Copypasta

File generators are cool. Sometimes you need some scaffolding for things! But unless you're using Thor (and Thor is also cool) or Rails (and Rails is not cool), your options are pretty limited. Sometimes you can hack one together, in an awkward way--shout out to anyone who's ever written a bunch of Chef!--but there's no unified way that works on a CLI, embedded in your app, or in Chef.

So I decided to thereifixedit the whole thing.

Copypasta is tested primarily under Ruby 2.5. Feel free to file bugs for Ruby 2.3 or later.

Copypasta works on the concept of a Plan. A Plan is a directory structure that mimics the final data structure while offering a DSL that figures out what, exactly, should be dropped into the directory. Each directory in your Plan must have a _contents.rb file that will be evaluated with our shiny happy Copypasta DSL. _contents.rb will define files that live in that directory and how they should be built:

• copy files are copied directly over; by default, copy 'foo.txt' will look for a foo.txt at the same level as the _contents.rb file. You can specify a specific file with source:.
• erb files are processed via Erubi; by default, erb 'foo.txt' will look for a foo.txt.erb file. The plan's parameters will be passed to the erb file, but additional local variables can be specified with the parameters: option. You can specify a specific ERB template with source:.
• download fetches a file. source: is required.
• literal takes a Ruby string as data: and writes a file with the contents of that string out to disk.

All content entries support the following options:

• only_if: Takes a lambda |parameters| {}; if truthy, writes out the file.

The root of your Plan should also contain a _settings.rb file which will describe what parameters should be passed into the Plan. These parameters can be retrieved interrogatively or passed in as data.

• parameter declarations require a name (a Symbol) and a description (a String). They can take the following options:
  • postprocess: if interactively delivered, the string that comes out of HighLine will be run through the specified 1-arity Proc. The returned value will be stored in parameters as exposed to the runtime.

• A Git handler for the plan content type would be a nice way to expand Copypasta's usability.
• Parameter validation, both per-parameter and at a higher level (combinations of parameters). The proper answer here is probably to use something like dry-validation that can accept Procs.

After checking out the repo, run bin/setup to install dependencies. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/eropple/copypasta. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The gem is available as open source under the terms of the MIT License.

Everyone interacting in the Copypasta project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.