Allow downloading chromium in a directory outside node_modules

[rohit-gohri]

The problem

I am running percy snapshot in my CI pipeline and it currently downloads chromium everytime. I have tried setting PERCY_BROWSER_EXECUTABLE=true but that doesn't help because npm ci deletes node_modules at the start and for yarn we don't cache node_modules but the yarn cache folder (.yarn/cache for berry).

Environment

• Node version: 16
• @percy/cli version: 1.0.0-beta.76
• Version of Percy SDK you’re using:
• If needed, a build or snapshot ID:
• OS version: ubuntu
• Type of shell command-line [interface]: bash

Details

There should be a global directory for caching/downloading chromium for percy. Similar to how Cypress stores it's binaries in ~/.cache/Cypress and we can cache that separately from node_modules.

See cypress docs for more details: https://docs.cypress.io/guides/continuous-integration/introduction#Caching

Debug logs

First Build: https://github.com/rohit-gohri/redocusaurus/actions/runs/1975488916/attempts/1
Second Build: https://github.com/rohit-gohri/redocusaurus/runs/5526059529?check_suite_focus=true

Both of them have the logs

YN0000: │ @percy/core@npm:1.0.0-beta.76 STDOUT [percy] Downloading Chromium 885264...
  ➤ YN0000: │ @percy/core@npm:1.0.0-beta.76 STDOUT [percy] Successfully downloaded Chromium 885264

Code to reproduce issue

Github Workflow: https://github.com/rohit-gohri/redocusaurus/blob/56b2e916f385cdff14c5466f045370952c1f75d2/.github/workflows/e2e.yml

[colinrotherham]

For context, the Puppeteer v19.00 update moved the Chromium binary download location to ~/.cache/puppeteer (global) from the previous Puppeteer node_modules .local-chromium (local) location

Looks like Percy uses the previous .local-chromium location

cli/packages/core/src/install.js

Line 129 in bf55129

directory = path.resolve(url.fileURLToPath(import.meta.url), '../../.local-chromium'),

You might see incompatibilities between expected Chromium versions but you can let Percy use the new location:

Config file .percy.js

const { executablePath } = require('puppeteer')

module.exports = {
  discovery: {
    launchOptions: {
      executable: executablePath()
    }
  },
  version: 2
}