Add IndexTags hook for post-{commit,merge,rewrite}

Add support for updating ctags all the time, based on an article from
the illustrious Tim Pope:

http://tbaggery.com/2011/08/08/effortless-ctags-with-git.html

Change-Id: I8d515cd69ca80c35f760a1f1b7a7484ee1e40871
Reviewed-on: http://gerrit.causes.com/46993
Tested-by: jenkins <jenkins@brigade.com>
Reviewed-by: Shane da Silva <shane.dasilva@brigade.com>

Author: sds

CHANGELOG.md

@@ -17,6 +17,8 @@
   replace the old value instead of appending to it
 * Add `execute_in_background` helper to provide a standardized way to start
   long-running processes without blocking the hook run
+* Add `IndexTags` hook for `post-commit`, `post-merge`, and `post-rewrite`
+  hook types so tags index can always be kept up to date via `ctags`
 
 ## 0.22.0
 

config/default.yml

@@ -291,6 +291,7 @@ PostCheckout:
   IndexTags:
     enabled: false
     description: 'Generating tags file from source'
+    required_executable: 'ctags'
 
 # Hooks that run after a commit is created.
 PostCommit:
@@ -307,14 +308,29 @@ PostCommit:
     flags: ['HEAD~', 'HEAD']
     install_command: 'npm install -g git-guilt'
 
+  IndexTags:
+    enabled: false
+    description: 'Generating tags file from source'
+    required_executable: 'ctags'
+
 # Hooks that run after `git merge` executes successfully (no merge conflicts).
 PostMerge:
   ALL:
     requires_files: false
     quiet: false
 
+  IndexTags:
+    enabled: false
+    description: 'Generating tags file from source'
+    required_executable: 'ctags'
+
 # Hooks that run after a commit is modified by an amend or rebase.
 PostRewrite:
   ALL:
     requires_files: false
     quiet: false
+
+  IndexTags:
+    enabled: false
+    description: 'Generating tags file from source'
+    required_executable: 'ctags'

lib/overcommit/hook/post_checkout/index_tags.rb

@@ -6,10 +6,6 @@ class IndexTags < Base
     SCRIPT_LOCATION = Overcommit::Utils.script_path('index-tags')
 
     def run
-      unless in_path?('ctags')
-        return :pass # Silently ignore
-      end
-
       ctags_args = Array(config['ctags_arguments'])
       execute_in_background([SCRIPT_LOCATION] + ctags_args)
 

lib/overcommit/hook/post_commit/index_tags.rb

@@ -0,0 +1,14 @@
+module Overcommit::Hook::PostCommit
+  # Updates ctags index for all source code in the repository.
+  class IndexTags < Base
+    # Location of the tag indexing script.
+    SCRIPT_LOCATION = Overcommit::Utils.script_path('index-tags')
+
+    def run
+      ctags_args = Array(config['ctags_arguments'])
+      execute_in_background([SCRIPT_LOCATION] + ctags_args)
+
+      :pass
+    end
+  end
+end

lib/overcommit/hook/post-merge/base.rb lib/overcommit/hook/post_merge/base.rb

@@ -0,0 +1,14 @@
+module Overcommit::Hook::PostMerge
+  # Updates ctags index for all source code in the repository.
+  class IndexTags < Base
+    # Location of the tag indexing script.
+    SCRIPT_LOCATION = Overcommit::Utils.script_path('index-tags')
+
+    def run
+      ctags_args = Array(config['ctags_arguments'])
+      execute_in_background([SCRIPT_LOCATION] + ctags_args)
+
+      :pass
+    end
+  end
+end

lib/overcommit/hook/post_merge/index_tags.rb

@@ -0,0 +1,17 @@
+module Overcommit::Hook::PostRewrite
+  # Updates ctags index for all source code in the repository.
+  class IndexTags < Base
+    # Location of the tag indexing script.
+    SCRIPT_LOCATION = Overcommit::Utils.script_path('index-tags')
+
+    def run
+      # Ignore unless this is a rebase (amends are covered by post-commit hook)
+      return :pass unless rebase?
+
+      ctags_args = Array(config['ctags_arguments'])
+      execute_in_background([SCRIPT_LOCATION] + ctags_args)
+
+      :pass
+    end
+  end
+end

lib/overcommit/hook/post-rewrite/base.rb lib/overcommit/hook/post_rewrite/base.rb

@@ -6,19 +6,8 @@
   subject { described_class.new(config, context) }
 
   before do
-    subject.stub(:in_path?).and_return(installed)
     subject.stub(:execute_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
+  it { should pass }
 end

lib/overcommit/hook/post_rewrite/index_tags.rb

@@ -0,0 +1,13 @@
+require 'spec_helper'
+
+describe Overcommit::Hook::PostCommit::IndexTags do
+  let(:config)  { Overcommit::ConfigurationLoader.default_configuration }
+  let(:context) { double('context') }
+  subject { described_class.new(config, context) }
+
+  before do
+    subject.stub(:execute_in_background)
+  end
+
+  it { should pass }
+end

spec/overcommit/hook/post_checkout/index_tags_spec.rb

@@ -0,0 +1,13 @@
+require 'spec_helper'
+
+describe Overcommit::Hook::PostMerge::IndexTags do
+  let(:config)  { Overcommit::ConfigurationLoader.default_configuration }
+  let(:context) { double('context') }
+  subject { described_class.new(config, context) }
+
+  before do
+    subject.stub(:execute_in_background)
+  end
+
+  it { should pass }
+end

spec/overcommit/hook/post_commit/index_tags_spec.rb

@@ -0,0 +1,13 @@
+require 'spec_helper'
+
+describe Overcommit::Hook::PostMerge::IndexTags do
+  let(:config)  { Overcommit::ConfigurationLoader.default_configuration }
+  let(:context) { double('context') }
+  subject { described_class.new(config, context) }
+
+  before do
+    subject.stub(:execute_in_background)
+  end
+
+  it { should pass }
+end