Port r7242: Add check option. #3068.

This option scans all the sources to determine if any of them have a
missing or outdated license header. If any do, it exits with status 1.
Otherwise, it exits with 0.

This is intended for use in the CI build.

git-svn-id: https://ncisvn.nci.nih.gov/svn/psc/trunk@7244 0d517254-b314-0410-acde-c619094fa49f

license_headers.rb

@@ -1,15 +1,22 @@
 #!/usr/bin/env ruby
 
 ######
-# Run this script to add/update NCIP's mandatory license headers.
+# Run this script to add/update NCIP's mandatory license headers or to verify
+# the presence of the headers in all applicable files.
 #
 # Usage:
 #   $ cd {PSC_WORKING_ROOT}
-#   $ ruby license_headers.rb
+#   $ ruby license_headers.rb [update|check]
+#
+# The `update` subcommand applies the current license to all applicable files.
+#
+# The `check` subcommand verifies that all applicable files have the license. If
+# any are missing the license, it exits with a status of 1 and prints a
+# descriptive message to standard out.
 
-class LicenseUpdater
-  attr_reader :filename, :contents
+###### UPDATE STRATEGIES
 
+class LicenseUpdater
   LICENSE_TOKEN = /\{LICENSE\}/
 
   LICENSE_HEADER_TEXT = <<-TEXT
@@ -19,32 +26,36 @@ class LicenseUpdater
 See http://ncip.github.com/psc/LICENSE for details.
 TEXT
 
+  attr_reader :filename, :contents
+
   def initialize(filename)
     @filename = filename
     @contents = File.read(filename)
   end
 
+  def needs_update?
+    new_contents != contents
+  end
+
   def update
-    $stderr.print "Processing #{filename}..."
+    File.open(filename, 'w') { |f| f.write(new_contents) } if needs_update?
+  end
 
-    new_contents =
-      if contents =~ license_pattern
-        $stderr.puts "updating existing comment."
-        contents.sub(license_pattern, license_comment)
-      else
-        $stderr.puts "adding new comment."
-        insert_new_license
-      end
-    File.open(filename, 'w') { |f| f.write(new_contents) }
+  def new_contents
+    if contents =~ license_pattern
+      contents.sub(license_pattern, license_comment)
+    else
+      with_new_license
+    end
   end
 
-  def insert_new_license
+  def with_new_license
     insert_point = license_insert_points.map { |re| contents.match(re) }.compact.first
     fail "No insert point matches for #{filename} from #{license_insert_points.inspect}" unless insert_point
 
     i = insert_point.end(0)
 
-    contents.insert(i, "#{"\n" if i != 0}#{license_comment}#{"\n" if contents.slice(i, 1) != "\n"}")
+    contents.dup.insert(i, "#{"\n" if i != 0}#{license_comment}#{"\n" if contents.slice(i, 1) != "\n"}")
   end
 
   def license_pattern
@@ -123,14 +134,64 @@ def license_header_lines
   end
 end
 
-{
-  "**/*.java" => JavaLicenseUpdater,
-  "**/*.rake" => RubyLicenseUpdater,
-  "**/*.rb" => RubyLicenseUpdater,
-  "buildfile" => RubyLicenseUpdater,
-  "**/src/**/*.xml" => XmlLicenseUpdater
-}.each do |pattern, updater|
-  Dir[pattern].each do |filename|
-    updater.new(filename).update
+###### MAIN EXECUTION
+
+class LicenseCLI
+  attr_reader :command
+
+  def initialize(args)
+    @command = args.pop
+  end
+
+  def run
+    if command && respond_to?(command)
+      send(command)
+    elsif command
+      fail "Unknown subcommand #{command.inspect}"
+    else
+      fail "Please specify update or check."
+    end
+  end
+
+  def update
+    outdated.each_with_index do |u, i|
+      $stderr.print "\rUpdating #{i + 1} / #{outdated.size}"
+      u.update
+    end
+    $stderr.puts "\rUpdated #{outdated.size} license header#{'s' unless outdated.size == 1}."
+    exit(0)
+  end
+
+  def check
+    if outdated.empty?
+      $stderr.puts "All license headers up to date."
+      exit(0)
+    else
+      $stderr.puts "#{outdated.size} files have missing or outdated license header#{'s' unless outdated.size == 1}:"
+      outdated.collect(&:filename).sort.each do |fn|
+        puts "   #{fn}"
+      end
+      exit(1)
+    end
+  end
+
+  def outdated
+    @outdated ||= updaters.select { |u| u.needs_update? }
+  end
+
+  def updaters
+    @updaters ||= {
+      "**/*.java" => JavaLicenseUpdater,
+      "**/*.rake" => RubyLicenseUpdater,
+      "**/*.rb" => RubyLicenseUpdater,
+      "buildfile" => RubyLicenseUpdater,
+      "**/src/**/*.xml" => XmlLicenseUpdater
+    }.collect { |pattern, updater_class|
+      Dir[pattern].collect { |filename|
+        updater_class.new(filename)
+      }
+    }.flatten
   end
 end
+
+LicenseCLI.new(ARGV).run