Add validated data args in default factory

[nix010]

Change Summary

Add feature pydantic pydantic/pydantic#9789

Related issue number

Checklist

• Unit tests for the changes exist
• Documentation reflects the changes where applicable
• Pydantic tests pass with this pydantic-core (except for expected changes)
• My PR is ready to review, please add a comment including the phrase "please review" to assign reviewers

Selected Reviewer: @davidhewitt

[nix010]

Open to suggestions on better way to do args checking on the python default factory!

[codecov]

Codecov Report

Attention: Patch coverage is 93.75000% with 1 line in your changes missing coverage. Please review.

Project coverage is 89.21%. Comparing base (ab503cb) to head (ecbc7a9).
Report is 190 commits behind head on main.

Files with missing lines	Patch %	Lines
src/validators/with_default.rs	93.33%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1475      +/-   ##
==========================================
- Coverage   90.21%   89.21%   -1.00%     
==========================================
  Files         106      112       +6     
  Lines       16339    17829    +1490     
  Branches       36       41       +5     
==========================================
+ Hits        14740    15906    +1166     
- Misses       1592     1903     +311     
- Partials        7       20      +13     

Files with missing lines	Coverage Δ
src/serializers/type_serializers/with_default.rs	79.06% <100.00%> (ø)
src/validators/with_default.rs	98.38% <93.33%> (-0.69%)	⬇️

... and 48 files with indirect coverage changes

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[codspeed-hq]

CodSpeed Performance Report

Merging #1475 will not alter performance

_{Comparing nix010:add_validated_data_arg_to_default_factory (ecbc7a9) with main (903a1a9)}

Summary

✅ 155 untouched benchmarks

[nix010]

please review

[sydney-runkle]

This implementation is more simple than I expected thus far - nice work.

Curious to hear what @Viicos thinks given that he helped with the design choices for this API.

[sydney-runkle]

Should we add both branches here so that we can hopefully remove the hack in the long run?

See

pydantic-core/src/input/return_enums.rs

Lines 313 to 327 in 903a1a9

	// the PyFunction::is_type_of(attr) catches `staticmethod`, but also any other function,
	// I think that's better than including static methods in the yielded attributes,
	// if someone really wants fields, they can use an explicit field, or a function to modify input
	#[cfg(not(PyPy))]
	if !is_bound && !attr.is_instance_of::<PyFunction>() {
	return Some(Ok((name, attr)));
	}
	// MASSIVE HACK! PyFunction doesn't exist for PyPy,
	// is_instance_of::<PyFunction> crashes with a null pointer, hence this hack, see
	// https://github.com/pydantic/pydantic-core/pull/161#discussion_r917257635
	#[cfg(PyPy)]
	if !is_bound && attr.get_type().to_string() != "<class 'function'>" {
	return Some(Ok((name, attr)));
	}
	}

for an example.

[sydney-runkle]

Do we even need the function check here? I assume if we got to this point we know this is a callable bc we've matched on DefaultFactory...

[nix010]

Yes, because there's a case ex: default_factory=str in python then the default_factory here will not have __code__ and raise error.

[Viicos]

Thanks @nix010 for the implementation.

The proper way (and this will simplify things even more here) to do this is to inspect the default_factory callable in Pydantic, using inspect. The core schema structure will have to be changed to add a new has_values_arg boolean entry (name TBD).

As an existing example, we do this in pydantic._internal.decorators.inspect_validator to determine if validators take the info argument or not.

[nix010]

Thanks @nix010 for the implementation.

The proper way (and this will simplify things even more here) to do this is to inspect the default_factory callable in Pydantic, using inspect. The core schema structure will have to be changed to add a new has_values_arg boolean entry (name TBD).

As an existing example, we do this in pydantic._internal.decorators.inspect_validator to determine if validators take the info argument or not.

@Viicos So my intention is exactly the same. But to inspect the function within fn default_value(), I went with the __code__ attr there. Can you advise me on a better way to do that?

[sydney-runkle]

@Viicos is referring to https://github.com/pydantic/pydantic/blob/6c3d3b3bb255422fc64eec8e9014016743207ff0/pydantic/_internal/_decorators.py#L514-L548

Basically, we want to inspect the function in pydantic with the inspect module, then modify the core schema accordingly (we'll have to add an argument). We can match on that argument to decide on whether we need to pass the validated data, in pydantic-core.

[nix010]

So my intention is exactly the same. But to inspect the function within fn default_value(), I went with the __code__ attr there. Can you advise me on a better way to do that?

Ok. So there will be a bool var in the model core schema to flag if the data need to pass in to the default_factory or not. Right ?

[Viicos]

Ok. So there will be a bool var in the model core schema to flag if the data need to pass in to the default_factory or not. Right ?

Correcet, probably on the field core schema