schemars/src/make_schema.rs

use crate::schema::*;
use serde_json::json;
use std::collections::BTreeMap as Map;

pub trait MakeSchema {
    fn make_schema() -> Schema;
}

// TODO structs, enums, tuples

// TODO serde json value, any other serde values?
// https://github.com/serde-rs/serde/blob/ce75418e40a593fc5c0902cbf4a45305a4178dd7/serde/src/ser/impls.rs
// Cell<T>, RefCell<T>, Mutex<T>, RwLock<T>, Result<R,E>?, Duration, SystemTime,
// IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV6, SocketAddrV6,
// Path, PathBuf, OsStr, OsString, Wrapping<T>, Reverse<T>, AtomicBool, AtomixI8 etc.,
// NonZeroU8 etc., ArcWeak, RcWeak, BTreeMap, HashMap, unit?, (!)?, Bound?, Range?, RangeInclusive?,
// PhantomData?, CString?, CStr?, fmt::Arguments?
// !map keys must be Into<String>!

////////// PRIMITIVES (except ints) //////////

macro_rules! simple_impl {
    ($type:ident => $instance_type:expr) => {
        impl MakeSchema for $type {
            fn make_schema() -> Schema {
                Schema {
                    instance_type: Some($instance_type.into()),
                    ..Default::default()
                }
            }
        }
    };
}

simple_impl!(str => InstanceType::String);
simple_impl!(String => InstanceType::String);
simple_impl!(bool => InstanceType::Boolean);
simple_impl!(f32 => InstanceType::Number);
simple_impl!(f64 => InstanceType::Number);

impl MakeSchema for char {
    fn make_schema() -> Schema {
        let mut extra_properties = Map::new();
        extra_properties.insert("minLength".to_owned(), json!(1));
        extra_properties.insert("maxLength".to_owned(), json!(1));
        Schema {
            instance_type: Some(InstanceType::String.into()),
            extra_properties,
            ..Default::default()
        }
    }
}

////////// INTS //////////

macro_rules! int_impl {
    ($type:ident) => {
        impl MakeSchema for $type {
            fn make_schema() -> Schema {
                let mut extra_properties = Map::new();
                // this may be overkill...
                extra_properties.insert("minimum".to_owned(), json!($type::min_value()));
                extra_properties.insert("maximum".to_owned(), json!($type::max_value()));
                Schema {
                    instance_type: Some(InstanceType::Integer.into()),
                    extra_properties,
                    ..Default::default()
                }
            }
        }
    };
}

int_impl!(i8);
int_impl!(i16);
int_impl!(i32);
int_impl!(i64);
int_impl!(i128);
int_impl!(isize);
int_impl!(u8);
int_impl!(u16);
int_impl!(u32);
int_impl!(u64);
int_impl!(u128);
int_impl!(usize);

////////// ARRAYS //////////

// Does not require T: MakeSchema.
impl<T> MakeSchema for [T; 0] {
    fn make_schema() -> Schema {
        let mut extra_properties = Map::new();
        extra_properties.insert("maxItems".to_owned(), json!(0));
        Schema {
            instance_type: Some(InstanceType::Array.into()),
            extra_properties,
            ..Default::default()
        }
    }
}

macro_rules! array_impls {
    ($($len:tt)+) => {
        $(
            impl<T: MakeSchema> MakeSchema for [T; $len]
            {
                fn make_schema() -> Schema {
                    let mut extra_properties = Map::new();
                    extra_properties.insert("minItems".to_owned(), json!($len));
                    extra_properties.insert("maxItems".to_owned(), json!($len));
                    Schema {
                        instance_type: Some(InstanceType::Array.into()),
                        items: Some(Box::from(T::make_schema())),
                        extra_properties,
                        ..Default::default()
                    }
                }
            }
        )+
    }
}

array_impls! {
    01 02 03 04 05 06 07 08 09 10
    11 12 13 14 15 16 17 18 19 20
    21 22 23 24 25 26 27 28 29 30
    31 32
}

////////// SEQUENCES /////////

macro_rules! seq_impl {
    ($($desc:tt)+) => {
        impl $($desc)+
        where
            T: MakeSchema,
        {
            fn make_schema() -> Schema
            {
                Schema {
                    instance_type: Some(InstanceType::Array.into()),
                    items: Some(Box::from(T::make_schema())),
                    ..Default::default()
                }
            }
        }
    };
}

seq_impl!(<T: Ord> MakeSchema for std::collections::BinaryHeap<T>);
seq_impl!(<T: Ord> MakeSchema for std::collections::BTreeSet<T>);
seq_impl!(<T: Eq + core::hash::Hash, H: core::hash::BuildHasher> MakeSchema for std::collections::HashSet<T, H>);
seq_impl!(<T> MakeSchema for std::collections::LinkedList<T>);
seq_impl!(<T> MakeSchema for Vec<T>);
seq_impl!(<T> MakeSchema for std::collections::VecDeque<T>);

////////// OPTION //////////

impl<T: MakeSchema> MakeSchema for Option<T> {
    fn make_schema() -> Schema {
        let mut schema = T::make_schema();
        if let Some(instance_type) = schema.instance_type {
            let mut vec: Vec<_> = instance_type.into();
            if !vec.contains(&InstanceType::Null) {
                vec.push(InstanceType::Null);
            }
            schema.instance_type = Some(vec.into());
        }
        schema
    }
}

////////// DEREF //////////

macro_rules! deref_impl {
    ($($desc:tt)+) => {
        impl $($desc)+
        where
            T: ?Sized + MakeSchema,
        {
            fn make_schema() -> Schema {
                T::make_schema()
            }
        }
    };
}

deref_impl!(<'a, T> MakeSchema for &'a T);
deref_impl!(<'a, T> MakeSchema for &'a mut T);
deref_impl!(<T> MakeSchema for Box<T>);
deref_impl!(<T> MakeSchema for std::rc::Rc<T>);
deref_impl!(<T> MakeSchema for std::sync::Arc<T>);
deref_impl!(<'a, T: ToOwned> MakeSchema for std::borrow::Cow<'a, T>);