locust

"It's git diff --stat on steroids!" - @scottmilliken

What is Locust?

Locust reduces turnaround time on code reviews.

It can take a lot of effort for a reviewer to relate the line-by-line changes in a patch to their mental model of the code base. This is a consistent impediment to fast responses on code reviews.

Locust provides a semantic layer on top of git diff. Where git diff describes changes in terms of the lines in the code base, Locust summarizes changes by the effect on modules, classes, and functions.

How does it work?

Locust is a command line tool, and you can invoke it as:

locust 22dd7fd6adf392bb29d13d10f10e7dbb1d97bfce c9813bd5871a9919551ccd917712135c40367c5c --format yaml

This produces the following output:

locust:
  - file: locust/ci_helpers/github.py
    changes:
      - name: generate_argument_parser
        type: function
        line: 11
        changed_lines: 9
        total_lines: 9
        children: []
      - name: helper_push
        type: function
        line: 22
        changed_lines: 13
        total_lines: 13
        children: []
      - name: helper_pr
        type: function
        line: 37
        changed_lines: 14
        total_lines: 14
        children: []
      - name: main
        type: function
        line: 53
        changed_lines: 29
        total_lines: 29
        children: []
refs:
  initial: 22dd7fd
  terminal: c9813bd

CI/CD

Locust is easy to use in CI/CD pipelines:

• Locust GitHub Action

Installation

Locust requires Python3 (specifically, it was written in Python3.8).

Install from PyPI

pip install bugout-locust

Install from source

Clone this repository and run from the project root:

python setup.py install

Docker

You can also use the Locust docker image:

docker pull bugout/locust

To run Locust using docker:

docker run -v $ABSOLUTE_PATH_TO_GIT_REPO:/usr/src/app bugout/locust -r /usr/src/app \
    $INITIAL_REVISION \
    $TERMINAL_REVISION \
    --format yaml

Output formats

Locust can produce output in many formats. The currently supported formats are:

1. JSON (--format json)

2. YAML (--format yaml)

3. HTML (--format html)

4. GitHub-flavored HTML, meant to be used with GitHub styles (--format html-github)

Contributing

Running tests

Make sure to clone simiotics/locust-test-cases repo to your machine.

Run:

git -c <path to locust-test-cases repo> fetch origin

Then, from the root of this repo:

LOCUST_TESTCASES_DIR=<path to locust-test-cases repo> ./test.sh