eric · March 8, 2012 06:11 · Mar 8, 2012
diff --git a/bundle-outdated-github.rb b/bundle-outdated-github.rb
@@ -0,0 +1,57 @@
+#!/usr/bin/env ruby
+
+#
+# Annotate your "bundle outdated" with GitHub compare URLs
+#
+
+require 'open-uri'
+require 'json'
+
+def rubygems_gem_info(gem_name)
+  JSON.parse(`curl -s https://rubygems.org/api/v1/gems/#{gem_name}.json`)
+end
+
+def github_repo_tags(repo)
+  JSON.parse(`curl -s https://api.github.com/repos/#{repo}/tags`)
+end
+
+def rubygems_github_repo(gem_name)
+  if gem_info = rubygems_gem_info(gem_name)
+    %w(source_code_uri project_uri homepage_uri).each do |key|
+      if repo_name = gem_info[key].to_s[%r{//github\.com/([^/]+/[^/]+)}, 1]
+        return repo_name
+      end
+    end
+  end
+  nil
+end
+
+def github_compare_url(gem_name, first_version, second_version)
+  if github_repo = rubygems_github_repo(gem_name)
+    tags = github_repo_tags(github_repo)
+    return unless tags.is_a?(Array)
+    tags = tags.sort_by { |tag| tag['name'].length }
+
+    first_tag  = tags.detect { |tag| tag['name'].index(first_version) }
+    second_tag = tags.detect { |tag| tag['name'].index(second_version) }
+
+    if first_tag && second_tag
+      "https://github.com/#{github_repo}/compare/#{first_tag['name']}...#{second_tag['name']}"
+    end
+  end
+end
+
+IO.popen('bundle outdated', 'r') do |io|
+  io.each_line do |line|
+    line = line.chomp
+    if m = line.match(/^\s+\* (\S+) \((\S+) > (\S+)\)/)
+      if url = github_compare_url(m[1], m[3], m[2])
+        puts "#{line} — #{url}"
+      else
+        puts line
+      end
+    else
+      puts line
+    end
+  end
+end