Rake::ToolkitProgram

Create toolkit programs easily with Rake and OptionParser syntax. Bash completions and usage help are baked in.

Installation

Add this line to your application's Gemfile:

gem 'rake-toolkit_program'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rake-toolkit_program

Quickstart

• Shebang it up (in a file named awesome_tool.rb)

  #!/usr/bin/env ruby

• Require the library

  require 'rake/toolkit_program'

• Make your life easier

  Program = Rake::ToolkitProgram

• Define your command tasks

  Program.command_tasks do
    desc "Build it"
    task 'build' do
      # Ruby code here
    end
    
    desc "Test it"
    task 'test' => ['build'] do
      # Rake syntax ↑↑↑↑↑↑↑ for dependencies
      # Ruby code here
    end
  end

  You can use Program.args in your tasks to access the other arguments on the command line. For argument parsing integrated into the help provided by the program, see the use of Rake::Task(Rake::ToolkitProgram::TaskExt)#parse_args below.
• Wire the mainline

  Program.run(on_error: :exit_program!) if $0 == __FILE__

• In the shell, prepare to run the program (UNIX/Linux systems only)

  $ chmod +x awesome_tool.rb
  $ ./awesome_tool.rb --install-completions
  Completions installed in /home/rtweeks/.bashrc
  Source /home/rtweeks/.bash-complete/awesome_tool.rb-completions for immediate availability.
  $ source /home/rtweeks/.bash-complete/awesome_tool.rb-completions

• Ask for help

  $ ./awesome_tool.rb help
  
  *** ./awesome_tool.rb Toolkit Program ***
  
      .
      .
      .

Usage

Let's look at a short sample toolkit program -- put this in awesome.rb:

#!/usr/bin/env ruby
require 'rake/toolkit_program'
require 'ostruct'

ToolkitProgram = Rake::ToolkitProgram
ToolkitProgram.title = "My Awesome Toolkit of Awesome"

ToolkitProgram.command_tasks do
  desc <<-END_DESC.dedent
    Fooing myself
  
    I'm not sure what I'm doing, but I'm definitely fooing!
  END_DESC
  task :foo do
    a = ToolkitProgram.args
    puts "I'm fooed#{' on a ' if a.implement}#{a.implement}"
  end.parse_args(into: OpenStruct.new) do |parser, args|
    parser.no_positional_args!
    parser.on('-i', '--implement IMPLEMENT', 'An implement on which to be fooed') do |val|
      args.implement = val
    end
  end
end

if __FILE__ == $0
  ToolkitProgram.run(on_error: :exit_program!)
end

Make sure to chmod +x awesome.rb!

What does this support?

$ ./awesome.rb foo
I'm fooed
$ ./awesome.rb --help

*** My Awesome Toolkit of Awesome ***

Usage: ./awesome.rb COMMAND [OPTION ...]

Avaliable options vary depending on the command given. For details
of a particular command, use:

    ./awesome.rb help COMMAND

Commands:
     foo   Fooing myself
    help   Show a list of commands or details of one command

Use help COMMAND to get more help on a specific command.

$ ./awesome.rb help foo

*** My Awesome Toolkit of Awesome ***

Usage: ./awesome.rb foo [OPTION ...]

Fooing myself

I'm not sure what I'm doing, but I'm definitely fooing!

Options:
    -i, --implement IMPLEMENT        An implement on which to be fooed

$ ./awesome.rb --install-completions
Completions installed in /home/rtweeks/.bashrc
Source /home/rtweeks/.bash-complete/awesome.rb-completions for immediate availability.
$ source /home/rtweeks/.bash-complete/awesome.rb-completions
$ ./awesome.rb <tab><tab>
foo   help
$ ./awesome.rb f<tab>
↳ ./awesome.rb foo
$ ./awesome.rb foo <tab>
↳ ./awesome.rb foo --
$ ./awesome.rb foo --<tab><tab>
--help       --implement
$ ./awesome.rb foo --i<tab>
↳ ./awesome.rb foo --implement
$ ./awesome.rb foo --implement <tab><tab>
--help      awesome.rb
$ ./awesome.rb foo --implement spoon
I'm fooed on a spoon

Defining Toolkit Commands

Just define tasks in the block of Rake::ToolkitProgram.command_tasks with task (i.e. Rake::DSL#task). If desc is used to provide a description, the task will become visible in help and completions.

