[BUG] Variable API throws BadRequest when type mismatch

[jeanbaptistedalle]

Description

Set variable to a value that doesn't match his definition will success but the instance will not be displayed correctly.

Steps to Reproduce

1. Create a workflow with some variables, like a variable called "Var1" of type Int32.
2. In a javascript activity, set this variable with some value that doesn't match the type. For our business case, that could happend when the data I got from elsewhere are not as I expected.
3. Run the workflow. It will run successfully.
4. Try to display the instance, the variable API will throw a badrequest exception and the instance will not be successfully display.

Screenshots

Record.2024-12-09.141950.mp4

Expected Behavior

I'm not sure what is the good way to fix it. The variable API result seems to be correct : the type mismatch with the value. But the instance is successfull and then cannot be display. Maybe that's more when the variable is set that a failure should happend to let user see the type mismatch in the variable instance ?

[sfmskywalker]

Short term, at the very least, we should make sure the designer / workflow instance viewer doesn't break. Mid-term, perhaps the activity should fault.

[sfmskywalker]

PS. Nice catch 👍🏻

[sfmskywalker]

Fixed via #6207