flag_value paramters are cast with the wrong type

[antoniivanov]

Since click 8.0 passing flag_value enum value , it is converting it to string which breaks the CLI. (7.x works fine)

For example

@unique
class Operation(Enum): 
    CREATE = "create"
    UPDATE = "update" 

@click.option(
    "--update",
    "operation",
    flag_value=Operation.UPDATE
)
@click.option(
    "--create",
    "operation",
    flag_value=Operation.CREATE
)
def my_cli(operation)
   if operation == Operation.CREATE: 
       print("create")
  
 if operation == Operation.UPDATE: 
       print("UPDATE")

if are run it with cli --create

Expected behavior

operation is Operation.CREATE of type Operation and the cli prints "create"

Actual behavior
operation is a string with value "Operation.CREATE" and the cli prints nothing

Environment:

• Python version: 3.7+
• Click version: 8.0

[davidism]

The default param type for types that Click does not have special handling for is str. Click does not have special handling for Enum. The processing pipeline was updated to apply type casting to all data sources consistently. Either use type=click.UNPROCESSED or write a custom type to handle enum members.