[Feature Request] Investigate if we need an unit tests for Python functions created in Rust

[sansyrox]

Current Behavior

Right now, we have zero unit tests.

Desired Behavior

While I am not a big fan of writing unit tests, investigate if there is a need to write any. A potential way would be something like the one below.

use pyo3::prelude::*;

#[derive(Debug, Clone)]
#[pyclass]
pub struct RustStruct {
    #[pyo3(get, set)]
    value: usize,
}

#[pymethods]
impl RustStruct {
    #[new]
    pub fn new(value: usize) -> Self {
        Self { value }
    }
}

#[pymodule]
fn rustlib(_py: Python, m: &PyModule) -> PyResult<()> {
    m.add_class::<RustStruct>()?;
    Ok(())
}



#[cfg(test)]
mod tests {
    use pyo3::{prepare_freethreaded_python, types::PyModule, Python};
    use crate::RustStruct;

    #[test]
    fn test_struct() {
        prepare_freethreaded_python();
        Python::with_gil(|py| {
            const CODE: &str = r#"
from rustlib import RustStruct
def test_fn(value):
    return isinstance(value, RustStruct)
"#;
            let module = PyModule::from_code(py, CODE, "test_mod.py", "test_mod").unwrap();
            let test_fn = module.getattr("test_fn").unwrap();
            let py_res = test_fn.call1((RustStruct::new(12),)).unwrap();
            let res: bool = py_res.extract().unwrap();
            assert!(res); // Fails because the types are not the same
        })
    }

    #[test]
    fn test_struct2() {
        prepare_freethreaded_python();
        Python::with_gil(|py| {
            const CODE: &str = r#"
from rustlib import RustStruct
def test_fn(value):
    return type(value)(13)
"#;
            let module = PyModule::from_code(py, CODE, "test_mod.py", "test_mod").unwrap();
            let test_fn = module.getattr("test_fn").unwrap();
            let py_res = test_fn.call1((RustStruct::new(12),)).unwrap();
            let res: RustStruct = py_res.extract().unwrap();
            assert_eq!(res.value, 13)
        })
    }
}

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Screenshots / Mockups

Alternatives

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[sansyrox]

Not really necessary at the moment.