[Bug]: mock factory hoisting fails with 'mock' prepended variables

[john-u]

Version

27.1.1

Steps to reproduce

1. Clone my repo at https://github.com/john-u/jest-mock-hoist-issue
2. npm install
3. npm test
4. Both provided tests should fail with something similar to ReferenceError: Cannot access 'mockExampleClient' before initialization

Expected behavior

As stated in jests docs, I expect variables prepended with mock to be defined outside of the mock factory without issue.

A limitation with the factory parameter is that, since calls to jest.mock() are hoisted to the top of the file, it's not possible to first define a variable and then use it in the factory. An exception is made for variables that start with the word 'mock'.

Actual behavior

An error is thrown: ReferenceError: Cannot access 'mock' before initialization where mock is a variable defined outside of the moduleFactory parameter passed to jest.mock().

Additional context

continues #10996

Environment

System:
    OS: macOS 11.4
    CPU: (12) x64 Intel(R) Core(TM) i7-8850H CPU @ 2.60GHz
  Binaries:
    Node: 14.17.6 - ~/.nvm/versions/node/v14.17.6/bin/node
    npm: 6.14.15 - ~/.nvm/versions/node/v14.17.6/bin/npm
  npmPackages:
    jest: ^27.1.1 => 27.1.1

[SimenB]

I think we need to improve the docs - the exception is that Jest doesn't throw when parsing the file, it's not an exception to the limitation. That limitation comes from how JS works and nothing we can do about it. The error message from the code is clearer than the docs: #11455 (comment)

[github-actions]

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