facet-reflect 0.46.0

Build and manipulate values of arbitrary Facet types at runtime while respecting invariants - safe runtime reflection
Documentation
use std::sync::Arc;

use facet::Facet;
use facet_reflect::Partial;
use facet_testhelpers::{IPanic, test};

#[derive(Debug, PartialEq, Facet)]
struct Inner {
    value: i32,
}

#[derive(Debug, PartialEq, Facet)]
struct OuterYesArc {
    inner: Arc<Inner>,
}

#[derive(Debug, PartialEq, Facet)]
struct OuterNoArc {
    inner: Inner,
}

#[test]
fn outer_no_arc() {
    let mut partial: Partial<'_> = Partial::alloc::<OuterNoArc>().unwrap();
    partial = partial.begin_field("inner").unwrap();
    partial = partial.begin_field("value").unwrap();
    partial = partial.set(1234_i32).unwrap();
    partial = partial.end().unwrap();
    partial = partial.end().unwrap();
    let o = partial
        .build()
        .unwrap()
        .materialize::<OuterNoArc>()
        .unwrap();
    assert_eq!(
        o,
        OuterNoArc {
            inner: Inner { value: 1234 }
        }
    );
}

#[test]
fn outer_yes_arc_put() {
    let mut partial: Partial<'_> = Partial::alloc::<OuterYesArc>().unwrap();
    let inner = Arc::new(Inner { value: 5678 });
    partial = partial.begin_field("inner").unwrap();
    partial = partial.set(inner.clone()).unwrap();
    partial = partial.end().unwrap();
    let o = partial
        .build()
        .unwrap()
        .materialize::<OuterYesArc>()
        .unwrap();
    assert_eq!(o, OuterYesArc { inner });
}

#[test]
fn outer_yes_arc_pointee() {
    let mut partial: Partial<'_> = Partial::alloc::<OuterYesArc>().unwrap();
    partial = partial.begin_field("inner").unwrap();
    partial = partial.begin_smart_ptr().unwrap();
    partial = partial.begin_field("value").unwrap();
    partial = partial.set(4321_i32).unwrap();
    partial = partial.end().unwrap();
    partial = partial.end().unwrap();
    partial = partial.end().unwrap();
    let o = partial
        .build()
        .unwrap()
        .materialize::<OuterYesArc>()
        .unwrap();
    assert_eq!(
        o,
        OuterYesArc {
            inner: Arc::new(Inner { value: 4321 })
        }
    );
}

#[test]
fn outer_yes_arc_field_named_twice_error() {
    let mut partial: Partial<'_> = Partial::alloc::<OuterYesArc>().unwrap();
    partial = partial.begin_field("inner").unwrap();
    // Try to do begin_field again instead of begin_smart_ptr; this should error
    let err = partial.begin_field("value").err().unwrap();
    let err_string = format!("{err}");
    assert!(
        err_string.contains("opaque types cannot be reflected upon"),
        "Error message should mention 'opaque types cannot be reflected upon', got: {err_string}"
    );
}

#[test]
fn arc_str_begin_smart_ptr_good() {
    let mut partial = Partial::alloc::<Arc<str>>().unwrap();
    partial = partial.begin_smart_ptr().unwrap();
    partial = partial.set(String::from("foobar")).unwrap();
    partial = partial.end().unwrap();
    let built = partial.build().unwrap().materialize::<Arc<str>>().unwrap();
    assert_eq!(&*built, "foobar");
}

#[test]
fn arc_str_begin_smart_ptr_bad_1() {
    let partial = Partial::alloc::<Arc<str>>().unwrap();
    let _err = partial.build().unwrap_err();
    #[cfg(not(miri))]
    insta::assert_snapshot!(_err);
}

#[test]
fn arc_str_begin_smart_ptr_bad_2a() {
    let mut partial = Partial::alloc::<Arc<str>>().unwrap();
    partial = partial.begin_smart_ptr().unwrap();
    let _err = partial.build().unwrap_err();
    #[cfg(not(miri))]
    insta::assert_snapshot!(_err);
}

#[test]
fn arc_str_begin_smart_ptr_bad_2b() {
    let mut partial = Partial::alloc::<Arc<str>>().unwrap();
    partial = partial.begin_smart_ptr().unwrap();
    let _err = match partial.end() {
        Ok(_) => panic!("expected error"),
        Err(e) => e,
    };
    #[cfg(not(miri))]
    insta::assert_snapshot!(_err);
}

