Bail

What

A miniscule DSL to write guard clauses. Also to ask some basic questions of my types when I get curious.

Why

I was finding my methods were collecting a top layer of IF/ELSE statements that got harder to read and maintain.

How

Sweet sexy voodoo magic.

---

A basic un-sugared guard looks something like this:

  Bail.when(:any, :of, :these, :things) {|item| item.nil?}

So you pass in an enumerator (defaults are the Enumerable module methods), any number of arguments, and a block for the condition test.

Super easy and super cheezy.

There are more specialized versions that do not require a block:
These are really just lightly sugared wrappers around Enumerable methods...

  Bail.when_any(condition, *objects)
  Bail.when_all(condition, *objects)
  Bail.when_one(condition, *objects)
  Bail.when_none(condition, *objects)

Why would you care?

To understand the why of this gem you can ask yourself this question:
Do I prefer to read this:

  [:one, :of, :these, :things].any? {|x| nil?}

or this:

  Bail.when_any(:nil, :one, :of, :these, :things)

to be honest I would prefer a fluent approach:

  Bail.when_any(:one, :of, :these, :things).are(:nil)

let's call that version 2.

Example Usage

Bail will usually live at the top of your methods.

  # Assuming that Bail.raise_on_error = false
  def some_method(that, takes, arguments)
    return if Bail.when(:nil, that, takes, arguments)
    return if Bail.when_none({:is_a, String}, that, takes, arguments)

    # I will use it for type discovery instead of blindly asking it to quack
    # i.e. I know I want the takes variable to be an Integer but I get it as a String sometimes...
    if Bail.when_any({:is_a: String}, takes)
      Logger.debug("you are passing in `takes` to `some_method` as a String from somewhere...")
      takes = takes.to_i
    end
  end

Installation

Add this line to your application's Gemfile:

gem 'bail'

And then execute:

$ bundle

Or install it yourself as:

$ gem install bail

Usage

TODO: Write usage instructions here

Contributing

1. Fork it ( http://github.com//bail/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request