wip-rs/crates/wip-interface/tests/codecs.rs

use wip_interface::wip_protocol::{
    EnumDeclaration, JsonMember, JsonValue, NamedValue, RecordDeclaration, TypeDeclaration,
    TypeExpr, UnionDeclaration, Value,
};
use wip_interface::{Bytes, Entry, WipType};

/// A request record.
#[derive(Debug, Clone, PartialEq, WipType)]
struct Request {
    /// Required title.
    title: String,
    /// Optional priority.
    priority: Option<i32>,
    /// Related entries.
    related: Vec<Entry<String, bool>>,
    /// Opaque bytes.
    body: Bytes,
    /// Arbitrary metadata.
    metadata: JsonValue,
}

/// Available colors.
#[derive(Debug, Clone, PartialEq, WipType)]
enum Color {
    /// Warm red.
    Red,
    /// Cool blue.
    Blue,
}

/// A receipt record.
#[derive(Debug, Clone, PartialEq, WipType)]
struct Receipt {
    /// Receipt number.
    number: u32,
}

/// Application-level publication outcome.
#[derive(Debug, Clone, PartialEq, WipType)]
enum PublishOutcome {
    /// Application success.
    Published(Receipt),
    /// Domain rejection, not a host failure.
    Rejected(String),
}

#[test]
fn supported_values_round_trip() {
    let request = Request {
        title: "hello".into(),
        priority: None,
        related: vec![Entry {
            key: "/articles/1".into(),
            value: true,
        }],
        body: Bytes(vec![1, 2, 3]),
        metadata: JsonValue::Object(vec![JsonMember {
            name: "source".into(),
            value: JsonValue::String("test".into()),
        }]),
    };

    let encoded = request.clone().encode().unwrap();
    let Value::Record(fields) = &encoded else {
        panic!("record derive must encode a protocol record")
    };
    assert!(fields.iter().all(|field| field.name != "priority"));
    assert_eq!(Request::decode(encoded).unwrap(), request);

    let number = 42.5_f64;
    assert_eq!(f64::type_expr(), TypeExpr::Number);
    assert_eq!(f64::decode(number.encode().unwrap()).unwrap(), number);

    let narrow_number = 1.5_f32;
    assert_eq!(f32::type_expr(), TypeExpr::Number);
    assert_eq!(
        f32::decode(narrow_number.encode().unwrap()).unwrap(),
        narrow_number
    );

    for color in [Color::Red, Color::Blue] {
        let encoded = color.clone().encode().unwrap();
        let decoded = Color::decode(encoded).unwrap();
        assert_eq!(decoded, color);
    }

    for outcome in [
        PublishOutcome::Published(Receipt { number: 7 }),
        PublishOutcome::Rejected("policy".into()),
    ] {
        let encoded = outcome.clone().encode().unwrap();
        let decoded = PublishOutcome::decode(encoded).unwrap();
        assert_eq!(decoded, outcome);
    }
}

#[test]
fn derived_declarations_include_docs_optionality_and_dependencies() {
    let mut declarations = Vec::new();
    Request::collect_declarations(&mut declarations);
    Color::collect_declarations(&mut declarations);
    PublishOutcome::collect_declarations(&mut declarations);

    let TypeDeclaration::Record(RecordDeclaration {
        documentation,
        fields,
        ..
    }) = &declarations[0]
    else {
        panic!("Request must be a record declaration")
    };
    assert_eq!(documentation.as_ref().unwrap().summary, "A request record.");
    assert_eq!(
        fields[0].documentation.as_ref().unwrap().summary,
        "Required title."
    );
    assert!(!fields[0].optional);
    assert!(fields[1].optional);
    assert_eq!(fields[1].ty, TypeExpr::Integer);
    assert_eq!(
        fields[2].ty,
        TypeExpr::List(Box::new(TypeExpr::Entry {
            key: Box::new(TypeExpr::String),
            value: Box::new(TypeExpr::Boolean),
        }))
    );

    let color = declarations
        .iter()
        .find(|declaration| declaration.name() == "Color")
        .unwrap();
    let TypeDeclaration::Enum(EnumDeclaration { variants, .. }) = color else {
        panic!("Color must be an enum declaration")
    };
    assert_eq!(
        variants[0].documentation.as_ref().unwrap().summary,
        "Warm red."
    );

    let outcome = declarations
        .iter()
        .find(|declaration| declaration.name() == "PublishOutcome")
        .unwrap();
    let TypeDeclaration::Union(UnionDeclaration { variants, .. }) = outcome else {
        panic!("PublishOutcome must be a union declaration")
    };
    assert_eq!(variants[0].ty, TypeExpr::Named("Receipt".into()));
    assert!(
        declarations
            .iter()
            .any(|declaration| declaration.name() == "Receipt")
    );
}

#[test]
fn codecs_reject_invalid_boundaries() {
    assert!(i64::MAX.encode().is_err());
    assert!(f64::NAN.encode().is_err());
    assert!(Request::decode(Value::Record(vec![])).is_err());
    assert!(
        Request::decode(Value::Record(vec![NamedValue {
            name: "unknown".into(),
            value: Value::String("value".into()),
        }]))
        .is_err()
    );
    assert!(Color::decode(Value::Enum("Green".into())).is_err());
}