If it’s really just two params that shall be the same (like password and it’s repetition), one might consider a plain pattern match and a guard that assures that two fields are the same and not nil.
def some_action(conn, %{"field_1" => value, "field_2" => value})
when not is_nil(value) do
# do something with value
end
def some_action(conn, _params) do
# render "field_1 must be equal to field_""
end
For JSON payloads I’d use a JSON schema to validate against.
