AI Refactor is an experimental tool to see how AI (specifically OpenAI's ChatGPT) can be used to help apply refactoring to code.

The goal is not that the AI decides what refactoring to do, but rather, given refactoring tasks specified by the human user, the AI can help identify which code to change and apply the relevant refactor.

This is based on the assumption that the LLM AIs are pretty good at identifying patterns.

The quality of results depend very much on the version of ChatGPT being used.

I have tested with both 3.5 and 4 and see significantly better performance with version 4.

Currently available:

• rspec_to_minitest_rails: convert RSpec specs to minitest tests in Rails apps
• generic: provide your own prompt for the AI and run against the input files

Converts RSpec tests to minitest tests for Rails test suites (ie generated minitest tests are actually ActiveSupport::TestCases).

The tool first runs the original RSpec spec file and then runs the generated minitest test file, and compares the output of both.

The comparison is simply the count of successful and failed tests but this is probably enough to determine if the conversion worked.

stephen$ OPENAI_API_KEY=my-key ai_refactor rspec_to_minitest_rails spec/models/my_thing_spec.rb -v
AI Refactor 1 files(s)/dir(s) '["spec/models/my_thing_spec.rb"]' with rspec_to_minitest_rails refactor
====================
Processing spec/models/my_thing_spec.rb...
[Run spec spec/models/my_thing_spec.rb... (bundle exec rspec spec/models/my_thing_spec.rb)]
Do you wish to overwrite test/models/my_thing_test.rb? (y/n)
y
[Converting spec/models/my_thing_spec.rb...]
[Generate AI output. Generation attempts left: 3]
[OpenAI finished, with reason 'stop'...]
[Used tokens: 1869]
[Converted spec/models/my_thing_spec.rb to test/models/my_thing_test.rb...]
[Run generated test file test/models/my_thing_test.rb (bundle exec rails test test/models/my_thing_test.rb)...]
[Done converting spec/models/my_thing_spec.rb to test/models/my_thing_test.rb...]
No differences found! Conversion worked!
Refactor succeeded on spec/models/my_thing_spec.rb

Done processing all files!

Applies the refactor specified by prompting the AI with the user supplied prompt. You must supply a prompt file with the -p option.

The output is written to stdout, or to a file with the --output option. If --output is used without a value it overwrites the input.

You can also output to a file using a template, --output-template to determine the output file name given a template string:

The template is used to create the output name, where the it can have substitutions, '[FILE]', '[NAME]', '[DIR]', '[REFACTOR]' & '[EXT]'.

Eg --output-template "[DIR]/[NAME]_[REFACTOR][EXT]"

eg for the input my_dir/my_class.rb

• [FILE]: my_class.rb
• [NAME]: my_class
• [DIR]: my_dir
• [REFACTOR]: generic
• [EXT]: .rb

Install the gem and add to the application's Gemfile by executing:

$ bundle add ai_refactor

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install ai_refactor

See ai_refactor --help for more information.

Usage: ai_refactor REFACTOR_TYPE INPUT_FILE_OR_DIR [options]

Where REFACTOR_TYPE is one of: ["rspec_to_minitest_rails", "generic"]

    -p, --prompt PROMPT_FILE         Specify path to a text file that contains the ChatGPT 'system' prompt.
    -c, --continue [MAX_MESSAGES]    If ChatGPT stops generating due to the maximum token count being reached, continue to generate more messages, until a stop condition or MAX_MESSAGES. MAX_MESSAGES defaults to 3
    -m, --model MODEL_NAME           Specify a ChatGPT model to use (default gpt-3.5-turbo).
        --temperature TEMP           Specify the temperature parameter for ChatGPT (default 0.7).
        --max-tokens MAX_TOKENS      Specify the max number of tokens of output ChatGPT can generate. Max will depend on the size of the prompt (default 1500)
    -t, --timeout SECONDS            Specify the max wait time for ChatGPT response.
    -v, --verbose                    Show extra output and progress info
    -d, --debug                      Show debugging output to help diagnose issues
    -h, --help                       Prints this help

For refactor type 'generic':
        --output [FILE]              Write output to file instead of stdout. If no path provided will overwrite input file (will prompt to overwrite existing files)
        --output-template TEMPLATE   Write outputs to files instead of stdout. The template is used to create the output name, where the it can have substitutions, '[FILE]', '[NAME]', '[DIR]', '[REFACTOR]' & '[EXT]'. Eg `[DIR]/[NAME]_[REFACTOR][EXT]` (will prompt to overwrite existing files)

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/stevegeek/ai_refactor.

The gem is available as open source under the terms of the MIT License.