pylxd/client: inspect secret before trying to use it as a token

[simondeziel]

No description provided.

[hamistao]

Our unit tests are pretty terrible. So to spare you from working with that while we don't improve them, I would be fine with just testing:

• authenticate with an actual token;
• authenticate with a password and check it fallsback to using a password if a token is not provided;
• use_token_field as False and forcing password usage;

Then again if you think a unit test is needed here go for it :)

[hamistao]

Also may be worth adding something on https://github.com/canonical/pylxd/blob/main/doc/source/authentication.rst

[simondeziel]

Our unit tests are pretty terrible.

Can't agree more!

So to spare you from working with that while we don't improve them, I would be fine with just testing:

* authenticate with an actual token;

* authenticate with a password and check it fallsback to using a password if a token is not provided;

* `use_token_field` as False and forcing password usage;

Then again if you think a unit test is needed here go for it :)

Yeah, I went the doctest route thinking it would be simple but turns out not as much as I'd like. Let me know what you think of the current proposal, please.

[hamistao]

Sharp idea with the doctests. We could consider rewriting our unit tests as doctests at some point (far in the future perhaps).