fix(utils): fetch bindings

[alexandre-abrioux]

Motivation and Resolution

When running tests with Jest using testEnvironment: "jsdom" to simulate a browser environment, globalThis is defined but globalThis.fetch is removed by Jest.

When using Starknet's Javascript library, we end up with the following error in tests:

TypeError: Cannot read properties of undefined (reading 'bind')

This is a fix to remediate that issue.

Usage related changes

N/A

Development related changes

N/A

Checklist:

• Performed a self-review of the code
• Rebased to the last commit of the target branch (or merged it into my branch)
• Linked the issues which this PR resolves
• Documented the changes in code (API docs will be generated automatically)
• Updated the tests
• All tests are passing

[tabaktoni]

This would produce an issue if globalThis, window, global are unreferenced.

typeof a?.fetch

VM6129:1 Uncaught ReferenceError: a is not defined
    at <anonymous>:1:1

On the other hand, for unreferenced elements, this is fine

typeof a

'undefined'

fetch is a known issue with jsdom, and is not the best solution for testing. There are multiple issues and references to using a headless browser rather than it.
But in this case, you can also set this at the start of the code execution:
config.set('fetch', yourfetch);

[alexandre-abrioux]

@tabaktoni Thanks for reviewing this PR! And I apologize for my mistake; I should have tested this further.

I agree that jsdom is not the best solution, and ideally, we should use a headless browser. Unfortunately, I'm currently unable to do that on the project I'm working on, but I've already applied a quick fix, similar to the one you suggested.

The goal of this PR was to contribute a general fix that would prevent it from happening to someone else. I updated the condition, and it should now work for all cases. Let me know what you think!