Contents

require "dependency_bundle/version"

class DependencyBundle
  DependencyNotProvided = Class.new(StandardError)
  OverrideAttempted     = Class.new(StandardError)

  def initialize(&blk)
    set :env, ENV
    set :stdin, STDIN
    set :stdout, STDOUT
    set :stderr, STDERR

    instance_exec(&blk) if block_given?
  end

  def set(name, value)
    if respond_to?(name)
      raise(OverrideAttempted, "You can't override `:#{name}` on #{inspect}, since it already responds to `:#{name}`. If you're seeing this because you tried to override a dependency, please don't. DependencyBundle doesn't allow that because of the misery it would introduce into debugging (your logger or http client changing between constructors is just asking for trouble). If you didn't try to override a dependency, and there's just a pre-existing Ruby method that happens to be named the same as the key you're using, I'm sorry. Please register your dependency with a different key.")
    else
      define_singleton_method(name) { value }
    end
  end

  def verify_dependencies!(*names)
    raise(ArgumentError, "##{__method__} expects names of dependencies to be passed") if names.empty?

    not_found_names = names.reject(&method(:respond_to?))

    raise(DependencyNotProvided, "#{not_found_names} not set") if not_found_names.any?

    true
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
dependency_bundle-0.1.0	lib/dependency_bundle.rb