When a command task is initially defined, positional arguments to the command are available as an Array through Rake::ToolkitProgram.args.

Option Parsing

This gem extends Rake::Task with a #parse_args method that creates a Rake::ToolkitProgram::CommandOptionParser (derived from the standard library's OptionParser) and an argument accumulator and yields them to its block.

• The arguments accumulated through the Rake::ToolkitProgram::CommandOptionParser are available to the task in Rake::ToolkitProgram.args, replacing the normal Array of positional arguments.
• Use the into: keyword of #parse_args to provide a custom argument accumulator object for the associated command. The default argument accumulator constructor can be defined with Rake::ToolkitProgram.default_parsed_args. Without either of these, the default accumulator is a Hash.
• Options defined using OptionParser#on (or any of the variants) will print in the help for the associated command.

Positional Arguments

Accessing positional arguments given after the command name depends on whether or not Rake::Task(Rake::ToolkitProgram::TaskExt)#parse_args has been called on the command task. If this method is not called, positional arguments will be an Array accessible through Rake::ToolkitProgram.args.

When Rake::Task(Rake::ToolkitProgram::TaskExt)#parse_args is used:

• Rake::ToolkitProgram::CommandOptionParser#capture_positionals can be used to define how positional arguments are accumulated.
  • If the argument accumulator is a Hash, the default (without calling this method) is to assign the Array of positional arguments to the nil key of the Hash.
  • For other types of accumulators, the positional arguments are only accessible if Rake::ToolkitProgram::CommandOptionParser#capture_positionals is used to define how they are captured.
  • If a block is given to this method, the block of the method will receive the Array of positional arguments. If it is passed an argument value, that value is used as the key under which to store the positional arguments if the argument accumulator is a Hash.
• Rake::ToolkitProgram::CommandOptionParser#expect_positional_cardinality can be used to set a rule for the count of positional arguments. This will affect the usage presented in the help for the associated command.
• Rake::ToolkitProgram::CommandOptionParser#map_positional_args may be used to transform (or otherwise process) positional arguments one at a time and in the context of options and/or arguments appearing earlier on the command line.

Convenience Methods

• Rake::Task(Rake::ToolkitProgram::TaskExt)#prohibit_args is a quick way, for commands that accept no options or positional arguments, to declare this so the help and bash completions reflect this. It is equivalent to using #parse_args and telling the parser parser.expect_positional_cardinality(0).

• Rake::ToolkitProgram::CommandOptionParser#no_positional_args! is a shortcut for calling #expect_positional_cardinality(0) on the same object.

• Rake::Task(Rake::ToolkitProgram::TaskExt)#invalid_args! and Rake::ToolkitProgram::CommandOptionParser#invalid_args! are convenient ways to raise Rake::ToolkitProgram::InvalidCommandLine with a message.

OptionParser in Rubies Before and After v2.4

The OptionParser class was extended in Ruby 2.4 to simplify capturing options into a Hash or other container implementing #[]= in a similar way. This gem supports that, but it means that behavior varies somewhat between the pre-2.4 era and the 2.4+ era. To have consistent behavior across that version change, the recommendation is to use a Struct, OpenStruct, or custom class to hold program options rather than Hash.

Development

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.

To run the tests, use rake, rake test, or rspec spec. Tests can only be run on systems that support Kernel#fork, as this is used to present a pristine and isolated environment for setting up the tool. If run using Ruby 2.3 or earlier, some tests will be pending because functionality expects Ruby 2.4's OptionParser.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/PayTrace/rake-toolkit_program. For further details on contributing, see CONTRIBUTING.md.