TCR workshop

Information and instructions for trying the TCR workflow (test && commit || revert) as first described here.

This repository contains scripts for Python, Java, NetCore, Elixir, Ruby and Rust examples, each of them in their own folders.

Here you can find the slides used for a workshop facilitated with Joe Bew in Stockholm.

There is also a generic folder with scripts that could be easily adapted to your specific language (/tcr-generic).

Prerequisites

• You need Git installed.
• A basic test running (see "How to set up a basic test" section if you're having problems).

How to set up a basic test

Here you can find lots of templates for different languages. Plus, you have tcr-python, tcr-java, tcr-csharp, tcr-elixir, tcr-rust, tcr-ruby and tcr-go folders ready in this repo.

IDE configuration

• VERY IMPORTANT: Disable the "Auto-save".
  • IntelliJ: http://thehunk.blogspot.com/2015/07/disable-auto-save-in-jetbrains-ide.html
• Be sure the file is being automatically refreshed (to see the file reverted when the tests fail).
  • VS Studio Code. Several options:
    • enable "experimental file watcher" from File -> Settings. Unfortunately, it doesn't seem to work "too well".
    • Reload Window: Ctl + 5
    • Or configure a shortcut for "File revert" (e.g. "Alt + Shift + r")

How to configure your environment for TCR

There are several options for configuring your local environment so that you code gets automatically committed or reverted:

• Option 1: IDE
  • Use a plugin on your favourite IDE.
    • For example, in IntelliJ you have "Limited WIP": https://github.com/dkandalov/limited-wip (though, to be honest, it didn't work too well for me...).
    • In VS Studio you could play with "Watched Path Autoexec": https://marketplace.visualstudio.com/items?itemName=hexix.watched-path-autoexec
• Option 2: scripts
  • A more agnostic solution: use the scripts included under the folder /scripts of each java/python/generic folder of this repo (or create your own). The scripts are based on these.
  • You can either:
    • install inotifywait or something similar depending on your OS:
      • E.g. in Ubuntu run sudo apt-get install inotify-tools
      • On Mac OS X: https://superuser.com/questions/371354/inotifywait-alternative-command-for-mac
      • On Windows, one option is to use Cygwin and run the Linux scripts.
      • If you use something different to inotifywait, modify your watch.sh file.
    • install the watch utility (it exists in both Linux and Mac OSX), and use the watch-generic.sh script included under the folder tcr-generic
  • To run the scripts, go to your specific folder (e.g. tcr-python), and run ./watch.sh or watch-generic.sh (if using the generic one with watch)

Proposed exercise

• You can try the TCR workflow with the Fibonacci kata, included here
• Another simple exercise to practice it is the substring kata

Bonus track

• There is a variant where, when failing the tests, before reverting, you stash and print your changes. That would allow you to check what was the difference between last time it was green and now. Here you have the proposal and the scripts: https://rachelcarmena.github.io/2018/11/13/test-driven-programming-workflows.html
• Another more relaxed variant here: https://medium.com/@tdeniffel/tcr-variants-test-commit-revert-bf6bd84b17d3

How to squash

• Since the TCR scripts will be automatically commiting, you should first squash you commits before pushing to the remote branch.
• Here a reminder about how to do it: https://www.internalpointers.com/post/squash-commits-into-one-git

Scripts examples for JavaScript

https://medium.com/@itortv/i-implemented-the-mars-rover-kata-through-tcr-test-commit-revert-and-these-are-my-7e11c40983a6

Interesting links

• Reference from Kent Beck: https://increment.com/testing/testing-the-boundaries-of-collaboration/
• https://medium.com/@kentbeck_7670/test-commit-revert-870bbd756864
• https://medium.com/@kentbeck_7670/limbo-on-the-cheap-e4cfae840330
• https://rachelcarmena.github.io/2018/11/13/test-driven-programming-workflows.html
• https://medium.com/@barlindhaug/how-to-test-commit-revert-e850cd6e2520
• https://blog.adrianbolboaca.ro/2013/03/taking-baby-steps/
• https://medium.com/@tdeniffel/test-commit-revert-questions-answered-ddf012a1af97
• https://medium.com/@tdeniffel/all-downsides-and-open-questions-of-tcr-885bfee27146
• https://www.davidtanzer.net/david's%20blog/2019/03/06/test-commit-revert.html
• https://medium.com/@itortv/i-implemented-the-mars-rover-kata-through-tcr-test-commit-revert-and-these-are-my-7e11c40983a6

Screencasts

• Kent Beck: Understanding Legacy Code with TCR (test && commit || revert) - Video duration: 12 min.
• Kent Beck: substring, TCR style