#[test]
fn arc_str_begin_smart_ptr_bad_3() {
    let mut partial = Partial::alloc::<Arc<str>>().unwrap();
    partial = partial.begin_smart_ptr().unwrap();
    partial = partial.set(String::from("foobar")).unwrap();
    let _err = partial.build().unwrap_err();
    #[cfg(not(miri))]
    insta::assert_snapshot!(_err);
}

#[test]
fn rc_str_begin_smart_ptr_once() {
    use std::rc::Rc;
    let mut partial = Partial::alloc::<Rc<str>>().unwrap();
    partial = partial.begin_smart_ptr().unwrap();
    partial = partial.set(String::from("foobar")).unwrap();
    partial = partial.end().unwrap();
    let built = partial
        .build()
        .unwrap()
        .materialize::<std::rc::Rc<str>>()
        .unwrap();
    assert_eq!(&*built, "foobar");
}

#[test]
fn rc_str_begin_smart_ptr_twice() -> Result<(), IPanic> {
    use std::rc::Rc;
    let mut partial = Partial::alloc::<Rc<str>>()?;

    eprintln!("==== first go");
    partial = partial.begin_smart_ptr()?;
    partial = partial.set(String::from("foobar"))?;
    partial = partial.end()?;

    eprintln!("==== second go");
    partial = partial.begin_smart_ptr()?;
    partial = partial.set(String::from("barbaz"))?;
    partial = partial.end()?;

    eprintln!("==== build");
    let built = partial.build()?.materialize::<std::rc::Rc<str>>()?;
    assert_eq!(&*built, "barbaz");

    Ok(())
}

#[test]
fn box_str_begin_smart_ptr() {
    let mut partial = Partial::alloc::<Box<str>>().unwrap();
    partial = partial.begin_smart_ptr().unwrap();
    partial = partial.set(String::from("foobar")).unwrap();
    partial = partial.end().unwrap();
    let built = partial.build().unwrap().materialize::<Box<str>>().unwrap();
    assert_eq!(&*built, "foobar");
}

#[test]
fn arc_slice_u8_begin_smart_ptr_good() {
    {
        // Just to make sure: Vec<u8> construction works
        let mut partial = Partial::alloc::<Vec<u8>>().unwrap();
        partial = partial.init_list().unwrap();
        partial = partial.push(2_u8).unwrap();
        partial = partial.push(3_u8).unwrap();
        partial = partial.push(4_u8).unwrap();
        let built = partial.build().unwrap().materialize::<Vec<u8>>().unwrap();
        assert_eq!(&*built, &[2, 3, 4]);
    }

    {
        // Now, does Arc<[u8]> work.unwrap()
        let mut partial = Partial::alloc::<Arc<[u8]>>().unwrap();
        partial = partial.begin_smart_ptr().unwrap();
        partial = partial.init_list().unwrap();
        partial = partial.push(2_u8).unwrap();
        partial = partial.push(3_u8).unwrap();
        partial = partial.push(4_u8).unwrap();
        partial = partial.end().unwrap();
        let built = partial.build().unwrap().materialize::<Arc<[u8]>>().unwrap();
        assert_eq!(&*built, &[2, 3, 4]);
    }
}

// =============================================================================
// Tests migrated from src/partial/tests.rs
// =============================================================================

#[cfg(not(miri))]
macro_rules! assert_snapshot {
    ($($tt:tt)*) => {
        insta::assert_snapshot!($($tt)*)
    };
}
#[cfg(miri)]
macro_rules! assert_snapshot {
    ($($tt:tt)*) => {{ let _ = $($tt)*; }};
}

#[test]
fn box_init() -> Result<(), IPanic> {
    let hv = Partial::alloc::<Box<u32>>()?
        // Push into the Box to build its inner value
        .begin_smart_ptr()?
        .set(42u32)?
        .end()?
        .build()?
        .materialize::<Box<u32>>()?;
    assert_eq!(*hv, 42);
    Ok(())
}

#[test]
fn box_partial_init() -> Result<(), IPanic> {
    // Don't initialize the Box at all
    assert_snapshot!(Partial::alloc::<Box<u32>>()?.build().unwrap_err());
    Ok(())
}

