django-stubs: Fix Promise related typing errors.

[PIG208]

This discussion for this solution can be found here.

gettext_lazy returns Promise objects that is actually different from str. Methods that are present on str can also be accessed on such objects. And it behaves like a str except that it is not an instance of str.

Affected errors:

3c3
< Found 86 errors in 31 files (checked 1406 source files)
---
> Found 48 errors in 24 files (checked 1406 source files)
5,6d4
< corporate/lib/stripe.py error "Promise" has no attribute "format"  [attr-defined]
< corporate/lib/stripe_event_handler.py error "Promise" has no attribute "format"  [attr-defined]
8,15d5
< corporate/views/upgrade.py error "Promise" has no attribute "format"  [attr-defined]
< zerver/actions/message_edit.py error Argument 4 to "send_message_moved_breadcrumbs" has incompatible type "Optional[Promise]"; expected "Optional[str]"  [arg-type]
< zerver/actions/message_edit.py error Argument 7 to "send_message_moved_breadcrumbs" has incompatible type "Optional[Promise]"; expected "Optional[str]"  [arg-type]
< zerver/actions/streams.py error Argument 3 to "internal_send_stream_message" has incompatible type "Promise"; expected "str"  [arg-type]
< zerver/actions/streams.py error Argument 3 to "internal_send_stream_message" has incompatible type "Promise"; expected "str"  [arg-type]
< zerver/actions/streams.py error Argument 3 to "internal_send_stream_message" has incompatible type "Promise"; expected "str"  [arg-type]
< zerver/actions/streams.py error Argument 3 to "internal_send_stream_message" has incompatible type "Promise"; expected "str"  [arg-type]
< zerver/actions/streams.py error Argument 3 to "internal_send_stream_message" has incompatible type "Promise"; expected "str"  [arg-type]
21,23d10
< zerver/forms.py error Argument 1 to "ValidationError" has incompatible type "Promise"; expected "Union[str, ValidationError, Dict[str, Any], List[Any]]"  [arg-type]
< zerver/forms.py error Argument 1 to "ValidationError" has incompatible type "Promise"; expected "Union[str, ValidationError, Dict[str, Any], List[Any]]"  [arg-type]
< zerver/forms.py error "Promise" has no attribute "format"  [attr-defined]
57d28
< zerver/models.py error Argument "message" to "RegexValidator" has incompatible type "Promise"; expected "Optional[str]"  [arg-type]
61d31
< zerver/models.py error Incompatible return value type (got "Promise", expected "str")  [return-value]
65,68d34
< zerver/models.py error Dict entry 0 has incompatible type "int" "Promise"; expected "int" "str"  [dict-item]
< zerver/models.py error Dict entry 1 has incompatible type "int" "Promise"; expected "int" "str"  [dict-item]
< zerver/models.py error Dict entry 2 has incompatible type "int" "Promise"; expected "int" "str"  [dict-item]
< zerver/models.py error Dict entry 3 has incompatible type "int" "Promise"; expected "int" "str"  [dict-item]
71d36
< zerver/models.py error Argument 1 to "JsonableError" has incompatible type "Promise"; expected "str"  [arg-type]
81d45
< zerver/views/auth.py error "Promise" has no attribute "format"  [attr-defined]
84,85d47
< zerver/views/streams.py error Argument "topic" to "internal_prep_stream_message" has incompatible type "Promise"; expected "str"  [arg-type]
< zerver/views/users.py error Argument 1 to "JsonableError" has incompatible type "Promise"; expected "str"  [arg-type]

Screenshots and screen captures:

Self-review checklist

• Self-reviewed the changes for clarity and maintainability
  (variable names, code reuse, readability, etc.).

Communicate decisions, questions, and potential concerns.

• Explains differences from previous plans (e.g., issue description).
• Highlights technical choices and bugs encountered.
• Calls out remaining decisions and concerns.
• Automated tests verify logic where appropriate.

Individual commits are ready for review (see commit discipline).

• Each commit is a coherent idea.
• Commit message(s) explain reasoning and motivation for changes.

Completed manual review and testing of the following:

• Visual appearance of the changes.
• Responsiveness and internationalization.
• Strings and tooltips.
• End-to-end functionality of buttons, interactions and flows.
• Corner cases, error conditions, and easily imagined bugs.

[andersk]

This is mostly blocked on

• Return Promise for lazy functions. typeddjango/django-stubs#689,

but if you’d like to move the import fix into a new PR, that might be worth merging sooner.

[PIG208]

The above mentioned issue with the validator is fixed in 18a055124a2212e13c97bc1a83cc36b4e8104a97, along with the implementation of _StrPromise in django-stubs.

[timabbott]

Merged, thanks @PIG208!