This GitHub action allows you to measure and track TypeScript performance regressions in your projects by comparing tsc --diagnostics (or --extendedDiagnostics based on your configuration) outputs between the base branch and the current branch.

• base-branch: The branch that the actions should use to compare TSC performance (default: 'main').
• custom-command: Allows to override the default type check command. Your custom command should print either --diagnostics or --extendedDiagnostics output. (default: yarn tsc --noEmit --incremental false --diagnostics/--extendedDiagnostics).
• leave-comment: Indicates whether the action should leave a comment on a PR. Enabling this requires providing the github-token input (default: false).
• github-token: GitHub API token. Necessary to leave comments on your PRs.
• extended: Indicates whether the actions should use --extendedDiagnostics over --diagnostics (default: false).

You can add this action to your workflow file like this:

name: Check TypeScript Performance

on:
  pull_request:

jobs:
  check-performance:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v2
      - name: Use Node.js 16.x
        uses: actions/setup-node@v2
        with:
          node-version: 16.x
      - name: Install dependencies
        run: npm ci
      - name: TSC Diagnostics Diff
        uses: beerose/tsc-diff-action@v0.0.1
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          leave-comment: true

This example uses GITHUB_TOKEN to leave a comment on PRs with the diagnostics comparison.

Install the dependencies

$ npm install

Build the typescript and package it for distribution

$ npm run build && npm run package

Run the tests ✔️

$ npm test

 PASS  ./index.test.js
  ✓ throws invalid number (3ms)
  ✓ wait 500 ms (504ms)
  ✓ test runs (95ms)

...

Actions are run from GitHub repos so we will checkin the packed dist folder.

Then run ncc and push the results:

$ npm run package
$ git add dist
$ git commit -a -m "prod dependencies"
$ git push origin releases/v1

You can now validate the action by referencing ./ in a workflow in your repo (see test.yml)

uses: ./
with: ...

See the actions tab for runs of this action! 🚀