fix: skip empty choice value

[fabien-michel]

Seems they are not supported by GraphQL

Having an empty choice make generate enum from choice feature crash, trying to use None as a string.

class Choice(models.TextChoices):
    A = "a", "A description"
    B = "b", "B description"
    __empty__ =  "Empty"

Description

The fix, for now, is to skip empty value, so the behavior is the same as TextChoiceField.
It make the schema building pass, but sadly, data with an empty value will still fail with Enum 'MyAutoGeneratedEnum' cannot represent value: '' and I'm note sure what to do with that.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Documentation

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

Summary by Sourcery

Bug Fixes:

• Prevent crashes when generating enums from choices with empty values by skipping them.

[sourcery-ai]

Reviewer's Guide by Sourcery

This pull request fixes a bug where empty choice values in Django models were causing crashes when generating enums. The fix skips empty choice values during enum generation, aligning the behavior with TextChoiceField.

Sequence diagram for enum generation with empty choice handling

sequenceDiagram
    participant Django as Django Model Field
    participant Resolver as Field Type Resolver
    participant GraphQL as GraphQL Schema

    Django->>Resolver: Get choices from model field
    activate Resolver
    loop For each choice
        alt Choice value is empty
            Resolver-->>Resolver: Skip empty choice
        else Choice value is not empty
            Resolver->>Resolver: Convert choice to GraphQL enum
            Note right of Resolver: Clean name using regex
        end
    end
    Resolver->>GraphQL: Return enum type
    deactivate Resolver

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Class diagram showing Choice model changes

classDiagram
    class Choice {
        <<TextChoices>>
        +A: str
        +B: str
        +__empty__: str
        +get_choices()
    }
    note for Choice "Empty choices are now skipped
during GraphQL enum generation"

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File-Level Changes

Change	Details	Files
Skip empty choice values during enum generation.	Added a condition to skip empty choice values in the resolve_model_field_type function. Added a test case for empty choice values in the test_enums.py file. Modified the type hint for choices to include `str	None` to handle empty choices correctly.

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[sourcery-ai]

Hey @fabien-michel - I've reviewed your changes - here's some feedback:

Overall Comments:

• You've marked that this change requires documentation updates, but no documentation changes were made. Please update the documentation to reflect that empty choices are skipped in GraphQL enum generation.

Here's what I looked at during the review

• 🟢 General issues: all looks good
• 🟢 Security: all looks good
• 🟢 Testing: all looks good
• 🟢 Complexity: all looks good
• 🟢 Documentation: all looks good

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[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.01%. Comparing base (0b28264) to head (ecdaa64).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #687   +/-   ##
=======================================
  Coverage   89.00%   89.01%           
=======================================
  Files          42       42           
  Lines        3821     3823    +2     
=======================================
+ Hits         3401     3403    +2     
  Misses        420      420           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[fabien-michel]

Hmm, seems the problem is more than that.
Having object with an enum field value set to empty string, make GraphQL fail with Enum 'MyAutoGeneratedEnum' cannot represent value: ''

I'm not sure what to do here.

[bellini666]

Ty! :)