Adding Mypy type annotations to domain folder files

This issue will track the type annotation process of all the core/domain/*.py (and their test files). To get started, ask to be assigned to any unclaimed task. Tasks are claimed by adding the username of the claimer to the end of the task, e.g. @example.

Note: Main code file and its test file must be type-annotated together.

The general procedure to add type annotations is as follows:

1. Start with the main code file first.
2. Remove the file to be annotated from the mypy denylist (i.e. from NOT_FULLY_COVERED_FILES in scripts/run_mypy_checks.py). Run the mypy checks on the code file using python -m scripts.run_mypy_checks --files <path/to/file> to understand all the errors mypy is reporting for this file.
3. Go over them one by one, and fix them by following the detailed instructions as mentioned in our wiki.
4. PAY ATTENTION to our guidelines for using type ignores in the codebase.
5. For testing the changes after annotating all the files, run python -m scripts.run_mypy_checks, which runs the type checks on the entire codebase, and ensure that no errors are being reported.
6. If errors occur in other files due to you change make sure to also fix those other files.

Good examples of already annotated files in the codebase:

1. Check out the core/storage folder.
2. Ref PR for domain file type annotation: #14034

If you face problems in understanding a particular case while adding annotations, please go over the tips mentioned in the wiki once, and let us know if you are still stuck!

Tasks/files:

• core/domain/action_registry.py@sahiljoster32
• core/domain/activity_services.py@sahiljoster32
• core/domain/auth_services.py @IamhappyXD
• core/domain/blog_services.py @IamhappyXD
• core/domain/calculation_registry.py@sahiljoster32
• core/domain/classifier_services.py
• core/domain/classroom_services.py @SD-13
• core/domain/collection_services.py
• core/domain/config_services.py@sahiljoster32
• core/domain/cron_services.py @SD-13
• core/domain/customization_args_util.py
• core/domain/draft_upgrade_services.py
• core/domain/email_manager.py
• core/domain/email_services.py @jordyparker
• core/domain/email_subscription_services.py@sahiljoster32
• core/domain/event_services.py
• core/domain/exp_fetchers.py
• core/domain/exp_services.py
• core/domain/expression_parser.py
• core/domain/feedback_services.py
• core/domain/fs_services.py @sahiljoster32
• core/domain/html_cleaner.py @SD-13
• core/domain/html_validation_service.py
• core/domain/image_services.py @gopivaibhav
• core/domain/image_validation_services.py @hsadia538
• core/domain/improvements_services.py
• core/domain/interaction_registry.py
• core/domain/learner_goals_services.py
• core/domain/learner_playlist_services.py
• core/domain/learner_progress_services.py
• core/domain/moderator_services.py
• core/domain/object_registry.py
• core/domain/opportunity_services.py
• core/domain/platform_feature_services.py
• core/domain/platform_parameter_list.py @Darsuu
• core/domain/platform_parameter_list_test.py @Darsuu
• core/domain/platform_parameter_registry.py @Darsuu
• core/domain/playthrough_issue_registry.py @Darsuu
• core/domain/question_fetchers.py @winnie368c
• core/domain/question_services.py
• core/domain/rating_services.py @IamhappyXD
• core/domain/recommendations_services.py
• core/domain/rights_manager.py
• core/domain/role_services.py @gopivaibhav
• core/domain/rte_component_registry.py @hsadia538
• core/domain/rules_registry.py @hsadia538
• core/domain/search_services.py
• core/domain/skill_fetchers.py
• core/domain/skill_services.py
• core/domain/stats_services.py
• core/domain/story_fetchers.py
• core/domain/story_services.py
• core/domain/subscription_services.py
• core/domain/subtopic_page_services.py @ashish-patwal
• core/domain/suggestion_registry.py
• core/domain/suggestion_services.py
• core/domain/summary_services.py
• core/domain/takeout_service.py @jordyparker
• core/domain/taskqueue_services.py @jordyparker
• core/domain/topic_fetchers.py @SD-13
• core/domain/topic_services.py @SD-13
• core/domain/translatable_object_registry.py @ashish-patwal
• core/domain/translation_fetchers.py @sahiljoster32
• core/domain/translation_services.py @sahiljoster32
• core/domain/user_query_services.py @SD-13
• core/domain/user_services.py @SD-13
• core/domain/visualization_registry.py' @SD-13
• core/domain/voiceover_services.py @SD-13
• core/domain/wipeout_service.py @SD-13
• core/domain/change_domain.py @div-yam
• core/domain/collection_domain.py @sahiljoster32
• core/domain/exp_domain.py @Yavnikaa
• core/domain/fs_domain.py @PranshuSrivastava
• core/domain/param_domain.py @Asmit2952 (attempted in #14302)
• core/domain/platform_parameter_domain.py @Asmit2952 (attempted in #14302)
• core/domain/question_domain.py @Asmit2952 (attempted in #14302)
• core/domain/skill_domain.py @dhruvshrivastava
• core/domain/state_domain.py @dhruvshrivastava
• core/domain/stats_domain.py @winnie368c
• core/domain/story_domain.py @Sangkyun-Kim15
• core/domain/subtopic_page_domain.py @ashish-patwal
• core/domain/user_domain.py@sahiljoster32
• core/domain/user_query_domain.py @ashish-patwal

[vojtechjelinek]

Hi @vojtechjelinek , @sajalasati !

I have a question concerning an annotation for the platform_parameter_domain.py file (develop/core/domain/platform_parameter_domain.py ).

I am working on mypy typing but I am getting some trouble with a function that appeared to be recursive: . I am not sure if mypy can handle recursive function properly.

We have defined Mapping as below : Mapping = TypedDict ('Mapping', {'filters' : List[PlatformParameterFilter] , 'value_when_matched' : float })

We got this error : core/domain/platform_parameter_domain.py:556: error: Argument 1 to "from_dict" of "PlatformParameterFilter" has incompatible type "PlatformParameterFilter"; expected "Filter_dict" [arg-type]

Thank you

I think the Mapping is wrong as the value of field with key 'filters' should be List[Dict[…]] or List[SomeTypedDict]]. Also, use more descriptive naming for the TypedDict and use the class installation of TypedDict, so in your case:

class PlatformParameterRuleDict(TypedDict):
    filters: …
    value_when_matched: float

Also, you don’t seem to be assigned to that file, so not sure why are you working on it.

[vojtechjelinek]

I think you should use the alternative syntax for TypedDict’s and define the TypedDicts at a top of a file. So if we have a function that returns {'id': 'abcd', 'active': True, 'count': 1} and represent for example some kind of counter then the type variable should be Counter = TypedDict('Counter', {'id': str, 'active': bool, 'count': int})

Let’s use the class syntax. So if we have a function that returns {'id': 'abcd', 'active': True, 'count': 1} and represent for example some kind of counter then the class should be

class CounterDict(TypedDict)
    id: str
    active: bool
    count: int