dot errors rspec custom formatter

I work with two terminals side by side, a wide one of the left for running and an 80 columns one on the right for editing. The left one often gets hidden behind a browser window but I can easily bring it back with a keyboard shortcut.

My Ruby coding is a long back and forth between those two terminals, write some code on the right, run one or more specs on the left, read the error messages, fix on the right... It happens without clicking, only keyboard interactions.

I wanted to navigate immediately from an error to its location in its spec file. At first, I was thinking about letting the click on the spec/nasty_spec.rb:66trigger something but it would kill the "only keyboard interactions" joy.

I came up with a custom Rspec formatter.

# ~/.bash/rspec_dot_errors_formatter.rb

class DotErrorsFormatter

  RSpec::Core::Formatters.register self, :dump_failures

  def initialize(output)

    @output = output

  def dump_failures(notification) # as registered above

    notification.failure_notifications.each do |fn|
      m = fn.formatted_backtrace.first.match(/\A([^:]+_spec\.rb:\d+):in /)
      @output << m[1] << "\n"
No magic here, it simply produces a list of lines looking like:

I placed this rspec_dot_errors_formatter.rb file in my .bash/ directory and made sure my usual bxs alias includes this formatter when calling rspec:

alias bxs="bundle exec rspec \
    --require ~/.bash/rspec_dot_errors_formatter.rb \
    --format DotErrorsFormatter --out .errors \
    --format d"

Note how I require the source file containing the custom formatter, then ask for it via --format, ensure its output is piped to .errors thanks to --out and then fall back to my default formatter d (for "documentation") followed by nothing. The --out is only for the preceding --format.

When running my specs, it will write down in a file named .errors the error locations in the specs.

I combined that with my ListFiles() function in Vim and get my list of error location beween my list of open buffers and of recently opened files:

I can now navigate to the "== .errors" section and jump directly to the error in the spec.

The next refinement will probably consist in mining each failure stacktrace for relevant file locations in the source itself, not in the spec source.

2016-12-05 update: let the ~/.bash/rspec_dot_errors_formatter.rb script add to .errors only the first _spec.rb files it encounters in the backtraces