use the test file path in the Babel only prop instead of a pattern

lib/babel.js

@@ -4,9 +4,10 @@ var resolveFrom = require('resolve-from');
 var createEspowerPlugin = require('babel-plugin-espower/create');
 
 var hasGenerators = parseInt(process.version.slice(1), 10) > 0;
+var path = process.argv[2];
 
 var options = {
-	only: /(test|test\-.+|test\/.+)\.js$/,
+	only: path,
 	blacklist: hasGenerators ? ['regenerator'] : [],
 	optional: hasGenerators ? ['asyncToGenerator'] : [],
 	plugins: [
@@ -24,6 +25,4 @@ try {
 	require('babel-core/register')(options);
 }
 
-var path = process.argv[2];
-
 require(path);

test/fixture/babel-hook-imported.js

@@ -0,0 +1 @@
+module.export = async () => {};

test/fixture/babel-hook.js

@@ -0,0 +1 @@
+import x from './babel-hook-imported';

test/test.js

@@ -859,3 +859,11 @@ test('change process.cwd() to a test\'s directory', function (t) {
 		t.end();
 	});
 });
+
+test('Babel require hook only applies to the test file', function (t) {
+	execCli('fixture/babel-hook.js', function (err) {
+		t.ok(err);
+		t.is(err.code, 1);
+		t.end();
+	});
+});