files

Files

a simple DSL for creating temporary files and directories

Ever want to create a whole bunch of files at once? Like when you're writing tests for a tool that processes files? The Files gem lets you cleanly specify those files and their contents inside your test code, instead of forcing you to create a fixture directory and check it in to your repo. It puts them in a temporary directory and cleans up when your test is done.

Usage (mixin mode)

The mixin mode is a fairly clean API, suitable for use in unit tests. After include Files you can call file or dir to make a temporary file or directory; it'll put them into a new temp dir that is removed on process exit. It also saves a reference to this directory inside an instance variable named @files (so don't use that name for your own instance variables).

require "files"
include Files

file "hello.txt"     # creates file "hello.txt" containing "contents of hello.txt"

dir "web" do              # creates directory "web"
  file "snippet.html",    # creates file "web/snippet.html"...
    "<h1>Fix this!</h1>"  # ...containing "<h1>Fix this!</h1>"
  dir "img" do            # creates directory "web/img"
    file File.new("data/hello.png")            # containing a copy of hello.png
    file "hi.png", File.new("data/hello.png")  # and a copy of hello.png named hi.png
  end
end

@files.root           # returns the path to the temporary directory, creating it if necessary

Usage (bare function mode)

In bare function mode, you call the Files method, which doesn't pollute the current object with a @files instance variable. It returns a string with the path to the root temp dir that you can use later.

require "files"

temp_dir = Files do         # creates a temporary directory inside Dir.tmpdir
  file "hello.txt"          # creates file "hello.txt" containing "contents of hello.txt"
  dir "web" do              # creates directory "web"
    file "snippet.html",    # creates file "web/snippet.html"...
      "<h1>Fix this!</h1>"  # ...containing "<h1>Fix this!</h1>"
    dir "img" do            # creates directory "web/img"
      file File.new("data/hello.png")            # containing a copy of hello.png
      file "hi.png", File.new("data/hello.png")  # and a copy of hello.png named hi.png
    end
  end
end                         # "Files" returns a string with the path to the directory

src = '/path/to/some/data' # use '/path/to/some/data/.' to only copy contents of data folder, not data folder itself.

# creates a folder called 'target/$timestamp' relative to pwd
dir = Files.create :path => "target" do
    dir "foo", :src => src do # creates 'target/$timestamp/foo', and copies src into foo [but should it copy the dir or the contents?]
    end
end

see test/files_test.rb for more usage examples

Details

• the directory will be removed at exit

  • unless you pass :remove => false

• the directory name is based on the name of the source file you called Files from

• if the first argument to file is a String, then a new file is made

  • the content of the new file is either a short, descriptive message, or whatever you passed as the second argument

• if the argument to file is a Ruby File object, then it copies the named file into the new location

• To copy another directory to one created by this module, specifying :src to dir method

  • [Not sure if this is implemented right... should it copy the dir or its contents?]

• the dir do block is executed in the scope of the Dir object, so it can't call methods on your object directly. Instead, set a temporary local variable, like this:

    my_cheese = cheese()
    dir do
      file "which_cheese.txt", my_cheese
    end
  

TODO

• take a hash or a YAML file or YAML string to specify the directory layout and contents
• emit a hash or a YAML file or string to serialize the directory layout and contents for later
• support symlinks (?)
• specify file write mode (?)
• play nice with FakeFS (possibly with a :fake option)
• global/default :remove option

Credits

Written by Alex Chaffee http://alexchaffee.com mailto:[e-mail] http://github.com/alexch @alexch

Patches by

• Seth Call

License [MIT]

Copyright (C) 2012 Alex Chaffee

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.