Fetch-Mock transpilation doesn't work for IE 11 for ^v3.1.0

[canrozanes]

• I HAVE READ THE FAQ AND MY PROBLEM WAS NOT DESCRIBED THERE

Are you trying to transpile a local package or an npm package?
Fetch-Mock for IE 11

Describe the bug
I recently upgraded next-transpile-modules from v2.3.1 to 3.1.0.
As soon as I upgraded my project started to fail in IE-11 due to fetch-mock.

I know the docs specifically mention that this plugin does not aim to make any package IE-11 compatible but either way, I found it odd the package had no problem transpiling in previous versions.

To Reproduce
I built a small scale repro here
If you run the project in IE-11 it fails, if you down version next-transpile-modules@2.3.1 and build again, it works on IE-11.

Expected behavior
Expectation is, the latest version of next-transpile-modules supports transpiling IE 11 just like the earlier versions.

Setup

• Next.js version: 9.3.1
• next-transpile-modules version: 3.1.0
• Node.js version: 12.13.1
• npm version: 6.12.1
• Operating System: MacOS 10.14.6

Additional context
Related Fetch-Mock issue is here:
wheresrhys/fetch-mock#415

The question to me is, why did the earlier version of next-transpile-modules patched the above problem but the new version no longer does.

[martpie]

I will try to see what is wrong with the repro :)

Out of curiosity, why do you need fetch-mock in the browser? Isn't this something only used by Node when running tests?

[canrozanes]

We use fetch-mock on the browser if we are building a feature that requires both front end and back end work and the back end work for the feature isn't ready yet. In that case, front end developers mock the API responses using fetch-mock and develop the feature as if they are working with a fully functional API.

[martpie]

Closing for inactivity, and new version of Next and next-transpile-modules are available and might fix this. I'll re-open if there is still a problem.