# 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: ```ruby 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`) ```ruby #!/usr/bin/env ruby ``` * Require the library ```ruby require 'rake/toolkit_program' ``` * Make your life easier ```ruby Program = Rake::ToolkitProgram ``` * Define your command tasks ```ruby 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 ```ruby Program.run(on_error: :exit_program!) if $0 == __FILE__ ``` * In the shell, prepare to run the program (UNIX/Linux systems only) ```console $ 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 ```console $ ./awesome_tool.rb help *** ./awesome_tool.rb Toolkit Program *** . . . ``` ## Usage Let's look at a short sample toolkit program -- put this in `awesome.rb`: ```ruby #!/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 foo help $ ./awesome.rb f ↳ ./awesome.rb foo $ ./awesome.rb foo ↳ ./awesome.rb foo -- $ ./awesome.rb foo -- --help --implement $ ./awesome.rb foo --i ↳ ./awesome.rb foo --implement $ ./awesome.rb foo --implement --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 `yield`s 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](https://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](./CONTRIBUTING.md).