Add warning message if domain yml file is not valid

[raoulvm]

yaml syntax

Issue a logging warning if a domain file is invalid YAML syntax.

We at Deutsche Telekom encountered the issue that somebody put an invalid yaml file in our domain folder. The errors we got were just about missing intents in the domain. We expected to get some warning about the file being ignored due to invalid yaml though.

Status (please check what you already did):

• added some tests for the functionality
• updated the documentation
• updated the changelog (please check changelog for instructions)
• reformat files using black (please check Readme for instructions)

[CLAassistant]

All committers have signed the CLA.

[sara-tagger]

Thanks for submitting a pull request 🚀 @samsucik will take a look at it as soon as possible ✨

[ancalita]

Thank you for your contribution 🚀
Could you please share more details on how to replicate the issue - what was the invalid yaml syntax and what command did you run?

Please address the following items:

• swap to utility function raise_warning as in the comment
• add a test in tests/shared/core/test_domain.py to replicate the issue and check that the correct warning is raised
• add a changelog entry (the type should be improvement)

Let me know if you have any q's for me 👍

[raoulvm]

pytest added to tests/shared/core/test_domain.py

If there is anything missing, please ping me, @ancalita and @erohmensing

[raoulvm]

ok, I am lost.
The pipeline says

poetry run black --check rasa tests
would reformat /home/runner/work/rasa/rasa/rasa/shared/core/domain.py
would reformat /home/runner/work/rasa/rasa/tests/shared/core/test_domain.py
Oh no! 💥 💔 💥
2 files would be reformatted, 463 files would be left unchanged.

my black says

(rasa) A1146056@T000a53137 rasa % black --check rasa/shared/core/domain.py 
All done! ✨ 🍰 ✨
1 file would be left unchanged.
(rasa) A1146056@T000a53137 rasa % black --check tests/shared/core/test_domain.py 
All done! ✨ 🍰 ✨
1 file would be left unchanged.

however, it suggests to change 79 other files on my pc.
Any specific black settings I should know of?

[raoulvm]

@ancalita maybe the black version is different? I installed "latest" which was at that time

black, version 21.6b0

What is your pipeline using?

[ancalita]

💯