The int64 scalar serializes to a string

docs/zh-CN/src/custom_scalars.md

@@ -1 +1,34 @@
 # 自定义标量
+
+`Async-graphql`已经内置了绝大部分常用的标量类型，同时你也能自定义标量。
+
+实现`Async-graphql::Scalar`即可自定义一个标量，你只需要实现一个解析函数和输出函数。
+
+下面的例子定义一个64位整数标量，但它的输入输出都是字符串。 (`Async-graphql`已经内置了对64位整数的支持，正是采用字符串作为输入输出)
+
+```rust
+use async_graphql::*;
+
+struct StringNumber(i64);
+
+impl Scalar for StringNumber {
+    fn type_name() -> &'static str {
+        // 类型名
+        "StringNumber"
+    }
+
+    fn parse(value: &Value) -> Option<Self> {
+        if let Value::String(value) = value {
+            // 解析整数
+            value.parse().ok()
+        } else {
+            // 类型不匹配则直接返回None
+            None
+        }
+    }
+}
+
+// 这个宏必须调用
+impl_scalar!(StringNumber);
+
+```

src/scalars/integers.rs

@@ -29,4 +29,36 @@ macro_rules! impl_integer_scalars {
     };
 }
 
-impl_integer_scalars!(i8, i16, i32, i64, u8, u16, u32, u64);
+impl_integer_scalars!(i8, i16, i32, u8, u16, u32);
+
+macro_rules! impl_int64_scalars {
+    ($($ty:ty),*) => {
+        $(
+        impl Scalar for $ty {
+            fn type_name() -> &'static str {
+                "Int64"
+            }
+
+            fn description() -> Option<&'static str> {
+                Some("The `Int64` scalar type represents non-fractional signed whole numeric values. Int can represent values between -(2^64) and 2^64 - 1.")
+            }
+
+            fn parse(value: &Value) -> Option<Self> {
+                match value {
+                    Value::Int(n) => Some(n.as_i64().unwrap() as Self),
+                    Value::String(s) => s.parse().ok(),
+                    _ => None
+                }
+            }
+
+            fn to_json(&self) -> Result<serde_json::Value> {
+                Ok(self.to_string().into())
+            }
+        }
+
+        impl_scalar_internal!($ty);
+        )*
+    };
+}
+
+impl_int64_scalars!(i64, u64);

tests/scalars.rs

@@ -1,7 +1,7 @@
 use async_graphql::*;
 
 macro_rules! test_scalars {
-    ($test_name:ident, $ty:ty, $value:expr) => {
+    ($test_name:ident, $ty:ty, $value:expr, $res_value:expr) => {
         #[async_std::test]
         pub async fn $test_name() {
             #[InputObject]
@@ -36,20 +36,21 @@ macro_rules! test_scalars {
             let query = format!("{{ value testArg(input: {0}) testInput(input: {{value: {0}}}) }}", json_value);
             assert_eq!(
                 schema.execute(&query).await.unwrap().data,
-                serde_json::json!({ "value": $value, "testArg": $value, "testInput": $value })
+                serde_json::json!({ "value": $res_value, "testArg": $res_value, "testInput": $res_value })
             );
         }
     };
 }
 
-test_scalars!(test_i8_scalar, i8, 10);
-test_scalars!(test_i16_scalar, i16, 10);
-test_scalars!(test_i32_scalar, i32, 10);
-test_scalars!(test_i64_scalar, i64, 10);
-test_scalars!(test_u8_scalar, u8, 10);
-test_scalars!(test_u16_scalar, u16, 10);
-test_scalars!(test_u32_scalar, u32, 10);
-test_scalars!(test_u64_scalar, u64, 10);
-test_scalars!(test_bool_scalar, bool, true);
-test_scalars!(test_f32_scalar, f32, 10.5);
-test_scalars!(test_f64_scalar, f32, 10.5);
+test_scalars!(test_i8_scalar, i8, 10, 10);
+test_scalars!(test_i16_scalar, i16, 10, 10);
+test_scalars!(test_i32_scalar, i32, 10, 10);
+test_scalars!(test_u8_scalar, u8, 10, 10);
+test_scalars!(test_u16_scalar, u16, 10, 10);
+test_scalars!(test_u32_scalar, u32, 10, 10);
+test_scalars!(test_bool_scalar, bool, true, true);
+test_scalars!(test_f32_scalar, f32, 10.5, 10.5);
+test_scalars!(test_f64_scalar, f32, 10.5, 10.5);
+
+test_scalars!(test_i64_scalar, i64, 10, "10");
+test_scalars!(test_u64_scalar, u64, 10, "10");