Fixed crash when --domain not provided for rasa train command

[RanaMostafaAbdElMohsen]

Fixes #3794

Proposed changes:

• An Error message will be displayed in case of invalid domain file provided
  or no domain file provided at all for rasa train core only
• One more additional check added to --domain argument

Tests:

• [CORE] Provide Invalid domain file path [Error Message Displayed]
  python rasa/rasa train core --domain rasa/examples/formbot/domain1.yml --config rasa/examples/formbot/config.yml --stories rasa/examples/formbot/data/ --out rasa/examples/formbot/models --augmentation 0 --quiet

• [CORE] No domain file provided [Error Message Displayed]
  python rasa/rasa train core --config rasa/examples/formbot/config.yml --stories rasa/examples/formbot/data/ --out rasa/examples/formbot/models --augmentation 0 --quiet

• [CORE] Provided valid domain file [PASS]
  python rasa/rasa train core --domain rasa/examples/formbot/domain.yml --config rasa/examples/formbot/config.yml --stories rasa/examples/formbot/data/ --out rasa/examples/formbot/models --augmentation 0 --quiet

• [NLU] No domain file provided [PASS]
  python rasa/rasa train nlu --config rasa/examples/formbot/config.yml --nlu rasa/examples/formbot/data/ --out rasa/examples/formbot/models

Status (please check what you already did):

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

[CLAassistant]

All committers have signed the CLA.

[akelad]

Thanks for submitting this PR, we'll give it a review as soon as possible!

[erohmensing]

Hi @RanaMostafaAbdElMohsen! A few things before I make a thorough review:

1. Now that there have been some updates to the command (I believe due to a PR for making sure temp directories get deleted), would you please solve the merge conflicts?
2. Your first test makes sense -- if the provided domain is invalid, it should raise an error, not break. However, if you do rasa train core without providing a domain (2nd test case), in my opinion, the ideal behavior is that it would look for domain.yml, like rasa train and rasa train nlu does. Can you make that happen?

BTW, thanks for making your first PR well-tested and super descriptive! Looking forward to adding you as a code contributor. 😄

[RanaMostafaAbdElMohsen]

Hi @erohmensing ,
Thanks for your feedback. I would like to bring your attention to two of test cases in
testing directory :

tests/cli/test_rasa_train.py

test case 1 :

test_train_core_temp_files

test case 2 :

test_train_nlu_temp_files

These two test cases failed locally on my machine; however, the test cases pass on travis CI.
The test case fails due to function count_rasa_temp_files()

It fails due to permission error
for f in os.listdir(entry.path): PermissionError: [Errno 13] Permission denied: '/tmp/systemd-private'
I believe a bug should be fired to handle this missing scenario in case of permission denied files

[RanaMostafaAbdElMohsen]

@erohmensing ,
Referring to point number 2 that you have mentioned it in your previous comment for 2nd testcase.
In fact, it already searches for domain.yml but in its command working directory but not in passed directory as --config argument and --stories argument. It already mimics same behaviour as rasa train core and rasa train.

Here are some test scenarios in case we made it look for domain.yml in same directory passed for --config and --stories argument which user may find rather misleading :

• Problem here that user may pass different directories in command for --config and--stories as test scenario. So in that case, the domain file will be searched in which directory?!

• Another test scenario, what if directory passed for --config and --stories are not found, the domain will be searched in this unfound directory

• Another test scenario which I find it very convincing, what if user wants to run domain.yml file that is found to be existing in command working directory but not the other domain file referenced at directory passed for --config and --stories argument.

I believe that the best course of action is that if not referenced directory for domain.yml, it will search for it in current working directory same as rasa train core and rasa train commands which is already covered.

[erohmensing]

I believe that the best course of action is that if not referenced directory for domain.yml, it will search for it in current working directory same as rasa train core and rasa train commands which is already covered.

I totally agree, and I understand what you mean now. I was thinking in the case of the working dir being the one with domain.yml in it, but obviously that's not the case. Thanks for the clarification!

[erohmensing]

Functionality looks good! Just a few comments on the error/warning messages.

[erohmensing]

@federicotdn can you look into what he mentioned above about the temp dir tests? #3914 (comment)

[federicotdn]

@erohmensing fixed! Take a look: #3958
@RanaMostafaAbdElMohsen you would need to update your branch after that PR is merged. Sorry for the inconvenience.

[RanaMostafaAbdElMohsen]

hello @erohmensing ,
I have resolved all comments that you have advised.
Please review it.

[erohmensing]

Awesome, thanks for the fix! Congrats on being a code contributor!

Edit: Oops, I'm sorry I forgot one last thing. Can you please update the changelog? It should go under fixed -- something like
``rasa train core`` no longer crashes without a ``--domain`` arg

(the double ticks are .rst notation for this style) I'd fix it myself but I can't write to your repo. Almost got too merge-happy 😅

[RanaMostafaAbdElMohsen]

Awesome, thanks for the fix! Congrats on being a code contributor!

Edit: Oops, I'm sorry I forgot one last thing. Can you please update the changelog? It should go under fixed -- something like
rasa train core no longer crashes without a --domain arg

(the double ticks are .rst notation for this style) I'd fix it myself but I can't write to your repo. Almost got too merge-happy 😅

Thanks @erohmensing for your help.
Done.

[erohmensing]

Sorry, it should go under unreleased master version, not 1.1.4. Sorry for the confusion, thanks for responding so fast! (in the future, allowing people with write access to edit your contribution makes small things like this a lot easier!)

[RanaMostafaAbdElMohsen]

Sorry, it should go under unreleased master version, not 1.1.4. Sorry for the confusion, thanks for responding so fast! (in the future, allowing people with write access to edit your contribution makes small things like this a lot easier!)

Sorry for wrong placement. Done :D
When is it expected to be merged @erohmensing ?