Tricking Bundler

Rome Ruby Social Club - March 23, 2012

Tricking Bundleraka developing app & gem w/o roundtripsaka no moregem.git (at master) is not checked out. Please run `bundle install`

Saturday, March 24, 2012

Rome Ruby Social Club - March 23, 2012

Bundler + Git

Gem dependencies manager (that gets caching right ;-)

Allows to install gems from Git repositories

This trick is for Git gems only

Saturday, March 24, 2012

Rome Ruby Social Club - March 23, 2012

How does it work

Parses Gemfile & Gemfile.lock

git fetch && git checkout in`gem environment gemdir`/bundler/gems/$NAME-$REF12

Add the checked out directory to Ruby’s $LOAD_PATH

Saturday, March 24, 2012

Rome Ruby Social Club - March 23, 2012

Problem

Your project is in ~/code/app

Your gem is in ~/code/gem

You run the app and need to change the gem code

cd ~/code/gem; <code>; git commit; git push; cd ~/code/app; bundle up gem # DOESN’T fit the job

Saturday, March 24, 2012

Rome Ruby Social Club - March 23, 2012

Symlinks to the rescue!

Bundler directory contains all git-fetched gems with this format:

$GEM_NAME-$REF12 (first 12 chars of the HEAD SHA1 commit id)

Bash script gets ~/code/gems HEAD ref && ln -s ~/code/gem to the directory bundler expects the gem in

Profit!

Saturday, March 24, 2012

Rome Ruby Social Club - March 23, 2012

Solution

You edit the gem code directly in your ~/code/gem - app picks it up

Once done, git commit && git show to get HEAD SHA1 id

Update SHA1 in Gemfile.lock directly

symlink-gem ../gem

Saturday, March 24, 2012

Rome Ruby Social Club - March 23, 2012

Switching branches?

master branch needs commit c4feb4be

develop branch needs commit de4db3ef

(develop) git co master; for gem in a b c d; do symlink-gem ../$gem; done# DOESN’T cut the job either ;-)

Saturday, March 24, 2012

Rome Ruby Social Club - March 23, 2012

Bundle::LockFileParser is your friend

Ruby script gets all dependencies in a nicely wrapped Array of Sources

For each Git-fetched $gem, check out the commit required by Gemfile.lock in your ~/code/$gem

%x{ symlink-gem #{gem} }

Why not git post-checkout-hook? :)

Saturday, March 24, 2012

Rome Ruby Social Club - March 23, 2012

Switch branchesw/post-checkout-hook

18:04:02 [vjt@debian ~/code/app] (develop) $ git co master Switched to branch 'master'

[git://github.com/vjt/rtf.git] Already on 'master'

[git://github.com/vjt/dep1.git] HEAD is now at df61eac... Fixed stuff

[git://github.com/vjt/dep2.git] Previous HEAD position was 45509fa... Experimental stuffSwitched to branch 'master'

[git://github.com/ifad/activerecord-sybase-adapter.git] Already on 'master'

Saturday, March 24, 2012

Rome Ruby Social Club - March 23, 2012

Thanks!

@vjt

[email protected]

http://sindro.me/

http://github.com/vjt

Saturday, March 24, 2012