From a432e4be2a48bff16fd1da9182f8005cd808d3b5 Mon Sep 17 00:00:00 2001
From: Emilien Muraton <emilien.muraton@gmail.com>
Date: Thu, 26 Jul 2018 10:00:47 +0100
Subject: [PATCH] stop search if  is undefined

---
 .../src/crawlers/__tests__/node.test.js          | 16 ++++++++++++++++
 packages/jest-haste-map/src/crawlers/node.js     |  5 ++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/packages/jest-haste-map/src/crawlers/__tests__/node.test.js b/packages/jest-haste-map/src/crawlers/__tests__/node.test.js
index 64362a1d0515..3c93a83566bf 100644
--- a/packages/jest-haste-map/src/crawlers/__tests__/node.test.js
+++ b/packages/jest-haste-map/src/crawlers/__tests__/node.test.js
@@ -217,4 +217,20 @@ describe('node crawler', () => {
       expect(data.files).toEqual({});
     });
   });
+
+  it('completes with undefined names', () => {
+    process.platform = 'win32';
+
+    nodeCrawl = require('../node');
+
+    const files = Object.create(null);
+    return nodeCrawl({
+      data: {files},
+      extensions: ['js'],
+      ignore: pearMatcher,
+      roots: ['/empty'],
+    }).then(data => {
+      expect(data.files).toEqual({});
+    });
+  });
 });
diff --git a/packages/jest-haste-map/src/crawlers/node.js b/packages/jest-haste-map/src/crawlers/node.js
index 17ce3452e757..004dd46f23a1 100644
--- a/packages/jest-haste-map/src/crawlers/node.js
+++ b/packages/jest-haste-map/src/crawlers/node.js
@@ -30,7 +30,10 @@ function find(
     activeCalls++;
     fs.readdir(directory, (err, names) => {
       activeCalls--;
-
+      if (!names) {
+        callback(result);
+        return;
+      }
       names.forEach(file => {
         file = path.join(directory, file);
         if (ignore(file)) {