diff --git a/jest/__tests__/hasteImpl-test.js b/jest/__tests__/hasteImpl-test.js
new file mode 100644
index 00000000000000..de493aa9a153da
--- /dev/null
+++ b/jest/__tests__/hasteImpl-test.js
@@ -0,0 +1,93 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ * @emails oncall+js_foundation
+ */
+
+'use strict';
+
+const path = require('path');
+
+const {getHasteName} = require('../hasteImpl');
+
+function getPath(...parts) {
+  return path.join(__dirname, '..', '..', ...parts);
+}
+
+it('returns the correct haste name for a RN library file', () => {
+  expect(
+    getHasteName(
+      getPath(
+        'Libraries',
+        'Components',
+        'AccessibilityInfo',
+        'AccessibilityInfo.js',
+      ),
+    ),
+  ).toEqual('AccessibilityInfo');
+});
+
+it('returns the correct haste name for a file with a platform suffix', () => {
+  for (const platform of ['android', 'ios', 'native', 'web', 'windows']) {
+    expect(
+      getHasteName(
+        getPath(
+          'Libraries',
+          'Components',
+          'AccessibilityInfo',
+          `AccessibilityInfo.${platform}.js`,
+        ),
+      ),
+    ).toEqual('AccessibilityInfo');
+  }
+});
+
+it('returns the correct haste name for a file with a flow suffix', () => {
+  expect(
+    getHasteName(
+      getPath(
+        'Libraries',
+        'Components',
+        'AccessibilityInfo',
+        'AccessibilityInfo.ios.js.flow',
+      ),
+    ),
+  ).toEqual('AccessibilityInfo');
+});
+
+it('does not calculate the haste name for a file that is not JS', () => {
+  expect(
+    getHasteName(
+      getPath(
+        'Libraries',
+        'Components',
+        'AccessibilityInfo',
+        'AccessibilityInfo.txt',
+      ),
+    ),
+  ).toBe(undefined);
+});
+
+it('does not calculate the haste name for a file outside of RN', () => {
+  expect(
+    getHasteName(getPath('..', 'Libraries', 'AccessibilityInfo.txt')),
+  ).toBe(undefined);
+});
+
+it('does not calculate the haste name for a blacklisted file', () => {
+  expect(
+    getHasteName(
+      getPath(
+        'Libraries',
+        'Components',
+        '__mocks__',
+        'AccessibilityInfo',
+        'AccessibilityInfo.js',
+      ),
+    ),
+  ).toBe(undefined);
+});
diff --git a/jest/hasteImpl.js b/jest/hasteImpl.js
index e72fa4f37b26ab..8f02881c51bfa5 100644
--- a/jest/hasteImpl.js
+++ b/jest/hasteImpl.js
@@ -18,9 +18,9 @@ const ROOTS = [
 ];
 
 const BLACKLISTED_PATTERNS /*: Array<RegExp> */ = [
-  /.*\/__(mocks|tests)__\/.*/,
-  /^Libraries\/Animated\/src\/polyfills\/.*/,
-  /^Libraries\/Renderer\/fb\/.*/,
+  /.*[\\\/]__(mocks|tests)__[\\\/].*/,
+  /^Libraries[\\\/]Animated[\\\/]src[\\\/]polyfills[\\\/].*/,
+  /^Libraries[\\\/]Renderer[\\\/]fb[\\\/].*/,
 ];
 
 const WHITELISTED_PREFIXES /*: Array<string> */ = [
@@ -32,7 +32,7 @@ const WHITELISTED_PREFIXES /*: Array<string> */ = [
 
 const NAME_REDUCERS /*: Array<[RegExp, string]> */ = [
   // extract basename
-  [/^(?:.*\/)?([a-zA-Z0-9$_.-]+)$/, '$1'],
+  [/^(?:.*[\\\/])?([a-zA-Z0-9$_.-]+)$/, '$1'],
   // strip .js/.js.flow suffix
   [/^(.*)\.js(\.flow)?$/, '$1'],
   // strip .android/.ios/.native/.web suffix