feat(deps): add native Fedora Linux support

[CybLow]

Summary

This PR adds native Fedora Linux support to Playwright. Currently, Playwright only supports Debian/Ubuntu-based distributions — running on Fedora fails because:

• install-deps hardcodes apt-get (Fedora uses dnf)
• No Fedora RPM package mappings exist
• Error messages reference apt-get install instead of dnf install

Fedora is the 3rd most popular Linux distribution and the upstream for RHEL/CentOS/Rocky/Alma. This PR makes Chromium and Firefox work natively on Fedora with zero workarounds.

What this PR does

Platform detection (hostPlatform.ts, linuxUtils.ts):

• Detects Fedora via /etc/os-release → fedora-x64 / fedora-arm64
• Adds id_like field to os-release parsing (for future RHEL-family detection)
• Versionless platform string (Fedora packages are stable across versions 39–43+, and versions have short 13-month lifecycles unlike Ubuntu LTS)
• isOfficiallySupportedPlatform: false (browsers are Ubuntu-built binaries)

Package management (dependencies.ts):

• getLinuxPackageManager() helper: returns 'dnf' for Fedora, 'apt' otherwise
• installDependenciesLinux(): uses dnf install -y --skip-unavailable on Fedora
• validateDependenciesLinux(): shows dnf install in error messages
• Validation correctly separates compat-layer libs from regular missing deps:
  • Compat-only missing → warns with install-deps guidance (doesn't block Chromium/Firefox)
  • dlopen-only libs (e.g. libx264.so from RPM Fusion) → warns, doesn't block browser launch
  • Truly required ldd deps missing → throws with correct dnf package suggestions

Browser downloads (index.ts):

• Adds fedora-x64 and fedora-arm64 to all DOWNLOAD_PATHS records
• Chromium/Firefox: reuses Ubuntu 24.04 builds (these binaries work cross-distro)
• WebKit: also uses Ubuntu 24.04 builds (see WebKit section below)

Native dependencies (nativeDeps.ts):

• Complete fedora-x64 entry with correct Fedora RPM package names for tools, chromium, firefox, webkit
• 70+ lib2package mappings (.so names → Fedora RPM package names)
• Tool deps include curl, binutils, tar, findutils (needed by compat layer)
• fedora-arm64 spread variant

WebKit on Fedora — discussion needed

WebKit binaries are compiled on Ubuntu 24.04, which means they link against Ubuntu's library versions. On Fedora, several libraries have ABI-incompatible versions:

Library	Ubuntu 24.04 (what WebKit expects)	Fedora 43 (what system has)
libjpeg	libjpeg.so.8 (LIBJPEG_8.0 ABI)	libjpeg.so.62 (LIBJPEG_6.2 ABI)
ICU	libicudata.so.74 (ICU 74)	libicudata.so.75+ (ICU 75–77)
libjxl	libjxl.so.0.8 (soversion 0.8)	libjxl.so.0.11 (soversion 0.11)

This cannot be fixed in TypeScript — it's baked into the compiled C++ binary. This PR includes a compatibility layer (fedoraCompat.ts) that:

1. Downloads Ubuntu 24.04's libjpeg-turbo8 .deb → extracts libjpeg.so.8 with LIBJPEG_8.0 symbols (HTTPS, architecture-aware)
2. Downloads Ubuntu 24.04's libicu74 .deb → extracts ICU 74 libraries
3. Creates a libjxl.so.0.8 symlink → system's libjxl.so.0.11
4. Patches WebKit MiniBrowser wrapper scripts to include compat libs in LD_LIBRARY_PATH
5. Compat libraries auto-install during both playwright install-deps and playwright install webkit
6. Idempotent wrapper patching via dedicated # playwright-fedora-compat-patched marker (works regardless of custom PLAYWRIGHT_COMPAT_DIR)
7. Full error handling with warnings on all failure paths

All compat libraries are installed to ~/.local/lib/playwright-compat/ (user-scoped, non-invasive).

I understand this compat layer may not align with the project's architecture and the team may prefer a different approach. Possible alternatives:

1. Remove WebKit support for Fedora entirely — set download path to undefined, ship Chromium + Firefox only. Clean and honest.
2. Add Fedora to the WebKit build matrix — build webkit-fedora.zip on Fedora CI, which would eliminate all ABI issues. This is the proper long-term fix.
3. Keep the compat layer — it works and is tested, but adds complexity.

I'm happy to strip fedoraCompat.ts and remove WebKit support from this PR if the team prefers option 1, and then open a follow-up issue requesting Fedora WebKit builds.

What this gives Fedora users

# These work natively:
npx playwright install-deps        # uses dnf, installs correct RPM packages
npx playwright install chromium     # downloads and works
npx playwright install firefox      # downloads and works

# Chromium and Firefox API works:
const { chromium, firefox } = require('playwright');
const browser = await chromium.launch();  // works
const browser = await firefox.launch();   // works
const browser = await webkit.launch();    // works (via compat layer)

Design decisions

Decision	Choice	Rationale
Platform string	fedora-x64 (versionless)	Fedora packages are stable across versions, and versions have short 13-month lifecycles
Officially supported	false	Browsers are Ubuntu-built binaries
Package manager detection	Check platform string prefix	Simpler and more reliable than probing filesystem
RHEL/CentOS/Rocky/Alma	Not included	Different package versions — separate contribution if needed

Testing

Tested on a clean Fedora 43 Docker container (no pre-installed dev tools, no env var workarounds):

• Platform detected as fedora-x64
• install-deps uses dnf with correct packages
• Chromium: 22 API tests passed (launch, navigate, JS eval, DOM, screenshots, viewport, cookies, network interception, locators, video, tracing, HAR, device emulation, etc.)
• Firefox: 18 API tests passed
• WebKit: 18 API tests passed (via compat layer)
• CLI: 9 tests passed (screenshots, PDF generation, version, clear-cache)
• Total: 70 passed, 0 failed

See also: playwright-fedora — standalone Fedora integration testing repo with Docker-based test suite.

Test plan

• npm run flint passes (ESLint + tsc clean, doclint failure is pre-existing — requires browser binaries installed)
• Test on Fedora 43 Docker: npx playwright install-deps uses dnf
• Test on Fedora 43 Docker: Chromium launch + full API test suite
• Test on Fedora 43 Docker: Firefox launch + full API test suite
• Test on Fedora 43 Docker: WebKit launch + full API test suite (via compat layer)
• Test on Fedora 43 Docker: CLI commands (screenshots, PDF, version)
• Verify TypeScript Record<HostPlatform, ...> completeness (all DOWNLOAD_PATHS include fedora entries)
• No regressions on Ubuntu/Debian (no code paths changed for existing platforms)

[yury-s]

This is out of scope at the moment.

[CybLow]

This is out of scope at the moment.

what part is out of scope exactly? Fedora are a huge developper base os. It's the support in general, or specifically the WebKit compat layer?
Asking because Chromium and Firefox just work, no hacks involved. The only messy part is WebKit, and that’s entirely a CI problem (Ubuntu-built binaries + ABI mismatch). I’m happy to strip that out completely and keep this PR to Chromium + Firefox only.
Also worth noting Fedora is upstream of RHEL, Rocky, and Alma. Right now those users run npx playwright install-deps and get told to run apt-get install. That command doesn’t even exist on their system.
If dropping WebKit makes this mergeable, I can have a clean PR up quickly.