Initial Danger integration

Fixes #843

.travis.yml

@@ -13,6 +13,7 @@ matrix:
       env: JOB=SPM
       os: osx
       osx_image: xcode8.2
+      before_script: bundle exec danger
     - script: make docker_test
       env: JOB=Linux
       sudo: required

Dangerfile

@@ -0,0 +1,26 @@
+# Warn when there is a big PR
+warn("Big PR") if git.lines_of_code > 500
+
+# Sometimes its a README fix, or something like that - which isn't relevant for
+# including in a CHANGELOG for example
+has_app_changes = !git.modified_files.grep(/Source/).empty?
+has_test_changes = !git.modified_files.grep(/Tests/).empty?
+
+# Add a CHANGELOG entry for app changes
+if !git.modified_files.include?("CHANGELOG.md") && has_app_changes
+  fail("Please include a CHANGELOG entry to credit yourself! \nYou can find it at [CHANGELOG.md](https://github.com/realm/SwiftLint/blob/master/CHANGELOG.md).")
+    markdown <<-MARKDOWN
+Here's an example of your CHANGELOG entry:
+```markdown
+* #{github.pr_title}#{' '}
+[#{github.pr_author}](https://github.com/#{github.pr_author})
+[#issue_number](https://github.com/realm/SwiftLint/issues/issue_number)
+```
+*note*: There are two invisible spaces after the entry's text.
+MARKDOWN
+end
+
+# Non-trivial amounts of app changes without tests
+if git.lines_of_code > 50 && has_app_changes && !has_test_changes
+  warn "This PR may need tests."
+end

Gemfile

@@ -0,0 +1,4 @@
+# frozen_string_literal: true
+source "https://rubygems.org"
+
+gem "danger"

Gemfile.lock

@@ -0,0 +1,51 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    addressable (2.5.0)
+      public_suffix (~> 2.0, >= 2.0.2)
+    claide (1.0.1)
+    claide-plugins (0.9.2)
+      cork
+      nap
+      open4 (~> 1.3)
+    colored (1.2)
+    cork (0.2.0)
+      colored (~> 1.2)
+    danger (4.0.3)
+      claide (~> 1.0)
+      claide-plugins (>= 0.9.2)
+      colored (~> 1.2)
+      cork (~> 0.1)
+      faraday (~> 0.9)
+      faraday-http-cache (~> 1.0)
+      git (~> 1)
+      kramdown (~> 1.5)
+      octokit (~> 4.2)
+      terminal-table (~> 1)
+    faraday (0.10.0)
+      multipart-post (>= 1.2, < 3)
+    faraday-http-cache (1.3.1)
+      faraday (~> 0.8)
+    git (1.3.0)
+    kramdown (1.13.1)
+    multipart-post (2.0.0)
+    nap (1.1.0)
+    octokit (4.6.2)
+      sawyer (~> 0.8.0, >= 0.5.3)
+    open4 (1.3.4)
+    public_suffix (2.0.4)
+    sawyer (0.8.1)
+      addressable (>= 2.3.5, < 2.6)
+      faraday (~> 0.8, < 1.0)
+    terminal-table (1.7.3)
+      unicode-display_width (~> 1.1.1)
+    unicode-display_width (1.1.2)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  danger
+
+BUNDLED WITH
+   1.13.6