Support JavaScript Playwright CLI paths

[dannote]

Summary

• launch JavaScript Playwright CLI paths through the Node executable
• use the same command resolution for version checks and run-driver
• cover CLI paths containing spaces with a self-contained Node fixture

This allows configurations such as assets/node_modules/playwright/cli.js to work on Windows, where JavaScript files cannot be passed directly to Port.open/2 as executables.

Testing

• mix format --check-formatted
• mix test test/playwright_ex/processes/port_transport_test.exs — 1 passed
• Hologram Windows browser suite — 6 passed using playwright/cli.js

mix credo --strict reports two pre-existing line-length findings in connection.ex and supervisor.ex; this change adds no Credo findings.

[ftes]

Danila, thanks for looking into this!
A few thoughts:

I'm not sure we should limit ourselves to node from PATH.
On Unix, we could keep supporting the shebang.

Or we could look at what the official playwright clients do.

Reference: Official Playwright clients

Explicit interpreter everywhere. Do not rely on shebang, but bundle matching Node executable and allow overriding through PLAYWRIGHT_NODEJS_PATH. No dependency on arbitrary node from PATH.

  # https://github.com/microsoft/playwright-python/blob/main/playwright/_impl/_driver.py#L28

if sys.platform == "win32":
  return (
    os.getenv("PLAYWRIGHT_NODEJS_PATH", str(driver_path / "node.exe")),
    cli_path,
  )
return (os.getenv("PLAYWRIGHT_NODEJS_PATH", str(driver_path / "node")), cli_path)

[ftes]

Restrict node resolution to Windows only?
Honor shebang on Unix.

Suggested change

	defp executable_command(executable, args) do
	if String.downcase(Path.extname(executable)) == ".js" do
	node = System.find_executable("node") || raise "Node.js executable not found on PATH"
	{node, [executable | args]}
	else
	{executable, args}
	end
	end
	defp executable_command(executable, args) do
	windows? = match?({:win32, _}, :os.type())
	javascript? = String.downcase(Path.extname(executable)) == ".js"
	if windows? and javascript? do
	node = System.find_executable("node") || raise "Node.js executable not found on PATH"
	{node, [executable | args]}
	else
	{executable, args}
	end
	end

[ftes]

I don't think this unit test is worth the complexity it adds.

If anything, we should expand the test matrix to also run on Windows.
Out of scope for this PR.

[dannote]

Thanks, good point. I’ve updated the PR to honor PLAYWRIGHT_NODEJS_PATH, keep shebang execution on Unix, and use node from PATH only as the Windows fallback.

PlaywrightEx doesn’t currently bundle Node, so the explicit override matches the official clients’ convention. Focused tests pass on Linux and Windows.

[ftes]

Why Path.expand executable here, but not in init?