Have you updated CHANGELOG.md?

.rspec

@@ -0,0 +1,2 @@
+--color
+--format=documentation

.rubocop.yml

@@ -0,0 +1 @@
+inherit_from: .rubocop_todo.yml

.rubocop_todo.yml

@@ -0,0 +1,39 @@
+# This configuration was generated by
+# `rubocop --auto-gen-config`
+# on 2016-08-26 14:48:21 -0400 using RuboCop version 0.42.0.
+# The point is for the user to remove these configuration records
+# one by one as the offenses are removed from the code base.
+# Note that changes in the inspected code, or installation of new
+# versions of RuboCop, may require this file to be generated again.
+
+# Offense count: 1
+Metrics/AbcSize:
+  Max: 16
+
+# Offense count: 6
+# Configuration parameters: AllowHeredoc, AllowURI, URISchemes.
+# URISchemes: http, https
+Metrics/LineLength:
+  Max: 242
+
+# Offense count: 1
+# Configuration parameters: CountComments.
+Metrics/MethodLength:
+  Max: 12
+
+# Offense count: 1
+Style/Documentation:
+  Exclude:
+    - 'spec/**/*'
+    - 'test/**/*'
+    - 'lib/changelog/plugin.rb'
+
+# Offense count: 2
+# Configuration parameters: NamePrefix, NamePrefixBlacklist, NameWhitelist.
+# NamePrefix: is_, has_, have_
+# NamePrefixBlacklist: is_, has_, have_
+# NameWhitelist: is_a?
+Style/PredicateName:
+  Exclude:
+    - 'spec/**/*'
+    - 'lib/changelog/plugin.rb'

CHANGELOG.md

@@ -2,4 +2,5 @@
 
 ### 0.1.0 (Next)
 
+* [#1](https://github.com/dblock/danger-changelog/pull/1): Added `have_you_updated_changelog?`, have you updated CHANGELOG.md? - [@dblock](https://github.com/dblock).
 * Your contribution here.

Dangerfile

@@ -0,0 +1,3 @@
+# danger.systems
+
+changelog.check

Gemfile

@@ -1,4 +1,3 @@
 source 'https://rubygems.org'
 
-# Specify your gem's dependencies in danger-changelog.gemspec
 gemspec

README.md

@@ -10,8 +10,17 @@ A plugin that is OCD about your CHANGELOG format.
 
 ## Usage
 
-    Methods and attributes from this plugin are available in
-    your `Dangerfile` under the `changelog` namespace.
+Methods and attributes from this plugin are available in your `Dangerfile` under the `changelog` namespace.
+
+### changelog.check
+
+Run all checks with defaults.
+
+### changelog.have_you_updated_changelog?
+
+Checks whether you have updated CHANGELOG.md.
+
+![](images/have_you_updated_changelog.png)
 
 ## Development
 

Rakefile

@@ -4,7 +4,7 @@ require 'rubocop/rake_task'
 
 RSpec::Core::RakeTask.new(:specs)
 
-task default: :specs
+task default: [:rubocop, :specs]
 
 task :spec do
   Rake::Task['specs'].invoke

danger-changelog.gemspec

@@ -8,12 +8,12 @@ Gem::Specification.new do |spec|
   spec.version       = Changelog::VERSION
   spec.authors       = ['dblock']
   spec.email         = ['[email protected]']
-  spec.description   = %q{A danger.systems plugin that is OCD about your CHANGELOG.}
-  spec.summary       = %q{A danger.systems plugin that is OCD about your CHANGELOG.}
+  spec.description   = 'A danger.systems plugin that is OCD about your CHANGELOG.'
+  spec.summary       = 'A danger.systems plugin that is OCD about your CHANGELOG.'
   spec.homepage      = 'https://github.com/dblock/danger-changelog'
   spec.license       = 'MIT'
 
-  spec.files         = `git ls-files`.split($/)
+  spec.files         = `git ls-files`.split($INPUT_RECORD_SEPARATOR)
   spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ['lib']
@@ -23,8 +23,8 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'bundler', '~> 1.3'
   spec.add_development_dependency 'rake', '~> 10.0'
   spec.add_development_dependency 'rspec', '~> 3.4'
-  spec.add_development_dependency "rubocop", "~> 0.41"
-  spec.add_development_dependency "yard", "~> 0.8"
+  spec.add_development_dependency 'rubocop', '~> 0.41'
+  spec.add_development_dependency 'yard', '~> 0.8'
   spec.add_development_dependency 'guard', '~> 2.14'
   spec.add_development_dependency 'guard-rspec', '~> 4.7'
   spec.add_development_dependency 'listen', '3.0.7'

lib/changelog/gem_version.rb

@@ -1,3 +1,3 @@
 module Changelog
-  VERSION = "0.1.0".freeze
+  VERSION = '0.1.0'.freeze
 end

