Make errors more friendly (INTERNALERROR>) #2293
Description
In general, users end up seeing a lot of INTERNALERROR> messages which are not really internal errors, but are uncaught exceptions which are not treated correctly.
For example, if a user mistypes a hook name in a conftest.py file (for example, pytest_confiure), here's what is displayed:
INTERNALERROR> Traceback (most recent call last):
INTERNALERROR> File "C:\pytest\_pytest\main.py", line 98, in wrap_session
INTERNALERROR> session.exitstatus = doit(config, session) or 0
INTERNALERROR> File "C:\pytest\_pytest\main.py", line 132, in _main
INTERNALERROR> config.hook.pytest_collection(session=session)
INTERNALERROR> File "C:\pytest\_pytest\vendored_packages\pluggy.py", line 745, in __call__
INTERNALERROR> return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
INTERNALERROR> File "C:\pytest\_pytest\vendored_packages\pluggy.py", line 339, in _hookexec
INTERNALERROR> return self._inner_hookexec(hook, methods, kwargs)
INTERNALERROR> File "C:\pytest\_pytest\vendored_packages\pluggy.py", line 302, in __call__
INTERNALERROR> return outcome.get_result()
INTERNALERROR> File "C:\pytest\_pytest\vendored_packages\pluggy.py", line 279, in get_result
INTERNALERROR> raise ex[1].with_traceback(ex[2])
INTERNALERROR> File "C:\pytest\_pytest\vendored_packages\pluggy.py", line 265, in __init__
INTERNALERROR> self.result = func()
INTERNALERROR> File "C:\pytest\_pytest\vendored_packages\pluggy.py", line 300, in <lambda>
INTERNALERROR> outcome = _CallOutcome(lambda: self.oldcall(hook, hook_impls, kwargs))
INTERNALERROR> File "C:\pytest\_pytest\vendored_packages\pluggy.py", line 334, in <lambda>
INTERNALERROR> _MultiCall(methods, kwargs, hook.spec_opts).execute()
INTERNALERROR> File "C:\pytest\_pytest\vendored_packages\pluggy.py", line 614, in execute
INTERNALERROR> res = hook_impl.function(*args)
INTERNALERROR> File "C:\pytest\_pytest\main.py", line 141, in pytest_collection
INTERNALERROR> return session.perform_collect()
INTERNALERROR> File "C:\pytest\_pytest\main.py", line 597, in perform_collect
INTERNALERROR> self.config.pluginmanager.check_pending()
INTERNALERROR> File "C:\pytest\_pytest\vendored_packages\pluggy.py", line 498, in check_pending
INTERNALERROR> (name, hookimpl.plugin))
INTERNALERROR> _pytest.vendored_packages.pluggy.PluginValidationError: unknown hook 'pytest_confiure' in plugin <module 'conftest' (<_pytest.assertion.rewrite.AssertionRewritingHook object at 0x03911090>)>
======================== no tests ran in 0.01 seconds =========================
Fixture, collection, etc all have their own exception classes that are treated specially and displayed nicely (which is good), but I feel we should have more general classes that can be raised from anywhere in the code and would signal pytest that something is wrong and display a nice message. Perhaps UsageError is supposed to be it and just needs some polish?
Would like to brainstorm some ideas. I would like to improve things for 3.1 if possible.