From 1b990acdced52069e03b0028d336dad223a76ddf Mon Sep 17 00:00:00 2001
From: Dmitry Tantsur <dtantsur@protonmail.com>
Date: Sat, 15 Apr 2023 19:47:07 +0200
Subject: [PATCH] feat(derive): default resource_id to id when deriving
 PaginatedResource

---
 derive/src/lib.rs                  | 13 ++++++++++++-
 derive/tests/paginated_resource.rs |  8 +++-----
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/derive/src/lib.rs b/derive/src/lib.rs
index e4d3542..aada2ce 100644
--- a/derive/src/lib.rs
+++ b/derive/src/lib.rs
@@ -74,6 +74,7 @@ fn get_attr<'a>(attrs: &'a Vec<syn::Attribute>, attr: &str) -> Option<&'a syn::A
 }
 
 fn get_id_field(input: &syn::DeriveInput) -> syn::Result<(&syn::Ident, &syn::Type)> {
+    let mut default_id = None;
     if let syn::Data::Struct(ref st) = input.data {
         if let syn::Fields::Named(ref fs) = st.fields {
             for field in &fs.named {
@@ -83,6 +84,12 @@ fn get_id_field(input: &syn::DeriveInput) -> syn::Result<(&syn::Ident, &syn::Typ
                         &field.ty,
                     ));
                 }
+
+                if let Some(id) = field.ident.as_ref() {
+                    if id == "id" {
+                        default_id = Some((id, &field.ty));
+                    }
+                }
             }
         } else {
             return Err(syn::Error::new_spanned(
@@ -97,7 +104,11 @@ fn get_id_field(input: &syn::DeriveInput) -> syn::Result<(&syn::Ident, &syn::Typ
         ));
     }
 
-    Err(syn::Error::new_spanned(input, "#[resource_id] missing"))
+    if let Some(id) = default_id {
+        Ok(id)
+    } else {
+        Err(syn::Error::new_spanned(input, "#[resource_id] missing"))
+    }
 }
 
 fn get_collection_name(input: &syn::DeriveInput) -> syn::Result<Option<String>> {
diff --git a/derive/tests/paginated_resource.rs b/derive/tests/paginated_resource.rs
index 4b9b95b..4a4ade3 100644
--- a/derive/tests/paginated_resource.rs
+++ b/derive/tests/paginated_resource.rs
@@ -4,7 +4,6 @@ use osauth_derive::PaginatedResource;
 
 #[derive(Debug, Deserialize, PaginatedResource)]
 struct SimpleResource {
-    #[resource_id]
     pub id: String,
     #[allow(dead_code)]
     pub not_id: String,
@@ -14,13 +13,12 @@ struct SimpleResource {
 #[collection_name = "items"]
 struct RenamedResource {
     #[resource_id]
-    pub id: String,
+    pub uuid: String,
 }
 
 #[derive(Debug, Deserialize, PaginatedResource)]
 #[flat_collection]
 struct FlatResource {
-    #[resource_id]
     pub id: String,
 }
 
@@ -48,13 +46,13 @@ fn test_renamed_collection() {
     use osauth::PaginatedResource;
 
     let res = RenamedResource {
-        id: "the id".into(),
+        uuid: "the id".into(),
     };
 
     let res_id: String = res.resource_id();
     assert_eq!(&res_id, "the id");
 
-    let json = r#"{"items": [{"id": "1"}, {"id": "2"}]}"#;
+    let json = r#"{"items": [{"uuid": "1"}, {"uuid": "2"}]}"#;
     let resources: <RenamedResource as PaginatedResource>::Root =
         serde_json::from_str(json).unwrap();
     assert_eq!(resources.items.len(), 2);