Add IndexTags post-checkout hook

Change-Id: Id7858b3f51fa320a6a10be78eecd602563fda6ac
Reviewed-on: http://gerrit.causes.com/35566
Reviewed-by: Shane da Silva <shane@causes.com>
Tested-by: Shane da Silva <shane@causes.com>

Author: sds

TODO

@@ -22,6 +22,7 @@ Display when a hook has been explicitly skipped when it would otherwise run
 Display when no applicable hooks ran (e.g. instead of "All pre-commit checks passed")
 Add pre-commit check ensuring Gemfile.lock matches Gemfile (unless in .gitignore)
 Add check for https://github.com/mdevils/node-jscs
+Add post-checkout check for asking to update git submodules
 
 
 Allow features of hooks to be customized (stealth, required, etc.)

config/default.yml

@@ -20,6 +20,8 @@ post_checkout:
     include:
       - 'Gemfile'
       - 'Gemfile.lock'
+  IndexTags:
+    description: 'Indexing source code tags'
 
 # Hooks that are run after `git commit` is executed, before the commit message
 # editor is displayed. These hooks are ideal for syntax checkers, linters, and

lib/overcommit/hook/post_checkout/index_tags.rb

@@ -0,0 +1,24 @@
+module Overcommit::Hook::PostCheckout
+  # Scans source code each time HEAD changes to generate an up-to-date index of
+  # all function/variable definitions, etc.
+  class IndexTags < Base
+    def run
+      unless in_path?('ctags')
+        return :good # Silently ignore
+      end
+
+      index_tags_in_background
+
+      :good
+    end
+
+  private
+
+    SCRIPT_LOCATION = Overcommit::Utils.script_path('index-tags')
+
+    def index_tags_in_background
+      # TODO: come up with Ruby 1.8-friendly way to do this
+      Process.detach(Process.spawn(SCRIPT_LOCATION))
+    end
+  end
+end

libexec/scripts/index-tags

@@ -6,13 +6,11 @@
 
 set -e
 
-ctags --version &> /dev/null || exit 0
-
 trap "rm -f .git/tags.$$" EXIT
 err_file=.git/ctags.err
 if ctags --tag-relative -Rf.git/tags.$$ --exclude=.git "$@" 2>${err_file}; then
   mv .git/tags.$$ .git/tags
-  [ -e ${err_file} ] && rm ${err_file}
+  [ -e ${err_file} ] && rm -f ${err_file}
 else
   # Ignore STDERR unless `ctags` returned a non-zero exit code
   cat ${err_file}

spec/overcommit/hook/post_checkout/index_tags_spec.rb

@@ -0,0 +1,24 @@
+require 'spec_helper'
+
+describe Overcommit::Hook::PostCheckout::IndexTags do
+  let(:config)  { Overcommit::ConfigurationLoader.default_configuration }
+  let(:context) { double('context') }
+  let(:subject) { described_class.new(config, context) }
+
+  before do
+    subject.stub(:in_path?).and_return(installed)
+    subject.stub(:index_tags_in_background)
+  end
+
+  context 'when ctags is not installed' do
+    let(:installed) { false }
+
+    it { should pass }
+  end
+
+  context 'when ctags is installed' do
+    let(:installed) { true }
+
+    it { should pass }
+  end
+end