# How to hack on RVM

## Try test suite on your rvm installation

Make sure you can successfully run the tests (you will need rvm already installed).

To run the tests:

    $ cd rvm-test
    $ gem install tf    # Install testing framework
    $ tf fast/*         # Run the short tests (those are run on travis)
    $ tf long/*         # Run the long set of tests, like installing rubies.
    $ tf --text long/*  # Same as above, but watch output

## Set up test installation of rvm

You need a test rvm install to run the test suite against:

    $ git clone https://github.com/rvm/rvm  # or your own github fork
    $ cd rvm
    $ rvm switch ~/path/to/rvm/test/install          # choose a path here
    $ ./install

This will create a test installation of rvm in
`~/path/to/rvm/test/install`, and as long as `$rvm_path` points to it,
this will be used when running the tests.  This means you can safely
break the test installation without risking breaking your main rvm
installation.

If you want to do manual testing on the CLI against this test installation,
you also need to do:

    $ rvm reload

To get back to using original rvm installation run:

    $ rvm switch ~/.rvm

## Hacking RVM via TDD (Test-Driven Development)

First write a test for the behaviour you expect.  For details on how
to write new tests, see [`rvm-test`'s
README.md](https://github.com/rvm/rvm-test/blob/master/README.md).
Then run the test:

    $ NOEXEC_DISABLE=1 tf --text rvm-test/fast/foo_comment_test.sh

It should fail.  Now repeat the following steps until the test passes:

    1. hack the changes in your rvm src tree
    2. run `./install`
    3. re-run the test (you can also manually test via rvm commands on the CLI)

Now `git commit`, `git push` to your GitHub fork, then issue a pull
request, and if it is accepted then your place in hacker heaven is
secured.

## Getting help

If you get stuck, you should ask on `#rvm-test` or `#rvm` on Freenode.