Tests: Unbreak test:cli due to unknown 'qunit' command

[Krinkle]

Follows-up 362e241, which removed 'npm link' from the 'test:cli'
script command.

Initially, I thought the reason the child processes can't find qunit is due to our use of execa.shell instead of regular execa. Specifically, execa.shell() spawns a process that starts with a new shell and no inherited environment variables. execa() on the other hand inherits environment variables like PATH by default, and it also has a preferLocal option that ensures node_modules/.bin is in thePATH even if you're running the tests without npm run .. (e.g. if you'd use bin/qunit test/cli/*.js directly).

Switching to execa() is non-trivial because it requires an array as input and there aren't built-in or trust-worthy modules that parse a command string into an array. Trying it with brute-force I realised the problem is actually that qunit isn't visible at all even in the original environment created by npm-run.

While npm-run does add node_modules/.bin, and bins from (dev)dependencies are indeed linked from there, the bins from the current package itself (qunit) are never linked in .bin.

So... keeping it simple and just string-replacing 'qunit' with 'bin/qunit', which also matches the way we invoke the cli from other commands in package.json already.

[trentmwillis]

Seems good to me. Looks like you'll need to make the same changes in

qunit/test/cli/watch.js

Lines 12 to 21 in 62374ea

	function execute( command ) {
	const cwd = process.cwd();
	process.chdir( path.join( __dirname, "fixtures" ) );
	const execution = exec( command, { stdio: [ null, null, null, "ipc" ] } );
	process.chdir( cwd );
	return execution;
	}

though. The function is roughly duplicated due to exec needing some different arguments to pipe output a specific way.

[trentmwillis]

Thanks!