codegen: enable ids to be deserialized from strings or integers

graphql_client/src/lib.rs

@@ -30,6 +30,8 @@ pub use graphql_query_derive::*;
 ))]
 pub mod reqwest;
 
+pub mod serde_with;
+
 use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
 use std::fmt::{self, Display, Write};

graphql_client/src/serde_with.rs

@@ -0,0 +1,27 @@
+//! Helpers for overriding default serde implementations.
+
+use serde::{Deserialize, Deserializer};
+
+/// Deserialize an optional ID type from either a String or an Integer representation.
+///
+/// This is used by the codegen to enable String IDs to be deserialized from
+/// either Strings or Integers.
+pub fn deserialize_option_id<'de, D>(deserializer: D) -> Result<Option<String>, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    #[derive(Deserialize)]
+    #[serde(untagged)]
+    enum IntOrString {
+        Int(i64),
+        Str(String),
+    }
+
+    let res = Option::<IntOrString>::deserialize(deserializer)?;
+
+    Ok(match res {
+        None => None,
+        Some(IntOrString::Int(n)) => Some(n.to_string()),
+        Some(IntOrString::Str(s)) => Some(s),
+    })
+}

graphql_client/tests/int_id.rs

@@ -0,0 +1,41 @@
+use graphql_client::*;
+use serde_json::json;
+
+#[derive(GraphQLQuery)]
+#[graphql(
+    schema_path = "tests/more_derives/schema.graphql",
+    query_path = "tests/more_derives/query.graphql",
+    response_derives = "Debug, PartialEq, Eq, std::cmp::PartialOrd"
+)]
+pub struct MoreDerives;
+
+#[test]
+fn int_id() {
+    let response1 = json!({
+        "currentUser": {
+            "id": 1,
+            "name": "Don Draper",
+        }
+    });
+
+    let response2 = json!({
+        "currentUser": {
+            "id": "2",
+            "name": "Peggy Olson",
+        }
+    });
+
+    let res1 = serde_json::from_value::<more_derives::ResponseData>(response1)
+        .expect("should deserialize");
+    assert_eq!(
+        res1.current_user.expect("res1 current user").id,
+        Some("1".into())
+    );
+
+    let res2 = serde_json::from_value::<more_derives::ResponseData>(response2)
+        .expect("should deserialize");
+    assert_eq!(
+        res2.current_user.expect("res2 current user").id,
+        Some("2".into())
+    );
+}

graphql_client/tests/int_id/query.graphql

@@ -0,0 +1,6 @@
+query MoreDerives {
+  currentUser {
+    name
+    id
+  }
+}

graphql_client/tests/int_id/schema.graphql

@@ -0,0 +1,12 @@
+schema {
+  query: TestQuery
+}
+
+type TestQuery {
+  currentUser: TestUser
+}
+
+type TestUser {
+  name: String
+  id: ID
+}

graphql_client_codegen/src/codegen/selection.rs

@@ -405,6 +405,14 @@ impl<'a> ExpandedField<'a> {
             qualified_type
         };
 
+        let id_deserialize_with = if self.field_type == "ID" {
+            Some(
+                quote!(#[serde(deserialize_with = "graphql_client::serde_with::deserialize_option_id")]),
+            )
+        } else {
+            None
+        };
+
         let optional_skip_serializing_none = if *options.skip_serializing_none()
             && self
                 .field_type_qualifiers
@@ -443,6 +451,7 @@ impl<'a> ExpandedField<'a> {
             #optional_flatten
             #optional_rename
             #optional_deprecation_annotation
+            #id_deserialize_with
             pub #ident: #qualified_type
         };