitHub Actions annotations

It is possible to get inline annotations with GitHub Actions. This is
based on Rubocop's formatter.

It's implemented as a configuration option that's dynamic by default.
This means it will show up in actions, but not in other environments.
Overriding is still possible.

Author: ekohl

lib/puppet-lint.rb

@@ -7,6 +7,7 @@
 require 'puppet-lint/configuration'
 require 'puppet-lint/data'
 require 'puppet-lint/checks'
+require 'puppet-lint/report/github'
 require 'puppet-lint/bin'
 require 'puppet-lint/monkeypatches'
 
@@ -121,6 +122,16 @@ def format_message(message)
     puts "  #{message[:reason]}" if message[:kind] == :ignored && !message[:reason].nil?
   end
 
+  # Internal: Format a problem message and print it to STDOUT so GitHub Actions
+  # recognizes it as an annotation.
+  #
+  # message - A Hash containing all the information about a problem.
+  #
+  # Returns nothing.
+  def print_github_annotation(message)
+    puts PuppetLint::Report::GitHubActionsReporter.format_problem(path, message)
+  end
+
   # Internal: Get the line of the manifest on which the problem was found
   #
   # message - A Hash containing all the information about a problem.
@@ -167,6 +178,8 @@ def report(problems)
         format_message(message)
         print_context(message) if configuration.with_context
       end
+
+      print_github_annotation(message) if configuration.github_actions
     end
     puts JSON.pretty_generate(json) if configuration.json
 

lib/puppet-lint/configuration.rb

@@ -152,6 +152,7 @@ def defaults
       self.json = false
       self.show_ignored = false
       self.ignore_paths = ['vendor/**/*.pp']
+      self.github_actions = ENV.key?('GITHUB_ACTION')
     end
   end
 end

lib/puppet-lint/report/github.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+class PuppetLint
+  module Report
+    # This formatter formats report data as GitHub Workflow commands resulting
+    # in GitHub check annotations when run within GitHub Actions.
+    class GitHubActionsReporter
+      ESCAPE_MAP = { '%' => '%25', "\n" => '%0A', "\r" => '%0D' }.freeze
+
+      def self.format_problem(file, problem)
+        format(
+          "\n::%<severity>s file=%<file>s,line=%<line>d,col=%<column>d::%<message>s (check: %<check>s)\n",
+          :severity => problem[:kind],
+          :file => file,
+          :line => problem[:line],
+          :column => problem[:column],
+          :message => github_escape(problem[:message]),
+          :check => problem[:check]
+        )
+      end
+
+      def self.github_escape(string)
+        string.gsub(Regexp.union(ESCAPE_MAP.keys), ESCAPE_MAP)
+      end
+    end
+  end
+end

spec/puppet-lint/configuration_spec.rb

@@ -49,7 +49,10 @@
   end
 
   it 'should be able to set sane defaults' do
-    subject.defaults
+    override_env do
+      ENV.delete('GITHUB_ACTION')
+      subject.defaults
+    end
 
     expect(subject.settings).to eq(
       'with_filename'    => false,
@@ -58,9 +61,27 @@
       'log_format'       => '',
       'with_context'     => false,
       'fix'              => false,
+      'github_actions'   => false,
       'show_ignored'     => false,
       'json'             => false,
       'ignore_paths'     => ['vendor/**/*.pp']
     )
   end
+
+  it 'detects github actions' do
+    override_env do
+      ENV['GITHUB_ACTION'] = 'action'
+      subject.defaults
+    end
+
+    expect(subject.settings['github_actions']).to be(true)
+  end
+
+  def override_env
+    old_env = ENV.clone
+    yield
+  ensure
+    ENV.clear
+    ENV.update(old_env)
+  end
 end

spec/spec_helper.rb

@@ -1,3 +1,6 @@
+# Disable GitHub Actions reporting since it breaks the test suite
+ENV.delete('GITHUB_ACTION')
+
 if ENV['COVERAGE'] == 'yes' && RUBY_VERSION.start_with?('2.6.')
   require 'simplecov'
   SimpleCov.start do