reject test runs when forks exit with an unexpected signal

lib/fork.js

@@ -78,11 +78,15 @@ module.exports = function (file, opts) {
 			send(ps, 'teardown');
 		});
 
-		ps.on('exit', function (code) {
+		ps.on('exit', function (code, signal) {
 			if (code > 0) {
 				return reject(new AvaError(relFile + ' exited with a non-zero exit code: ' + code));
 			}
 
+			if (code === null && signal) {
+				return reject(new AvaError(relFile + ' exited due to ' + signal));
+			}
+
 			if (results) {
 				resolve(results);
 			} else {

test/fork.js

@@ -76,6 +76,18 @@ test('rejects promise if the process exits without results', function (t) {
 		});
 });
 
+test('rejects promise if the process is killed', function (t) {
+	var forked = fork(fixture('es2015.js'));
+	return forked
+		.on('stats', function () {
+			this.kill('SIGKILL');
+		})
+		.catch(function (err) {
+			t.is(err.name, 'AvaError');
+			t.is(err.message, path.join('test', 'fixture', 'es2015.js') + ' exited due to SIGKILL');
+		});
+});
+
 test('fake timers do not break duration', function (t) {
 	fork(fixture('fake-timers.js'))
 		.run({})