I am trying to contribute to a Ruby gem and I don't understand how to test a local gem without using a globally installed gem.
The gem I want to contribute to is a command line interface gem. I clone the gem into a directory then cd into that directory. However, when I run commands in the terminal when I'm in the cloned project directory it still uses the global gem. I've even run
gem uninstall gemname
then while inside the newly cloned gem directory I redo
gem install gemname.
No matter what changes I make to the gem, I can't see the results or what my contributions are doing because it's always running the global gem.
When I do try to type a command line command that is supposed to interact with the gem while in the cloned gem directory I get:
-bash: ~/.gem/ruby/2.1.0/bin/githubrepo: No such file or directory
I've done a ton of research but I'm just not getting it. Help?
gem install gemname will look for a .gem file in the current directory. If not found it will look for it on the web.
gem install --local /path/to/your/gemname.gem will allow you to target a particular directory. You may need to gem build gemname.gemspec first, so it has your changes.
Instead of doing this, I would write tests in the gem directory itself. It's likely that when running code in there, you can simply require 'gemname' in Ruby to get the gem functionality.
If it's a well-written gem, it should have tests already. They will most likely be in a directory called test or spec. Have a look at these tests and try to carry on in that style to test your changes. This will make your code changes far far more likely to be accepted as a pull request.
Related
How do I configure bundler so that when I run bundle install it looks for gems under /my/custom/path first and if it doesn't find there then try to fetch them from a ruby gem remote repository hosted under https://a.nice.host and downloads those into ./local/relative/path (relative to cwd for example). I would like to avoid the bundler looking at default gem installation system path or rubygems.org
The syntax for sourcing a gem from a local folder is:
gem 'some-gem-name', path: '/my/custom/path'
And the syntax for specifying a custom source is:
gem 'another-gem-name', source: 'https://a.nice.host'
And to install gems into a specific local folder, you can run:
bundle install --path ./local/relative/path
Now, that's probably all the tools you need, in truth... (And in fact, especially for that last requirement, you may instead wish to look into rvm gemsets, or using bundle install --deployment.)
But you did also ask about "looking in a local folder first, and only falling back to a remote source if it doesn't exist". That's quite an odd requirement (usually you'd only want to explicitly opt-in to fetching gems from a local path?!), but to answer this question as you've asked it...
A Gemfile is literally just ruby code! So you can define this logic using... You guessed it, ruby! For example:
if File.exists?('/my/custom/path')
gem 'some-gem-name', path: '/my/custom/path'
else
gem 'some-gem-name', source: 'https://a.nice.host'
end
If this (unusual) pattern needs to be repeated in multiple places, you could wrap it into some helper method.
For more information on the configuration options of bundler, please see the documentation.
I'm developing a couple of private gems and I think I don't understand correctly the PATH/GEM_PATH and/or Bundler/RVM installation flow, would love if someone could chip in.
I have a repository with two gems (A & B for simplicity sake). I've developed the gems using the scaffolding + following the guidelines provided by this bundler tutorial.
Thanks to the Bundler project I have a few Rakefile tasks like rake build, rake install, rake install:local and rake release. Because of the private nature of these gems I can't release them to RubyGems (and we haven't looked into hosting our rubygems).
My machines are using RVM to manage ruby versions and Bundler version 1.15.1
What I want to do: Assuming a new machine/developer trying out the project, ideally we would cd into each of the subfolders (currently 2, gem A and gem B), run rake install and after that we should have the gems available system wide for the current user.
What is happening: The gems are built and work properly, but they are only available inside the subfolder of each gem i.e. gem A is only available inside the subfolder A and gem B is only available inside subfolder B.
What I've tried: So, after rake build/install/install:local a new .gem file is generated under pkg. I've tried to manually install the "compiled" file using gem install pkg/A.gem, gem install --local pkg/A.gem and gem install --local --user-install pkg/A.gem without success. (there are plenty of SO questions/answers about this)
I believe this has something to do with the PATH variables, but like I said before I don't fully understand the way they are managed. I get the following results from these commands:
# Our gem
> gem which A
/home/ubuntu/.rvm/gems/ruby-2.4.0/gems/A-0.1.8/lib/A.rb
# Pry, available globally
> gem which pry
/home/ubuntu/.rvm/gems/ruby-2.4.0/gems/pry-0.11.1/lib/pry.rb
I've been lost and frustrated for far too long now, any help is appreciated. Also open to hear suggestions of better private gem installation flows :)
Yes, it has something to do with your PATH variables. Your installation seems to be good.
I advise you to first affirm your gems installation path with:
echo $GEM_HOME
The double check your PATH to ensure its present and also confirm that the GEM home is also where the gem got installed into from the rake install
echo $PATH
If not, put it in your path and you should be fine with something like this:
echo PATH=$PATH:$GEM_HOME >> ~/.bashrc
source ~/.bashrc
Build your gem as per that guide you linked. You should end up with a gem file. Distribute this as you see fit (I use rsync/crontab to download newer gem versions but anything goes). User can install the gem as follows:
gem install --user-install /path/to/your/file.gem
This will install the gem in the user's ~/.gem/ruby/<version>/gems/<your-gem-name> directory.