#[test]
fn box_struct() -> Result<(), IPanic> {
    #[derive(Facet, Debug, PartialEq)]
    struct Point {
        x: f64,
        y: f64,
    }

    let hv = Partial::alloc::<Box<Point>>()?
        // Push into the Box
        .begin_smart_ptr()?
        // Build the Point inside the Box using set_field shorthand
        .set_field("x", 1.0)?
        .set_field("y", 2.0)?
        // end from Box
        .end()?
        .build()?
        .materialize::<Box<Point>>()?;
    assert_eq!(*hv, Point { x: 1.0, y: 2.0 });
    Ok(())
}

#[test]
fn drop_box_partially_initialized() -> Result<(), IPanic> {
    use core::sync::atomic::{AtomicUsize, Ordering};
    static BOX_DROP_COUNT: AtomicUsize = AtomicUsize::new(0);
    static INNER_DROP_COUNT: AtomicUsize = AtomicUsize::new(0);

    #[derive(Facet, Debug)]
    struct DropCounter {
        value: u32,
    }

    impl Drop for DropCounter {
        fn drop(&mut self) {
            INNER_DROP_COUNT.fetch_add(1, Ordering::SeqCst);
            println!("Dropping DropCounter with value: {}", self.value);
        }
    }

    BOX_DROP_COUNT.store(0, Ordering::SeqCst);
    INNER_DROP_COUNT.store(0, Ordering::SeqCst);

    {
        let mut partial = Partial::alloc::<Box<DropCounter>>()?;

        // Initialize the Box's inner value using set
        partial = partial.begin_smart_ptr()?;
        partial = partial.set(DropCounter { value: 99 })?;
        let _partial = partial.end()?;

        // Drop the partial - should drop the Box which drops the inner value
    }

    assert_eq!(
        INNER_DROP_COUNT.load(Ordering::SeqCst),
        1,
        "Should drop the inner value through Box's drop"
    );
    Ok(())
}

#[test]
fn arc_init() -> Result<(), IPanic> {
    let hv = Partial::alloc::<Arc<u32>>()?
        // Push into the Arc to build its inner value
        .begin_smart_ptr()?
        .set(42u32)?
        .end()?
        .build()?
        .materialize::<Arc<u32>>()?;
    assert_eq!(*hv, 42);
    Ok(())
}

#[test]
fn arc_partial_init() -> Result<(), IPanic> {
    // Don't initialize the Arc at all
    assert_snapshot!(Partial::alloc::<Arc<u32>>()?.build().unwrap_err());
    Ok(())
}

#[test]
fn arc_struct() -> Result<(), IPanic> {
    #[derive(Facet, Debug, PartialEq)]
    struct Point {
        x: f64,
        y: f64,
    }

    let hv = Partial::alloc::<Arc<Point>>()?
        // Push into the Arc
        .begin_smart_ptr()?
        // Build the Point inside the Arc using set_field shorthand
        .set_field("x", 3.0)?
        .set_field("y", 4.0)?
        // end from Arc
        .end()?
        .build()?
        .materialize::<Arc<Point>>()?;
    assert_eq!(*hv, Point { x: 3.0, y: 4.0 });
    Ok(())
}

#[test]
fn drop_arc_partially_initialized() -> Result<(), IPanic> {
    use core::sync::atomic::{AtomicUsize, Ordering};
    static INNER_DROP_COUNT: AtomicUsize = AtomicUsize::new(0);

    #[derive(Facet, Debug)]
    struct DropCounter {
        value: u32,
    }

    impl Drop for DropCounter {
        fn drop(&mut self) {
            INNER_DROP_COUNT.fetch_add(1, Ordering::SeqCst);
            println!("Dropping DropCounter with value: {}", self.value);
        }
    }

    INNER_DROP_COUNT.store(0, Ordering::SeqCst);

    {
        let mut partial = Partial::alloc::<Arc<DropCounter>>()?;

        // Initialize the Arc's inner value
        partial = partial.begin_smart_ptr()?;
        partial = partial.set(DropCounter { value: 123 })?;
        let _partial = partial.end()?;

        // Drop the partial - should drop the Arc which drops the inner value
    }

    assert_eq!(
        INNER_DROP_COUNT.load(Ordering::SeqCst),
        1,
        "Should drop the inner value through Arc's drop"
    );
    Ok(())
}