fix: unwrap ESM-style process polyfills in internal streams (fixes #539)

[smessie]

Summary

Some browser bundlers/polyfill setups expose the process/ polyfill as an ES module with a default export (i.e. { __esModule: true, default: <process> }). The internal streams code does const process = require('process/') and then uses process.nextTick(...), which throws in that scenario because the module namespace object has no nextTick.

This routes the internal process/ imports through a small shim that unwraps such ESM-style polyfills (returning the first candidate exposing nextTick) while leaving normal CommonJS polyfills untouched.

Fixes #539.
This PR follows a similar approach as #543.

Changes

• Add lib/internal/shims/process.js (generated from src/) that unwraps an ESM-default process/ polyfill, validating candidates via 'nextTick' in candidate, and falls back to the module as-is otherwise.
• Route the internal streams (destroy, duplexify, end-of-stream, from, pipeline, readable, writable) through the shim instead of require('process/') directly.
• Wired through the repo's build/replacement generation so both the source and generated outputs are consistent.

Tests

• Adds test/ours/test-process-shim.js verifying the shim resolves the real process object (with nextTick) when given an ESM-default-shaped polyfill, and returns a plain process-like object unchanged.
• npm test, npm run lint, npm run test:format, and the browserify bundle test all pass.

Context

This fix is currently carried as a patch-package patch in Comunica to make it work in the browser; upstreaming it here removes the need for the patch. See comunica/comunica#1724.

[smessie]

Any chance we can have a look at this @mcollina ?

[mcollina]

lgtm

[mcollina]

ci looks red

[smessie]

@mcollina This is because the CI still uses unsupported Node.js versions.

Run ./node_modules/.bin/playwright install firefox
You are running Node.js 16.20.2.
Playwright requires Node.js 18 or higher. 
Please update your version of Node.js.
Error: Process completed with exit code 1.

I've pushed a commit that updates the CI to the latest LTS versions.

[smessie]

Does this look good to you @mcollina or do you prefer another way to solve this CI problem?

[smessie]

Any chance we can get this merged @mcollina ?

[mcollina]

Unfortunately, we still needs to test 12, 14, 16, 18, 20 and 21.

[smessie]

The failing CI is not related to this PR, yet I pushed a commit that solves it. I dropped my previous commit such that it is testing against the old Node.js versions again.
The new commit updates the browser tests to Node.js 22 as playwright, used for these tests, no longer supports Node.js 16, so any other PR would face the same issue.

Does this suffice, @mcollina? If not, please be specific about the path you want to take. I’ll then determine if I still have the time to investigate this, or if I’ll have to abandon this effort.

[smessie]

Any word on this @mcollina ?

[smessie]

@mcollina I kept the old Node.js versions in the test matrices, as requested. Two extra commits were needed to get CI green.

1. ci: run browser tests on Node.js 22 (browsers.yml)

playwright is declared as ^1.21.1, so a fresh npm install in CI now resolves to 1.62.0, which requires Node.js 20 or higher. The Install Browser step aborted on Node.js 16 before any test ran. Only browsers.yml is bumped. node.yml and bundlers.yml keep testing Node.js 12 through 21.

2. fix: declare ajv explicitly so webpack bundling works on npm 6/7 (package.json)

webpack pulls in schema-utils@4, which depends on ajv-keywords@5 and its peer dependency ajv@^8.8.2. npm 6 and 7, shipped with Node.js 12 and 14, do not install peer dependencies, so ajv-keywords ends up hoisted next to the ajv@6 that eslint requires, and fails with:

[webpack-cli] Error: Cannot find module 'ajv/dist/compile/codegen'

That breaks npm run test:prepare webpack on those two versions. Declaring ajv@^8.8.2 hoists v8 to the root of the tree and nests eslint's v6 underneath it. npm 8 and later install the peer dependency already, so nothing changes there.

This one is not caused by this PR. The same failure reproduces on main with Node.js 14 and npm 6, so the ubuntu-latest, 12.x, webpack and ubuntu-latest, 14.x, webpack legs of the bundlers workflow were already red.

Since workflow runs here need maintainer approval, I verified everything on my fork:

• Bundlers before the ajv commit, 42/44, both webpack legs on Node.js 12 and 14 failing: https://github.com/smessie/readable-stream/actions/runs/31486989796
• Bundlers after, 44/44: https://github.com/smessie/readable-stream/actions/runs/31492474993
• Browsers on Node.js 22, 40/40: https://github.com/smessie/readable-stream/actions/runs/31492474977

Full matrix on the final commit is green: Browsers 40/40, Bundlers 44/44, Node.js 14/14, Lint 1/1.

Happy to split the ajv change into a separate PR if you prefer to keep this one focused on the process polyfill fix.