test: add test on OneOrMany

rig-core/rig-core-derive/src/basic.rs

@@ -19,7 +19,7 @@ pub(crate) fn basic_embed_fields(data_struct: &DataStruct) -> impl Iterator<Item
     })
 }
 
-// Adds bounds to where clause that force all fields tagged with #[embed] to implement the Embeddable trait.
+/// Adds bounds to where clause that force all fields tagged with #[embed] to implement the Embeddable trait.
 pub(crate) fn add_struct_bounds(generics: &mut syn::Generics, field_type: &syn::Type) {
     let where_clause = generics.make_where_clause();
 

rig-core/rig-core-derive/src/embeddable.rs

@@ -26,7 +26,6 @@ pub(crate) fn expand_derive_embedding(input: &mut syn::DeriveInput) -> syn::Resu
                 ));
             }
 
-            // Determine whether the Embeddable::Kind should be SingleEmbedding or ManyEmbedding
             quote! {
                 let mut embed_targets = #basic_targets;
                 embed_targets.extend(#custom_targets)

rig-core/src/vec_utils.rs

@@ -188,4 +188,11 @@ mod test {
             }
         });
     }
+
+    #[test]
+    fn test_one_or_many_error() {
+        assert!(
+            OneOrMany::<String>::many(vec![]).is_err()
+        )
+    }
 }