set process.cwd() to a test's directory

lib/fork.js

@@ -2,6 +2,7 @@
 
 var childProcess = require('child_process');
 var Promise = require('bluebird');
+var dirname = require('path').dirname;
 var join = require('path').join;
 
 module.exports = fork;
@@ -14,7 +15,12 @@ function fork(args) {
 	var babel = join(__dirname, 'babel.js');
 	var file = args[0];
 
-	var ps = childProcess.fork(babel, args, {silent: true});
+	var options = {
+		silent: true,
+		cwd: dirname(file)
+	};
+
+	var ps = childProcess.fork(babel, args, options);
 
 	var promise = new Promise(function (resolve, reject) {
 		ps.on('results', function (results) {

test/fixture/process-cwd.js

@@ -0,0 +1 @@
+console.log(process.cwd());

test/test.js

@@ -3,6 +3,7 @@ var childProcess = require('child_process');
 var Promise = require('bluebird');
 var figures = require('figures');
 var test = require('tape');
+var join = require('path').join;
 var Runner = require('../lib/runner');
 var ava = require('../lib/test');
 
@@ -850,3 +851,11 @@ test('power-assert support', function (t) {
 		t.true((/t\.ok\(a === 'bar'\)\s*\n\s+\|\s*\n\s+"foo"/m).test(stderr));
 	});
 });
+
+test('change process.cwd() to a test\'s directory', function (t) {
+	execCli('fixture/process-cwd.js', function (err, stdout) {
+		t.ifError(err);
+		t.is(stdout.trim(), join(__dirname, 'fixture'));
+		t.end();
+	});
+});