axum-async-graphql/src/scalar.rs

use async_graphql::*;
use sqlx::{
    postgres::{PgArgumentBuffer, PgHasArrayType, PgTypeInfo, PgValueRef},
    Decode, Encode, Postgres, Type,
};
use ulid::Ulid as UlidPrimitive;

pub type Time = chrono::DateTime<chrono::Utc>;

/// The ID scalar type represents a unique identifier, often used to refetch an object or as key for a cache.
/// The ID type appears in a JSON response as a String; however, it is not intended to be human-readable.
/// When expected as an input type, any string (such as "4") or integer (such as 4) input value will be accepted as an ID.
pub type Id = uuid::Uuid;

#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub struct Ulid(pub UlidPrimitive);

#[Scalar]
impl ScalarType for Ulid {
    fn parse(value: Value) -> InputValueResult<Self> {
        match value {
            Value::String(s) => {
                let ulid = UlidPrimitive::from_string(&s).map_err(InputValueError::custom)?;
                Ok(Ulid(ulid))
            }
            _ => Err(InputValueError::expected_type(value)),
        }
    }

    fn to_value(&self) -> Value {
        Value::String(self.0.to_string())
    }
}

impl Type<Postgres> for Ulid {
    fn type_info() -> PgTypeInfo {
        <String as Type<Postgres>>::type_info()
    }

    fn compatible(ty: &PgTypeInfo) -> bool {
        <String as Type<Postgres>>::compatible(ty)
    }
}

impl<'r> Decode<'r, Postgres> for Ulid {
    fn decode(value: PgValueRef<'r>) -> Result<Self, Box<dyn std::error::Error + Send + Sync>> {
        let s = <String as Decode<Postgres>>::decode(value)?;

        Ok(Ulid(UlidPrimitive::from_string(s.trim())?))
    }
}

impl<'q> Encode<'q, Postgres> for Ulid {
    fn encode_by_ref(
        &self,
        buf: &mut PgArgumentBuffer,
    ) -> Result<sqlx::encode::IsNull, Box<dyn std::error::Error + Send + Sync>> {
        <String as Encode<Postgres>>::encode(self.0.to_string(), buf)
    }
}

impl PgHasArrayType for Ulid {
    fn array_type_info() -> PgTypeInfo {
        <String as PgHasArrayType>::array_type_info()
    }

    fn array_compatible(ty: &PgTypeInfo) -> bool {
        <String as PgHasArrayType>::array_compatible(ty)
    }
}