Use advanced serialization (when available) for test worker communication

Author: novemberborn

lib/fork.js

@@ -14,6 +14,12 @@ const AVA_PATH = path.resolve(__dirname, '..');
 
 const workerPath = require.resolve('./worker/subprocess');
 
+const useAdvanced = process.versions.node >= '12.16.0';
+// FIXME: Fix this in api.js or cli.js.
+const serializeOptions = useAdvanced ?
+	options => JSON.parse(JSON.stringify(options)) : // Use JSON serialization to remove non-clonable values.
+	options => options;
+
 module.exports = (file, options, execArgv = process.execArgv) => {
 	let finished = false;
 
@@ -34,7 +40,8 @@ module.exports = (file, options, execArgv = process.execArgv) => {
 		cwd: options.projectDir,
 		silent: true,
 		env: {NODE_ENV: 'test', ...process.env, ...options.environmentVariables, AVA_PATH},
-		execArgv
+		execArgv,
+		serialization: useAdvanced ? 'advanced' : 'json'
 	});
 
 	subprocess.stdout.on('data', chunk => {
@@ -66,7 +73,7 @@ module.exports = (file, options, execArgv = process.execArgv) => {
 			}
 
 			if (message.ava.type === 'ready-for-options') {
-				send({type: 'options', options});
+				send({type: 'options', options: serializeOptions(options)});
 				return;
 			}