Derive Macro async_graphql::NewType

#[derive(NewType)]
{
    // Attributes available to this derive:
    #[graphql]
}

Define a NewType Scalar

It also implements From<InnerType> and Into<InnerType>.

Macro parameters

Attribute	description	Type	Optional
name	If this attribute is provided then define a new scalar, otherwise it is just a transparent proxy for the internal scalar.	string	Y
name	If this attribute is provided then define a new scalar, otherwise it is just a transparent proxy for the internal scalar.	bool	Y
visible(Only valid for new scalars.)	If false, it will not be displayed in introspection. See also the Book.	bool	Y
visible(Only valid for new scalars.)	Call the specified function. If the return value is false, it will not be displayed in introspection.	string	Y

Examples

Use the original scalar name

use async_graphql::*;

#[derive(NewType)]
struct Weight(f64);

struct QueryRoot;

#[Object]
impl QueryRoot {
    async fn value(&self) -> Weight {
        Weight(1.234)
    }
}

// Test conversion
let weight: Weight = 10f64.into();
let weight_f64: f64 = weight.into();

tokio::runtime::Runtime::new().unwrap().block_on(async move {
    let schema = Schema::build(QueryRoot, EmptyMutation, EmptySubscription).data("hello".to_string()).finish();

    let res = schema.execute("{ value }").await.into_result().unwrap().data;
    assert_eq!(res, value!({
        "value": 1.234,
    }));

    let res = schema.execute(r#"
    {
        __type(name: "QueryRoot") {
            fields {
                name type {
                    kind
                    ofType { name }
                }
            }
        }
    }"#).await.into_result().unwrap().data;
    assert_eq!(res, value!({
        "__type": {
            "fields": [{
                "name": "value",
                "type": {
                    "kind": "NON_NULL",
                    "ofType": {
                        "name": "Float"
                    }
                }
            }]
        }
    }));
});

Define a new scalar

use async_graphql::*;

/// Widget NewType
#[derive(NewType)]
#[graphql(name)] // or: #[graphql(name = true)], #[graphql(name = "Weight")]
struct Weight(f64);

struct QueryRoot;

#[Object]
impl QueryRoot {
    async fn value(&self) -> Weight {
        Weight(1.234)
    }
}

tokio::runtime::Runtime::new().unwrap().block_on(async move {
    let schema = Schema::build(QueryRoot, EmptyMutation, EmptySubscription).data("hello".to_string()).finish();

    let res = schema.execute("{ value }").await.into_result().unwrap().data;
    assert_eq!(res, value!({
        "value": 1.234,
    }));

    let res = schema.execute(r#"
    {
        __type(name: "QueryRoot") {
            fields {
                name type {
                    kind
                    ofType { name }
                }
            }
        }
    }"#).await.into_result().unwrap().data;
    assert_eq!(res, value!({
        "__type": {
            "fields": [{
                "name": "value",
                "type": {
                    "kind": "NON_NULL",
                    "ofType": {
                        "name": "Weight"
                    }
                }
            }]
        }
    }));

    assert_eq!(schema.execute(r#"{ __type(name: "Weight") { name description } }"#).
        await.into_result().unwrap().data, value!({
            "__type": {
                "name": "Weight", "description": "Widget NewType"
            }
        }));
});