A file to define environment dependencies for applications
In a file named .dependencies
at the root of your project:
ruby: "~> 2.3", file: "Gemfile"
postgres: "~> 9.3"
python: "~> 2.7", file: "requirements.txt"
node: "~> 5.5", file: "package.json"
Take the line ruby: "~> 2.3", file: "Gemfile"
. Let's break it down.
ruby
is the name of the system-level software being dependend on by your program"~> 2.3"
defines the version constraint for theruby
dependency,~>
means "loose" which is equivalent to saying "I want any version including 9.3 and above but below 9.4".file
is an optional key that allows you to specify where the system-level dependency can find its own dependencies, and in Ruby programs usually document their dependencies using a BundlerGemfile
.