plymouth

(C) John Mair (banisterfiend) 2012

Start Pry in the context of a failed test

Warning BETA software: Please file an issue if you have any problems

plymouth is a gem to automatically start a Pry session when a test fails, putting you in the context of the failure. It currently supports Bacon, Minitest, and RSpec. Support for other testing libraries is (usually) trivial to add.

plymouth utilizes the powerful pry-exception_explorer gem.

plymouth currently only runs on MRI 1.9.2+ (including 1.9.3)

How to use:

After installing the gem, simply add the following line to your test suite:

require 'plymouth'

plymouth should auto-detect which testing library you're using, and 'just work' :)

Example: Intercept a failing test in RSpec

Inside the test file:

require 'plymouth'

describe Array do
  before do
    @array = [1]
  end

  it 'should be empty' do
    @array.empty?.should == true
  end
end

And here is the result of running the above test with the rspec executable:

Test failure: expected: true
     got: false (using ==)

Frame number: 0/14
Frame type: block

From: /Users/john/ruby/play/rspec_intercept.rb @ line 9:

     4:   before do
     5:     @array = [1]
     6:   end
     7: 
     8:   it 'should be empty' do
 =>  9:     @array.empty?.should == true
    10:   end
    11: end

[1] (pry) #<RSpec::Core::ExampleGroup::Nested_1>: 0> @array.size                                                                                                                           
=> 1
[2] (pry) #<RSpec::Core::ExampleGroup::Nested_1>: 0> edit --current
Waiting for Emacs...
[3] (pry) #<RSpec::Core::ExampleGroup::Nested_1>: 0> ^D
F

Failures:

  1) Array should be empty
     Failure/Error: @array.empty?.should == true
       expected: true
            got: false (using ==)
     # ./rspec_intercept.rb:9:in `block (2 levels) in <top (required)>'

Finished in 7.74 seconds
1 example, 1 failure

Failed examples:

rspec ./rspec_intercept.rb:8 # Array should be empty

Edit the failing test code in an editor

Notice the line edit --current from the example above. Entering this command will take you to the line in the test file where the failing test was defined. Once here you can modify the test code as you please. Note that the file will not be reloaded after editing is complete, instead any modifications you make will only take effect the next time you run the test suite.

Turning plymouth off mid-test

If you are inside an interactive session and do not want plymouth to intercept further failing tests you can enter the command plymouth-off. This will disable plymouth for the remainder of the test suite.

The 'USE_PLYMOUTH' Environment variable

To make it easier to run your test suite normally (without plymouth's intervention) a USE_PLYMOUTH environment variable can be defined. If the USE_PLYMOUTH environment variable is set to "false", "0", or "no" plymouth will not intercept test failures. If USE_PLYMOUTH is not defined at all, plymouth will be used by default.

Travis Compatibility

To prevent plymouth messing up testing on travis, add the following line to your .travis.yml file:

env: USE_PLYMOUTH="no"

Limitations

• Occasional (very rare) segfault on 1.9.3 (seems to work fine on 1.9.2). Please report all segfaults with a full backtrace!
• Only supports MRI.
• Currently limited to just Bacon, RSpec and Minitest. Support for more testing libraries will be added in the future.
• Only intercepts test failures, does not yet (generally) intercept test errors. Support for this will be added soon.
• Does not work with Bacon's should.raise and should.not.raise constructions.

Contact

Problems or questions contact me at github

License

(The MIT License)

Copyright (c) 2012 John Mair (banisterfiend)

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.