[BUG] TypeError: can't convert null to object if using wrong default in dataclass

[fellhorn]

Describe the bug

When trying to launch a workflow with a faulty dataclass the UI breaks with an unhelpful react error as shown in the screenshot:

The error we received was:
TypeError: can't convert null to object

There may be additional information in the browser console.

Please find this minimal example workflow:

from typing import Optional, Dict

from dataclasses import dataclass
from dataclasses_json import dataclass_json
from flytekit import task, workflow


@dataclass_json
@dataclass
class MyConfig:
    k: Optional[Dict] = None


@task
def t1(a: MyConfig) -> str:
    if a.k and "foo" in a.k:
        return a.k["foo"]
    else:
        return "42"


@workflow
def my_wf(a: MyConfig = MyConfig()) -> str:
    x = t1(a=a)
    return x

where k has a wrong default. Instead of k: Optional[Dict] = None, it should be

from dataclasses import field

@dataclass_json
@dataclass
class MyConfig:
    k: Optional[Dict] = field(default_factory=lambda: {})

Expected behavior

I am aware of the error on the user side.
Still: I think flyte could show a more helpful error message here to point to the bad parameter.

Additional context to reproduce

The error shown in the browser dev console is:

TypeError: can't convert null to object
**REDACTED**
 
Object { componentStack: "\n    in Unknown\n    in div\n    in S\n    in section\n    in ForwardRef\n    in div\n    in ForwardRef\n    in ForwardRef\n    in Unknown\n    in Unknown\n    in div\n    in ForwardRef\n    in ForwardRef\n    in div\n    in t\n    in ForwardRef\n    in s\n    in div\n    in ForwardRef\n    in ForwardRef\n    in ForwardRef\n    in ForwardRef\n    in Unknown\n    in E\n    in Unknown\n    in Unknown\n    in Unknown\n    in E\n    in div\n    in Unknown\n    in Unknown\n    in t\n    in t\n    in Unknown\n    in E\n    in t\n    in div\n    in t\n    in Unknown\n    in l\n    in c\n    in l\n    in Unknown\n    in Unknown\n    in Unknown" }
main-965d5331.js:1:369655

Screenshots

Are you sure this issue hasn't been raised already?

• Yes

Have you read the Code of Conduct?

• Yes

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