Link to the code that reproduces this issue

https://github.com/arthur-zhao-anrok/next_bug_repro_repo

To Reproduce

1. cd reproduction-app/
2. npm install
3. npm run test

Current vs. Expected behavior

Current behavior: the test errs out with the following error:

/Users/xxxx/Github/next_bug_repro_repo/reproduction-app/app/font_util.js:4
var aktivGrotesk = (0, local_1.default)({
                                       ^

TypeError: (0 , local_1.default) is not a function
    at Object.<anonymous> (/Users/arthurzhao/Github/next_bug_repro_repo/reproduction-app/app/font_util.js:4:40)
    at Module._compile (node:internal/modules/cjs/loader:1119:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1173:10)
    at Module.load (node:internal/modules/cjs/loader:997:32)
    at Module._load (node:internal/modules/cjs/loader:838:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)
    at node:internal/main/run_main_module:18:47

Node.js v18.8.0

Expected behavior: the test should run successfully.

Verify canary release

• I verified that the issue exists in the latest Next.js canary release

Provide environment information

Operating System:
   Platform: darwin
   Arch: arm64
   Version: Darwin Kernel Version 21.3.0: Wed Jan  5 21:37:58 PST 2022; root:xnu-8019.80.24~20/RELEASE_ARM64_T6000

Binaries:
   Node: 18.8.0
   npm: 8.18.0
   Yarn: 4.0.0-rc.38
   pnpm: N/A

Relevant Packages:
   next: 13.5.1-canary.1
   eslint-config-next: N/A
   react: 18.2.0
   react-dom: 18.2.0
   typescript: 5.1.3
    
Next.js Config:
   output: N/A

Which area(s) are affected? (Select all that apply)

Font optimization (next/font)

Additional context

I tested my reproduction against both the canary release and v13.4.10.

In my actual production project, I used localFont() in a module called theme.ts that is used by multiple frontend components. It works well in production when those frontend components were used as part of the Next.js frontend app.

However, when I used Jest to test the modules that relies on theme.ts, the tests would err out when importing those modules. I ended up mocking next/font/local to circumvent the issue.

Similar issue on StackOverflow: https://stackoverflow.com/questions/76659367/typeerror-0-local-default-is-not-a-function-when-using-next-font-local-in-j