Testing optional keys only

[mahadi]

As a part of my application i am testing the schema validation. For a specific section of my configuration i have a Map which contains an optional username and password (and other keys).

I want to test that both combinations wont raise an error during the validation.
To be able to test only the relevant parts of my schema i only extracted the username and password schema part and provided an empty string, simulating that none of the keys has been provided.

I only want to test the optional keys because i already have tests for the other keys, so i dont want to include any of them again.

Shouldnt the following test pass?

from strictyaml import Map, Str, Optional, load
from ensure import Ensure
schema = Map({Optional("username"): Str(), Optional("password"): Str()})
Ensure(load('', schema)).equals({})

It raises:

strictyaml.exceptions.YAMLValidationError: when expecting a mapping
found a blank string
  in "<unicode string>", line 1, column 1:
    ''
     ^ (line: 1)

[crdoconnor]

No, it shouldn't. The Map validator implies that there should be at least one key and value, even though both individually are optional. If you wanted it to be possible to have neither, you would need

EmptyDict() | Map({Optional("username"): Str(), Optional("password"): Str()}).

[mahadi]

Thank you for the explanation, it works as you proposed.