[babel-plugin-jest-hoist] Fix MockNativeMethods access in react-native

CHANGELOG.md

@@ -5,6 +5,7 @@
 - `[jest-config]` Add missing options to the `defaults` object ([#6428](https://github.com/facebook/jest/pull/6428))
 - `[expect]` Using symbolic property names in arrays no longer causes the `toEqual` matcher to fail ([#6391](https://github.com/facebook/jest/pull/6391))
 - `[expect]` `toEqual` no longer tries to compare non-enumerable symbolic properties, to be consistent with non-symbolic properties. ([#6398](https://github.com/facebook/jest/pull/6398))
+- `[jest-mock]` Fix `MockNativeMethods` access in react-native `jest.mock()` ([#6505](https://github.com/facebook/jest/pull/6505))
 
 ### Chore & Maintenance
 

e2e/babel-plugin-jest-hoist/__test_modules__/f.js

@@ -0,0 +1,8 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+export default () => 'unmocked';

e2e/babel-plugin-jest-hoist/__tests__/integration.test.js

@@ -61,6 +61,10 @@ jest.dontMock('../__test_modules__/Mocked');
 const myObject = {mock: () => {}};
 myObject.mock('apple', 27);
 
+// Variable names prefixed with `mock` (ignore case) should not throw as out-of-scope
+const MockMethods = () => {};
+jest.mock('../__test_modules__/f', () => MockMethods);
+
 describe('babel-plugin-jest-hoist', () => {
   it('does not throw during transform', () => {
     const object = {};

packages/babel-plugin-jest-hoist/src/index.js

@@ -110,7 +110,7 @@ FUNCTIONS.mock = args => {
       if (!found) {
         invariant(
           (scope.hasGlobal(name) && WHITELISTED_IDENTIFIERS[name]) ||
-            /^mock/.test(name) ||
+            /^mock/i.test(name) ||
             // Allow istanbul's coverage variable to pass.
             /^(?:__)?cov/.test(name),
           'The module factory of `jest.mock()` is not allowed to ' +
@@ -123,7 +123,7 @@ FUNCTIONS.mock = args => {
             '.\n' +
             'Note: This is a precaution to guard against uninitialized mock ' +
             'variables. If it is ensured that the mock is required lazily, ' +
-            'variable names prefixed with `mock` are permitted.',
+            'variable names prefixed with `mock` (case insensitive) are permitted.',
         );
       }
     }