hi team, I have this PR to support Union type in flyteidl. https://github.com/flyteorg/flyteidl/pull/401 However, i do have a few questions related to what I should generate when making the default value for Union types. Currently I am generating it as a Union Scalar with the first type available. However, I can also just generate the the literal for the type itself. Wondering if that make a difference when user creating the task using simple types but task is defined as Union type. An example:

@task
def task(a: Union[Integer, Float]):

and then I am current generating default value as Union scalar literal:

x:
        value:
            value:
                scalar:
                    value:
                        primitive:
                            value:
                                integer: 0
                            xxx_nounkeyedliteral: {}
                            xxx_unrecognized: []
                            xxx_sizecache: 0
                    xxx_nounkeyedliteral: {}
                    xxx_unrecognized: []
                    xxx_sizecache: 0
            hash: ""
            xxx_nounkeyedliteral: {}
            xxx_unrecognized: []
            xxx_sizecache: 0
        type:
            type:
                simple: 1
            metadata: null
            annotation: null
            structure:
                tag: int
                xxx_nounkeyedliteral: {}
                xxx_unrecognized: []
                xxx_sizecache: 0
            xxx_nounkeyedliteral: {}
            xxx_unrecognized: []
            xxx_sizecache: 0
        xxx_nounkeyedliteral: {}
        xxx_unrecognized: []
        xxx_sizecache: 0

or I can generate default as simple integer literal like this:

"x": 0

@hallowed-mouse-14616 @freezing-airport-6809 @glamorous-carpet-83516

Currently I am generating it as a Union Scalar with the first type available

yes, I think it’s fine because

MakeDefaultLiteralForType

is only used in the tests.

```@task

def task(a: Union[Integer, Float]):```

flytekit always expects

a

is a Union scalar literal

cool, thanks, but why does the scalar contains so many other fields like

xxx_unrecognized: []

same q ^^

oh, sorry. I though it’s only used in idl. looking the code in flytectl. that’s auto generated by protobuf

so when I extract from a Union Literal, should I just get the actual value inside the union or the union type defined here https://github.com/flyteorg/flyteidl/blob/44b6bc64337cb40b08865ab6c1c8762f4d9619e4/protos/flyteidl/core/literals.proto#L56