Fix parameter inline for tuple path params (#1014)

This commit fixes bug where already defined parameter schema were
overridden by external parameter schema in all cases. This caused an
issue where sometimes inline information was lost which caused parameter
render as reference schema instead.

Fixes #995

utoipa-gen/src/path/parameter.rs

@@ -60,7 +60,10 @@ impl<'p> Parameter<'p> {
         match (self, other) {
             (Self::Value(value), Parameter::Value(other)) => {
                 let (schema_features, _) = &value.features;
-                value.parameter_schema = other.parameter_schema;
+                // if value parameter schema has not been defined use the external one
+                if value.parameter_schema.is_none() {
+                    value.parameter_schema = other.parameter_schema;
+                }
 
                 if let Some(parameter_schema) = &mut value.parameter_schema {
                     parameter_schema.features.clone_from(schema_features);
@@ -274,7 +277,9 @@ impl Parse for ValueParameter<'_> {
 
         if input.fork().parse::<ParameterIn>().is_ok() {
             parameter.parameter_in = input.parse()?;
-            input.parse::<Token![,]>()?;
+            if !input.is_empty() {
+                input.parse::<Token![,]>()?;
+            }
         }
 
         let (schema_features, parameter_features) = input

utoipa-gen/tests/path_derive_axum_test.rs

@@ -752,3 +752,58 @@ fn derive_path_with_validation_attributes_axum() {
         config
     );
 }
+
+#[test]
+fn path_derive_inline_with_tuple() {
+    #[derive(utoipa::ToSchema)]
+    #[allow(unused)]
+    pub enum ResourceType {
+        Type1,
+        Type2,
+    }
+
+    #[utoipa::path(
+        get,
+        path = "/test_2params_separated/{resource_type}/{id}",
+        params(
+            ("resource_type" = inline(ResourceType), Path),
+            ("id" = String, Path)
+        )
+    )]
+    #[allow(unused)]
+    pub async fn inline_tuple(
+        Path((resource_type, id)): axum::extract::Path<(ResourceType, String)>,
+    ) {
+    }
+
+    use utoipa::Path;
+    let value = __path_inline_tuple::operation();
+    let value = serde_json::to_value(value).expect("operation should serialize to json");
+
+    assert_json_eq!(
+        value,
+        json!({
+            "operationId": "inline_tuple",
+            "parameters": [
+                {
+                    "in": "path",
+                    "name": "resource_type",
+                    "required": true,
+                    "schema": {
+                        "enum": ["Type1", "Type2"],
+                        "type": "string"
+                    },
+                },
+                {
+                    "in": "path",
+                    "name": "id",
+                    "required": true,
+                    "schema": {
+                        "type": "string"
+                    },
+                }
+            ],
+            "responses": {}
+        })
+    )
+}