From d2d7a2330c247c9a72bf910bdc5266bbed401e2d Mon Sep 17 00:00:00 2001
From: OJ Kwon <kwon.ohjoong@gmail.com>
Date: Fri, 9 Jun 2017 02:09:58 -0700
Subject: [PATCH] Completes nodeCrawl with empty roots (#3776)

---
 .../src/crawlers/__tests__/node-test.js         | 17 +++++++++++++++++
 packages/jest-haste-map/src/crawlers/node.js    |  6 +++++-
 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 e488f9d70215..edf90acbb10a 100644
--- a/packages/jest-haste-map/src/crawlers/__tests__/node-test.js
+++ b/packages/jest-haste-map/src/crawlers/__tests__/node-test.js
@@ -198,4 +198,21 @@ describe('node crawler', () => {
       });
     });
   });
+
+  it('completes with emtpy roots', () => {
+    process.platform = 'win32';
+
+    nodeCrawl = require('../node');
+
+    const files = Object.create(null);
+    return nodeCrawl({
+      data: {files},
+      extensions: ['js'],
+      forceNodeFilesystemAPI: true,
+      ignore: pearMatcher,
+      roots: [],
+    }).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 3b35c6cd40b8..a121ba236080 100644
--- a/packages/jest-haste-map/src/crawlers/node.js
+++ b/packages/jest-haste-map/src/crawlers/node.js
@@ -65,7 +65,11 @@ function find(
     });
   }
 
-  roots.forEach(search);
+  if (roots.length > 0) {
+    roots.forEach(search);
+  } else {
+    callback(result);
+  }
 }
 
 function findNative(