---
title: Running Specs From Vim
teaser:
tags: news,web,vim,testing
author: Dan Croak
published_on: 2013-08-05
---

Test driven development thrives on a tight feedback loop. However, switching
from the editor to the shell to manually run specs is inefficient.

Tools such as `autotest` and `guard` run specs whenever a file gets saved.
Although an improvement over a manual workflow, those approaches often run
the suite when not needed and run too many or too few specs.

Enter [vim-rspec](https://github.com/thoughtbot/vim-rspec), a lightweight
vim plugin that runs specs directly from within vim with the press of a key.

It exposes methods such as `RunNearestSpec()`, `RunCurrentSpecFile()`, and
`RunLastSpec()`, which can be bound to a key mapping of your choice. In
[thoughtbot/dotfiles](https://github.com/thoughtbot/dotfiles/blob/master/vimrc),
we bind those methods to `<Leader>s`, `<Leader>t`, and `<Leader>l`.

Cursor over any line within an RSpec spec like this:

    describe RecipientInterceptor do
      it 'overrides to/cc/bcc fields' do
        Mail.register_interceptor RecipientInterceptor.new(recipient_string)

        response = deliver_mail

        expect(response.to).to eq [recipient_string]
        expect(response.cc).to eq []
        expect(response.bcc).to eq []
      end
    end

Type `<Leader>s`:

    rspec spec/recipient_interceptor_spec.rb:4
    Run options: include
    {:locations=>{"spec/recipient_interceptor_spec.rb"=>[4]}}
    .

    Finished in 0.03059 seconds
    1 example, 0 failures

The screen is overtaken by a shell that runs just that focused spec. Developers
using tmux with vim-rspec and tslime sometimes send the output to a nearby
shell so the code and spec output display on the screen at the same time.

Feeling good that this new spec passes, run the whole file's specs with
`<Leader>t` to make sure the class's entire functionality is still intact:

    rspec spec/recipient_interceptor_spec.rb
    ......

    Finished in 0.17752 seconds
    6 examples, 0 failures

Red, green, refactor. From within the application's or library's code:

    def delivering_email(message)
      add_custom_headers message
      add_subject_prefix message
      message.to = @recipients
      message.cc = []
      message.bcc = []
    end

Run `<Leader>l` without having to switch back to the spec:

    rspec spec/recipient_interceptor_spec.rb
    ......

    Finished in 0.17752 seconds
    6 examples, 0 failures

These tight feedback loops make <abbr title="Test Driven Development">TDD</abbr> easier by eliminating the switching cost between editor to the shell when running specs.

## What's next

If you found this useful, you might also enjoy:

* [Running Specs from Vim, Sent to tmux Via Tslime][tslime]
* [Use RSpec.vim with tmux and Dispatch][dispatch]
* [Destroy All Software][das] for screencasts showing this and other
  productivity techniques with specs and Vim

[tslime]: https://thoughtbot.com/blog/running-specs-from-vim-sent-to-tmux-via-tslime
[dispatch]: https://thoughtbot.com/blog/use-rspec-vim-with-tmux-and-dispatch
[das]: https://www.destroyallsoftware.com/screencasts