fix(sdk): fix support for args when using IndexifyFunction and IndexifyRouter classes

[seriousben]

Context

We introduced a regression making this graph fail:

        class MyObject(BaseModel):
            x: int

        class SimpleFunctionCtxCls(IndexifyFunction):
            name = "SimpleFunctionCtxCls"

            def __init__(self):
                super().__init__()

            def run(self, obj: MyObject) -> MyObject:
                return MyObject(x=obj.x + 1)

        graph = Graph(name="test_simple_function_cls", start_node=SimpleFunctionCtxCls)
        graph = remote_or_local_graph(graph, is_remote)
        invocation_id = graph.run(block_until_done=True, obj=MyObject(x=1))
        output = graph.output(invocation_id, "SimpleFunctionCtxCls")
        self.assertEqual(output, [MyObject(x=2)])

It failed because it called the run function with dict(obj=MyObject(x=1)) instead of just MyObject(x=1).

What

Recent improvements to args and kwargs handling missed support for IndexifyFunction and IndexifyRouter classes.

This PR aligns the approach taken for function and classes.

Testing

Add a new test case for IndexifyFunction and IndexifyRouter classes.

Contribution Checklist

• If the python-sdk was changed, please run make fmt in python-sdk/.
• If the server was changed, please run make fmt in server/.
• Make sure all PR Checks are passing.

[stangirala]

+1 (needs pr check fix)

[eabatalov]

Can we only use the isinstance check here?
It's clear easier to maintain if it gives the same results.

[seriousben]

From my testing, the way we build the IndexifyFunction using type(...) fails the is instance check.

Will do more testing.

[eabatalov]

Interesting. If isinstance() fails and we won't figure out why, then let's not add isinstance() here and add a comment that's it's not working. So others don't try to quickfix it with the isinstance() check.

[seriousben]

I would not be adding code for no reason :)

The isintance is needed when using the IndexifyRouter class. But it looks like when using the indexify_router function, it is not enough.

[eabatalov]

TIL :)

[seriousben]

Looks like it can either be an instance or a class.