move default retry logic on to defaultOptions

[hahn-kev]

closes #636

it was suggested that the default value of onShouldRetry should be set to shouldRetry but that won't work because shouldRetry calls onShouldRetry, so I opted to move the code at the bottom of shouldRetry into a function declared on defaultOptions. I wasn't quite sure what we wanted to do if a user explicitly set onShouldRetry to null. Currently the default logic would still be used, so that's what I preserved here, though it does look a bit awkward.

I wasn't able to run tests or execute a build locally. I kept getting a build error about a subdirectory or file already existing.

[Acconut]

On a second though, this approach is not ideal because it would be a breaking change for some users. When you are providing a custom onShouldRetry callback, you will no longer receive the check for the status code, like you used to do before.

After thinking more about this, I am unsure if we can use defaultOptions to expose shouldRetry without breaking the behavior for people supplying an onShouldRetry option.

[hahn-kev]

I'm not sure what you mean. If we provide a default value and a user also provides a value the default will be overwritten, then the exact same thing that happens today does. Today if a user provides a function then the default functionality does not run. That hasn't changed.

Also, I didn't expose shouldRetry at all, I just moved some functionality inside of it into the default function. The only thing that's changed from the outside is that if you call defaultOptions.onShouldRetry you will get the default functionality if you didn't provide that option.

[Acconut]

You are right, this PR does not present a breaking change for users.

I have two comments on the code. Could you also please have a look at the lint issues in upload.js: https://github.com/tus/tus-js-client/actions/runs/6573176315/job/17950213388?pr=637#step:7:43

[hahn-kev]

Alright, I've pushed changes and left a comment about the type change.

When I run lint on my machine it gives a bunch of errors and warnings about line endings and files I didn't change, but I think the lint error is fixed.

[Acconut]

Thank you for your help!