From d56dcf37d5c4216cf89bbe2d8735f4e633d61403 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        | 18 ++++++++++++++++++
 packages/jest-haste-map/src/crawlers/node.js   |  5 ++++-
 2 files changed, 22 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..7734a04b143e 100644
--- a/packages/jest-haste-map/src/crawlers/__tests__/node.test.js
+++ b/packages/jest-haste-map/src/crawlers/__tests__/node.test.js
@@ -59,6 +59,8 @@ jest.mock('fs', () => {
         setTimeout(() => callback(null, ['directory', 'tomato.js']), 0);
       } else if (dir === '/fruits/directory') {
         setTimeout(() => callback(null, ['strawberry.js']), 0);
+      } else if (dir == '/empty') {
+        setTimeout(() => callback(null, null), 0);
       }
     }),
     stat: jest.fn(stat),
@@ -217,4 +219,20 @@ 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)) {