treaty -


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use macro_rules_attribute::derive;
use treaty::{
    any::{OwnedStatic, TempBorrowedStatic},
    effect::blocking::Blocking,
    protocol::visitor::{tags, visit_sequence, visit_tag, visit_value, TagConst, VisitResult},
    walkers::core::noop::NoopWalker,
    Build, BuildExt as _, Builder, DefaultMode, Flow,
};

use crate::common::{
    protocol::{
        sequence::MockSequenceScope,
        value::{MockValueVisitor, ValueVisitorExt as _},
    },
    walker::MockWalker,
};

mod common;

#[derive(Build!, Debug, PartialEq)]
struct X {
    a: bool,
    b: bool,
}

#[test]
fn a_struct_builder_can_build_from_a_sequence_of_field_values() {
    let mut scope;
    {
        // A tuple-like struct is just a sequence.
        scope = MockSequenceScope::<Blocking>::new();

        // First field.
        scope.expect_next().once().returning(|visitor| {
            // Visit a bool value.
            visitor.visit_value_and_done(OwnedStatic(true));

            // We have another field.
            Flow::Continue
        });

        // Second field.
        scope.expect_next().once().returning(|visitor| {
            // Visit a bool value.
            visitor.visit_value_and_done(OwnedStatic(false));

            // No more fields.
            Flow::Done
        });
    }

    // Make a builder for the struct.
    let mut builder = X::new_builder();

    // Visit the sequence of field values.
    // The struct visitor should report as done.
    assert!(matches!(
        visit_sequence(builder.as_visitor(), &mut scope).value(),
        VisitResult::Control(Flow::Done)
    ));

    // The builder should be able to build a instance of the struct.
    assert_eq!(builder.build().value().unwrap(), X { a: true, b: false });
}

#[test]
fn a_struct_builder_can_build_from_a_sequence_of_keyed_values() {
    let mut scope;
    {
        // A map is a sequence of keyed values.
        scope = MockSequenceScope::<Blocking>::new();

        // Here we do the b field first to show a map-like doesn't care about order.
        scope.expect_next().once().returning(|mut visitor| {
            let mut walker;
            {
                walker = MockWalker::<(), ()>::new();

                // We need to give the b field name in the key tag.
                walker.expect_walk().once().returning(|visitor| {
                    visitor.visit_value_and_done(TempBorrowedStatic("b"));

                    Ok(())
                });
            }

            // Tag the value with a key as the field name.
            assert_eq!(
                visit_tag::<tags::Key, Blocking, _>(TagConst, visitor.cast(), walker).value(),
                Ok(VisitResult::Control(Flow::Continue)),
            );

            // Visit the value as normal.
            visitor.visit_value_and_done(OwnedStatic(true));

            // There is another field.
            Flow::Continue
        });

        // The other field.
        scope.expect_next().once().returning(|mut visitor| {
            let mut walker;
            {
                walker = MockWalker::<(), ()>::new();

                // Here we do field a.
                walker.expect_walk().once().returning(|visitor| {
                    visitor.visit_value_and_done(TempBorrowedStatic("a"));

                    Ok(())
                });
            }

            // Tag the value with a key.
            assert_eq!(
                visit_tag::<tags::Key, Blocking, _>(TagConst, visitor.cast(), walker).value(),
                Ok(VisitResult::Control(Flow::Continue)),
            );

            // The field value.
            visitor.visit_value_and_done(OwnedStatic(false));

            // The sequence protocol allows for us to wait to decide if there is another item.
            Flow::Continue
        });

        // There are no more fields.
        scope.expect_next().once().returning(|_visitor| Flow::Done);
    }

    let mut builder = X::new_builder();

    // We need to provide the map tag to the struct before getting into the sequence.
    // This tag notifies the struct builder to expect the sequence as a map.
    assert_eq!(
        visit_tag::<tags::Map, Blocking, _>(TagConst, builder.as_visitor(), NoopWalker::new())
            .value(),
        Ok(VisitResult::Control(Flow::Continue))
    );

    // Visit the sequence of fields.
    assert_eq!(
        visit_sequence(builder.as_visitor(), &mut scope).value(),
        VisitResult::Control(Flow::Done)
    );

    // The struct is built as the mock walker above makes it.
    assert_eq!(builder.build().value().unwrap(), X { a: false, b: true });
}