lib/changelog/plugin.rb

@@ -1,4 +1,42 @@
 module Danger
+  # CHANGELOG OCD in your projects.
+  #
+  # @example Checking for everuthing
+  #
+  #          changelog.check
+  #
+  # @see  dblock/danger-changelog
+  # @tags changelog
+
   class DangerChangelog < Plugin
+    # Has the CHANGELOG file been modified?
+    # @return [boolean]
+    def has_changelog_changes?
+      git.modified_files.include?('CHANGELOG.md')
+    end
+
+    # Runs all checks.
+    # @return [void]
+    def check
+      have_you_updated_changelog?
+    end
+
+    # Have you updated CHANGELOG.md?
+    # @return [boolean]
+    def have_you_updated_changelog?
+      if has_changelog_changes?
+        true
+      else
+        markdown <<-MARKDOWN
+Here's an example of a CHANGELOG.md entry:
+
+```markdown
+* [##{github.pr_json[:number]}](#{github.pr_json[:html_url]}): #{github.pr_title} - [@#{github.pr_author}](https://github.com/#{github.pr_author}).
+```
+MARKDOWN
+        warn "Unless you're refactoring existing code, please update CHANGELOG.md.", sticky: false
+        false
+      end
+    end
   end
 end

spec/changelog_spec.rb

@@ -7,11 +7,53 @@ module Danger
     end
 
     describe 'with Dangerfile' do
-      before do
-        @dangerfile = testing_dangerfile
-        @my_plugin = @dangerfile.my_plugin
+      let(:dangerfile) { testing_dangerfile }
+      let(:changelog) { testing_dangerfile.changelog }
+      let(:status_report) { changelog.status_report }
+
+      describe 'in a PR' do
+        before do
+          # typical PR JSON looks like https://raw.githubusercontent.com/danger/danger/bffc246a11dac883d76fc6636319bd6c2acd58a3/spec/fixtures/pr_response.json
+          changelog.env.request_source.pr_json = {
+            number: 123,
+            title: 'being dangerous',
+            html_url: 'https://github.com/dblock/danger-changelog/pull/123',
+            user: {
+              login: 'dblock'
+            }
+          }
+        end
+
+        context 'have_you_updated_changelog?' do
+          subject do
+            changelog.have_you_updated_changelog?
+          end
+
+          context 'without CHANGELOG changes' do
+            before do
+              allow(changelog.git).to receive(:modified_files).and_return([])
+            end
+
+            it 'complains when no CHANGELOG can be found' do
+              expect(subject).to be false
+              expect(status_report[:warnings]).to eq ["Unless you're refactoring existing code, please update CHANGELOG.md."]
+              expect(status_report[:markdowns]).to eq ["Here's an example of a CHANGELOG.md entry:\n\n```markdown\n* [#123](https://github.com/dblock/danger-changelog/pull/123): being dangerous - [@dblock](https://github.com/dblock).\n```\n"]
+            end
+          end
+
+          context 'with CHANGELOG changes' do
+            before do
+              allow(changelog.git).to receive(:modified_files).and_return(['CHANGELOG.md'])
+            end
+
+            it 'has no complaints' do
+              expect(subject).to be true
+              expect(status_report[:warnings]).to eq []
+              expect(status_report[:markdowns]).to eq []
+            end
+          end
+        end
       end
     end
   end
 end
-

spec/spec_helper.rb

@@ -1,7 +1,7 @@
 require 'pathname'
 ROOT = Pathname.new(File.expand_path('../../', __FILE__))
-$:.unshift((ROOT + 'lib').to_s)
-$:.unshift((ROOT + 'spec').to_s)
+$LOAD_PATH.unshift((ROOT + 'lib').to_s)
+$LOAD_PATH.unshift((ROOT + 'spec').to_s)
 
 require 'bundler/setup'
 require 'pry'
@@ -11,7 +11,7 @@
 
 # Use coloured output, it's the best.
 RSpec.configure do |config|
-  config.filter_gems_from_backtrace "bundler"
+  config.filter_gems_from_backtrace 'bundler'
   config.color = true
   config.tty = true
 end
@@ -34,7 +34,7 @@ def @output.winsize
 
   cork = Cork::Board.new(out: @output)
   def cork.string
-    out.string.gsub(/\e\[([;\d]+)?m/, "")
+    out.string.gsub(/\e\[([;\d]+)?m/, '')
   end
   cork
 end
@@ -46,7 +46,7 @@ def testing_env
   {
     'HAS_JOSH_K_SEAL_OF_APPROVAL' => 'true',
     'TRAVIS_PULL_REQUEST' => '800',
-    'TRAVIS_REPO_SLUG' => 'artsy/eigen',
+    'TRAVIS_REPO_SLUG' => 'dblock/danger-changelog',
     'TRAVIS_COMMIT_RANGE' => '759adcbd0d8f...13c4dc8bb61d',
     'DANGER_GITHUB_API_TOKEN' => '123sbdq54erfsd3422gdfio'
   }