Jest Performance Test Logger

A small custom reporter to optimize the worker count on your laptop, computer, containers, or servers. Log simple stats to a log.csv file in the root of the repo that is using the custom reporter. I thought logging to a csv file would be useful, if user wanted to keep info beyond the command line output, for analysis in a spreadsheet program.

Stats recorded: total tests, total suites, total time in seconds, max workers for the run

Installing & Usage with Jest

1. Install: npm i --save-dev jest-reporter-perf-stats

2. add the custom reporter to your jest.config.js

module.exports = {
  ...
  reporters: ['default', 'jest-reporter-perf-stats'],
  ...
};

3. Run the performance benchmark with the included script:
   ./node_modules/jest-reporter-perf-stats/perf.sh <maxWorkers> <number of iterations>

Example: ./node_modules/jest-reporter-perf-stats/perf.sh 1 1

4. View the results in log.csv, logging the following attributes:

• total tests in test run
• total suites in test run
• test run duration in seconds
• number of workers in test run

Contributing

PRs welcome!

Sanity check that reporter works:

1. Clone repo and install dependencies npm i
2. Run npm run test_one_worker
3. Ensure log.csv outputs correctly and CLI outputs something akin to:

Test Suites: 1 failed, 1 passed, 2 total
Tests:       2 failed, 2 skipped, 1 todo, 3 passed, 8 total
Snapshots:   0 total
Time:        0.815 s, estimated 1 s
Ran all test suites.
---------------
total time for run is 0.818 seconds for 1 maxWorkers.
Total tests: 8 Total suites: 2.
---------------