Tried it with an empty gem (foodie, as in that example guide) and it works fine. But if you don't specify the --user-install parameter it will try to install in the system ruby dir (/usr/lib/ruby/gems...)
For a project I'm working on, I have to do some work on an existing Ruby Gem. I haven't got much previous experience with Ruby and am struggling with a few aspects.
I have the repository cloned locally. I need to edit the current files in the /lib/ directory, which I can do. Is it possible for me to compile the edited files into a Gem and run this Gem? Any help would be really appreciated.
Yes! You can include the gem in a local project and point the Gemfile to your local directory:
Gemfile
source 'https://rubygems.org'
gem 'my_local_gem', path: '/absolute/path/to/your/gem'
Then edit the gem, run your local program and see the changes.
Additionally, you don't always have to clone a whole gem, you can install it via rubygems and use bundle open <gem_name> to open the gem's contents in your supplied editor.
I have written a post describing just that and more here.
I forked a gem I use a lot in order to code some enhancements on it. I want it to be installed in a subfolder called ~/codebase/ruby, where I keep all my Ruby projects, arranged in subdirectories.
To do that, I built and installed the gem with the following commands:
gem build my_gem.gemspec
gem install mygem-x.x.gem -i./mygem
mygem is installed in ~/codebase/ruby/mygem. I can't get my client code (which is in another directory) to grab mygem from there.
I've tried all of the following without success:
Running ruby with argument -I<path_to_mygem>.
Adding <path_to_mygem> to PATH.
Putting :gempath: <path_to_mygem> into ~/.gemrc.
I know I could put the gem in ~/.gem/ruby/<version> (since it appears in gem env) and that would probably work, but that would break my existing directory structure of Ruby code, forcing me to code in a different directory only for mygem, which is something I want to avoid unless it's the only option.
Thoughts?
Hopefully you are using Bundler to load the required gems. Then you just specify the path to the gem file in your Gemfile:
gem 'my_gem', :path => '~/codebase/ruby/mygem'
Ruby dabbler/newbie here who's not familiar with the ecosystem, so apologies if this is one of those super duh questions.
Is there a way to view all the files and/or source code installed by a gem? That is, I just ran
$ gem install sass
And the sass gem is now a part of my local system
$ gem list --local
...
sass (3.1.16, 3.1.2)
...
I want to know what the gem install command put on my system. Is there a command I can run to see all the files installed by the gem?
After some googling, man gem and gem help commands, I discovered the contents command.
$ gem contents sass
However, when I run this command with the aforementioned sass gem, I get the following results
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/engine_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/functions_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/extend_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/logger_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/css2sass_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/conversion_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/script_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/util/subset_map_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/util/multibyte_string_scanner_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/callbacks_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/importer_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/scss/css_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/scss/scss_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/scss/rx_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/util_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/script_conversion_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/less_conversion_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/cache_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/test/sass/plugin_test.rb
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/bin/sass
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/bin/sass-convert
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.16/bin/scss
However, this list seems incomplete as I know there are files in
.../.rvm/gems/ruby-1.9.2-p180/gems/sass-3.1.2/lib/
Why does contents not show the files from lib?
Is it possible for a gem installer to install files outside of the gems folder?
Is there a command that can show everything installed by a gem?
gem has an unpack command: http://guides.rubygems.org/command-reference/#gem-unpack
gem unpack rake
ls rake-0.4.3/
There are two really good ways to do this. There is another gem which allows you to open the gem and edit. This gem is call gem-open
gem install gem-open
then
gem open sass
Another way is to generate your own rdocs.
gem rdoc sass
You can then look at your rdocs by
gem server
Also if you are using rvm, you can type rvm info and it will show GEM_HOME location.
This will be where all your gems source code is.
cd $GEM_HOME
cd gems/sass-3.1.2/
Update:
This is the way I mostly do this now, when using bundler.
cd $(bundle show sass)
This will be the version of sass in your Gemfile.
I usually open a gem by running this command from the console
EDITOR=<your editor> bundle open <name of gem>
The lib/ directory you mentioned is for version 3.1.2 of the gem; gem contents without --version will just list one version (it appears to pick the newest version, but I'm unable to verify this is always true). What output do you get for gem contents --version 3.1.2 sass?
You can also use just rename the .gem file to .tar and extract as a posix archive. The source code is inside it in the lib folder. See https://blog.srcclr.com/extracting-ruby-source-code-from-gem-packages/ for more details.
In addition to gem contents, another command you might find useful is gem environment. If you have multiple paths for your gem installations, they will all be listed under the "GEM PATHS" label.