Making _CallOutcome.result private in 3.0

[The-Compiler]

I propose to rename pluggy._CallOutcome.result to _result with pytest 3.0. It seems to be a common mistake to use .result instead of get_result():

• Logging hookwrapper hides exceptions pytest-qt#98
• Use outcome.get_result() in hookwrapper rvprasad/pytest-finer-verdicts#1

If there was an exception in the wrapped hook, the result attribute will not exist at all, which will cause an AttributeError which hides the exception which actually happened.

To avoid that mistake, I think it'd be better to only use the attribute internally and only provide get_result as external API.

[RonnyPfannschmidt]

please report against pluggy

i think we could get by by creating a non-data descriptor that raises the actual exception from the actual traceback when used

(non-data descriptors get only triggered if the instance does not have an attribute of the same name)

[The-Compiler]

I reported it here because it'll be a backwards compatibility break in pytest and mainly affect pytest code and users 😉

I guess that'd work as well, but it strikes me as quite weird that an attribute access would raise a (non-AttributeError) exception.

[RonnyPfannschmidt]

i think a nice way to solve this is to make get_result use _result and to have result as a alias property for get_result

[nicoddemus]

I like @RonnyPfannschmidt's idea. 😁

I also have been bitten by this issue myself.

[nicoddemus]

This has been changed already on pluggy, but will become again a read-only property that calls get_result() under the covers in pytest-dev/pluggy#88.