Fix for case-insensitive alias matching in InitSettingsSource

[Shindora]

Issue

When using case-insensitive settings with aliases, the InitSettingsSource wasn't correctly matching field aliases in a case-insensitive manner due to not considering case sensitivity when obtaining alias names.

Changes

Modified the __init__ method of InitSettingsSource to pass the case_sensitive parameter to get_alias_names() when generating match aliases
Now properly creates two sets of aliases:

• Canonical aliases (always case-sensitive) for the output key
• Match aliases that respect the configured case sensitivity for matching input values

Add unittest test_init_settings_source_extra_fields_case_sensitive

[hramezani]

Thanks @Shindora for the PR.

Could you please add some examples that don't work with the existing code? You also need to add tests for these changes.

@kschwab do you have time to take a look?

[hramezani]

@Shindora, you've added two tests to the PR, but both pass without your change in base.py

[hramezani]

@Shindora, the 'test_case_sensitive ' test passes without your change in base.py.

[hramezani]

This is the only failing case

    class CaseInsensitiveSettings(BaseSettings):
        foo: str = Field(..., alias='FOO')
        model_config = SettingsConfigDict(case_sensitive=False, extra='allow')

    # Test case-insensitive with extra field
    monkeypatch.setattr(os, 'environ', value={})
    init_kwargs = {'Foo': 'foo_value', 'extra_field': 'extra_value'}
    settings = CaseInsensitiveSettings(**init_kwargs)
    assert settings.foo == 'foo_value'
    assert settings.__pydantic_extra__ == {'extra_field': 'extra_value'}

Please revert your change in test_case_sensitive

cc @kschwab

[Shindora]

This is the only failing case

    class CaseInsensitiveSettings(BaseSettings):
        foo: str = Field(..., alias='FOO')
        model_config = SettingsConfigDict(case_sensitive=False, extra='allow')

    # Test case-insensitive with extra field
    monkeypatch.setattr(os, 'environ', value={})
    init_kwargs = {'Foo': 'foo_value', 'extra_field': 'extra_value'}
    settings = CaseInsensitiveSettings(**init_kwargs)
    assert settings.foo == 'foo_value'
    assert settings.__pydantic_extra__ == {'extra_field': 'extra_value'}

Please revert your change in test_case_sensitive

cc @kschwab

reverted ! I add the new test case to cover my adjustment test_init_settings_source_extra_fields_case_sensitive. Please take a look.

[hramezani]

Thanks @Shindora for the update.

Actually, InitSettingsSource is similar to passing data directly to pydantic. So, I am not sure we want to support case_sensitive in InitSettingsSource. I'm afraid it breaks people's code. Especially, the amount of code change to support this case seems too much to me.

What do you think @kschwab?