[typing] prefect.client

[mjpieters]

Code now passes pyright checking in strict mode.

[codspeed-hq]

CodSpeed Performance Report

Merging #16265 will not alter performance

_{Comparing mjpieters:prefect_client_annotations (67d1b4f) with main (1c30778)}

Summary

✅ 3 untouched benchmarks

[desertaxle]

Thanks @mjpieters!

[zzstoatzz]

commenting for visibility

[mjpieters]

I may have used the wrong special form here. This type narrowing function returns a TypeIs construct but now that I reread this it should have been a TypeGuard instead.

That's because this function returns False in two different cases:

1. the client is a SynPrefectClient instance.
2. the client is a PrefectClient instance, attached to a different loop.

The TypeIs construct acts like an isinstance() check, where the type checker can infer that if False is returned then the client must be a SyncPrefectClient as that's the only type left out of the input Union. But that's not correct for case 2.

A TypeGuard function explicitly doesn't make promises about types when False is returned and so fits this function much better.

It is a technically moot point in how this function is used in this module but an important distinction if you were to use this as an example 🤦.

TLDR:

• use TypeIs[R] when True means this is of type R and False means this is not of type R
• use TypeGuard[R] when True means this meets conditions that tell me this is of type R but False means uh, I am not sure what this is and I don't care 🤷.

[zzstoatzz]

thank you @mjpieters !