nix-playwright

# Playwright e2e under Nix For projects that already have a Playwright e2e suite (typically under `tests/`) and need it to run locally on NixOS / pure-Nix hosts, where Playwright's bundled Chromium download depends on `apt-get` + `sudo`. GitHub Actions CI is left untouched — apt-provided Chromium on Ubuntu runners is cheaper than spinning up a Nix devshell. This skill is for **local** runs (and Nix-based CI like Vira); GHA continues to use its own apt path. ## Add a `nixpkgs-latest` flake input In top-level `flake.nix`, add an independent pin so the Playwright rev moves on its own cadence (decoupled from the main `nixpkgs` your build uses): ```nix inputs.nixpkgs-latest.url = "github:nixos/nixpkgs/nixpkgs-unstable"; ``` ## `tests/shell.nix` Self-contained. Reads the parent flake's lock to resolve `nixpkgs-latest` without needing a flake context: ```nix let lock = builtins.fromJSON (builtins.readFile ../flake.lock); nixpkgsLocked = lock.nodes.nixpkgs-latest.locked; pkgs = import (builtins.fetchTree { type = "github"; inherit (nixpkgsLocked) owner repo rev narHash; }) { }; in pkgs.mkShell { packages = [ pkgs.nodejs ]; PLAYWRIGHT_BROWSERS_PATH = "${pkgs.playwright-driver.browsers}"; PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD = "1"; } ``` ## Justfile recipe ```just e2e: nix-shell tests/shell.nix --run "cd tests && { [ -d node_modules ] || npm ci; } && npm test" ``` ## Critical version constraint `pkgs.playwright-driver` version must match the `playwright` version in `tests/package.json`. Drift raises **"browser revision X not found at <PLAYWRIGHT_BROWSERS_PATH>"** at launch. Bump both together: 1. `nix flake update nixpkgs-latest` 2. Match `playwright` in `tests/package.json` to the new driver version 3. `npm install` in `tests/` to regenerate the lockfile ## Reference Pattern extracted from [emanote#660](https://github.com/srid/emanote/pull/660).