Fix unnamed enum with tag having single field (#262)

Fix regression occurred since last release where enum with single unnamed field caused error "Unnamed (tuple) enum variants are unsupported for internally tagged enums using the `tag = ` serde attribute" but this error should only happen when enum has multiple unnamed fields.
juhaku · Aug 31, 2022 · 14157de · 14157de
1 parent 9a73ea6
commit 14157de
Show file tree

Hide file tree

Showing 2 changed files with 51 additions and 6 deletions.
diff --git a/utoipa-gen/src/component/schema.rs b/utoipa-gen/src/component/schema.rs
@@ -572,13 +572,28 @@ impl ComplexEnum<'_> {
                         .required(#tag)
                 }
             }
-            Fields::Unnamed(_) => {
-                abort!(
-                    variant,
-                    "Unnamed (tuple) enum variants are unsupported for internally tagged enums using the `tag = ` serde attribute";
+            Fields::Unnamed(unnamed_fields) => {
+                dbg!(unnamed_fields);
+                if unnamed_fields.unnamed.len() == 1 {
+                    let unnamed_enum = UnnamedStructSchema {
+                        attributes: &variant.attrs,
+                        fields: &unnamed_fields.unnamed,
+                    };
 
-                    help = "Try using a different serde enum representation";
-                );
+                    quote! {
+                        utoipa::openapi::schema::ObjectBuilder::new()
+                            #variant_title
+                            .property(#variant_name, #unnamed_enum)
+                    }
+                } else {
+                    abort!(
+                        variant,
+                        "Unnamed (tuple) enum variants are unsupported for internally tagged enums using the `tag = ` serde attribute";
+
+                        help = "Try using a different serde enum representation";
+                        note = "See more about enum limitations here: `https://serde.rs/enum-representations.html#internally-tagged`"
+                    );
+                }
             }
             Fields::Unit => {
                 let variant_tokens = Self::unit_variant_tokens(variant_name, None);

diff --git a/utoipa-gen/tests/schema_derive_test.rs b/utoipa-gen/tests/schema_derive_test.rs
@@ -736,6 +736,36 @@ fn derive_complex_unnamed_field_reference_with_comment() {
     );
 }
 
+#[test]
+fn derive_enum_with_unnamed_single_field_with_tag() {
+    #[derive(Serialize)]
+    struct ReferenceValue(String);
+
+    let value: Value = api_doc! {
+        #[derive(Serialize)]
+        #[serde(tag = "enum")]
+        enum EnumWithReference {
+            Value(ReferenceValue),
+        }
+    };
+
+    assert_json_eq!(
+        value,
+        json!({
+            "oneOf": [
+                {
+                    "type": "object",
+                    "properties": {
+                        "Value": {
+                            "$ref": "#/components/schemas/ReferenceValue",
+                        },
+                    },
+                },
+            ],
+        })
+    );
+}
+
 /// Derive a complex enum with named and unnamed fields.
 #[test]
 fn derive_complex_enum() {