add ID scalar

README.md

@@ -34,6 +34,7 @@
         - [X] Float
         - [X] String
         - [X] Bool
+        - [X] ID
         - [X] DateTime
         - [X] UUID
     - Complex Types

src/datetime.rs

@@ -1,5 +1,4 @@
 use crate::{QueryError, Result, Scalar, Value};
-use anyhow::Error;
 use chrono::{DateTime, TimeZone, Utc};
 
 impl Scalar for DateTime<Utc> {

src/id.rs

@@ -0,0 +1,57 @@
+use crate::{QueryError, Result, Scalar, Value};
+use std::ops::{Deref, DerefMut};
+
+#[derive(Clone, Ord, PartialOrd, Eq, PartialEq, Hash, Debug)]
+pub struct ID(String);
+
+impl Deref for ID {
+    type Target = String;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for ID {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+impl Scalar for ID {
+    fn type_name() -> &'static str {
+        "ID"
+    }
+
+    fn parse(value: Value) -> Result<Self> {
+        match value {
+            Value::Int(n) => Ok(ID(n.as_i64().unwrap().to_string())),
+            Value::String(s) => Ok(ID(s)),
+            _ => {
+                return Err(QueryError::ExpectedType {
+                    expect: Self::type_name().to_string(),
+                    actual: value,
+                }
+                .into())
+            }
+        }
+    }
+
+    fn parse_from_json(value: serde_json::Value) -> Result<Self> {
+        match value {
+            serde_json::Value::Number(n) if n.is_i64() => Ok(ID(n.as_i64().unwrap().to_string())),
+            serde_json::Value::String(s) => Ok(ID(s)),
+            _ => {
+                return Err(QueryError::ExpectedJsonType {
+                    expect: Self::type_name().to_string(),
+                    actual: value,
+                }
+                .into())
+            }
+        }
+    }
+
+    fn into_json(self) -> Result<serde_json::Value> {
+        Ok(self.0.clone().into())
+    }
+}

src/lib.rs

@@ -36,6 +36,7 @@ extern crate thiserror;
 mod context;
 mod r#enum;
 mod error;
+mod id;
 mod query;
 mod scalar;
 mod r#type;
@@ -54,6 +55,7 @@ pub use async_graphql_derive::{Enum, InputObject, Object};
 pub use context::{Context, ContextField, ContextSelectionSet, Data, Variables};
 pub use error::{ErrorWithPosition, PositionError, QueryError, QueryParseError};
 pub use graphql_parser::query::Value;
+pub use id::ID;
 pub use query::QueryBuilder;
 pub use scalar::Scalar;
 

src/scalar.rs

@@ -1,6 +1,5 @@
 use crate::r#type::{GQLInputValue, GQLOutputValue, GQLType};
 use crate::{ContextSelectionSet, QueryError, Result};
-use anyhow::Error;
 use graphql_parser::query::Value;
 
 pub trait Scalar: Sized + Send {

src/type.rs

@@ -1,5 +1,4 @@
 use crate::{ContextSelectionSet, ErrorWithPosition, QueryError, Result};
-use anyhow::Error;
 use graphql_parser::query::Value;
 
 #[doc(hidden)]

src/uuid.rs

@@ -1,5 +1,4 @@
 use crate::{QueryError, Result, Scalar, Value};
-use anyhow::Error;
 use uuid::Uuid;
 
 impl Scalar for Uuid {