fix: skip class introspection when $ref is derived from annotation (#2266)

* fix: skip class introspection when implementation is given in annotation

Signed-off-by: Michael Edgar <[email protected]>

* fix: skip class introspection when `$ref` is derived from annotation

Signed-off-by: Michael Edgar <[email protected]>
Co-authored-by: Andrew Rouse <[email protected]>

---------

Signed-off-by: Michael Edgar <[email protected]>
Co-authored-by: Andrew Rouse <[email protected]>

Author: MikeEdgar

core/src/main/java/io/smallrye/openapi/runtime/scanner/OpenApiDataObjectScanner.java

@@ -256,6 +256,10 @@ private void depthFirstGraphSearch() {
             TypeUtil.mapDeprecated(context, currentClass, currentSchema::getDeprecated, currentSchema::setDeprecated);
             currentPathEntry.setSchema(currentSchema);
 
+            if (currentSchema.getRef() != null) {
+                continue;
+            }
+
             if (!hasNonNullType(currentSchema)) {
                 // If not schema has yet been set, consider this an "object"
                 SchemaSupport.setType(currentSchema, Schema.SchemaType.OBJECT);
@@ -292,7 +296,7 @@ private void depthFirstGraphSearch() {
 
     private void maybeRegisterSchema(Type currentType, Schema currentSchema, Schema entrySchema) {
         Schema ref = SchemaFactory.schemaRegistration(context, currentType, currentSchema);
-
+        Schema.SchemaType type = SchemaSupport.getNonNullType(currentSchema);
         /*
          * Ignore the returned ref when:
          *
@@ -301,7 +305,7 @@ private void maybeRegisterSchema(Type currentType, Schema currentSchema, Schema
          * - the target of the ref is the schema currently being processed and using the ref would
          * result in a self-referencing schema.
          */
-        if (ref != currentSchema && !currentSchema.getType().contains(Schema.SchemaType.OBJECT) && ref.getRef() != null) {
+        if (ref != currentSchema && type != Schema.SchemaType.OBJECT && ref.getRef() != null) {
             Schema refTarget = context.getSchemaRegistry().lookupSchema(currentType, context.getJsonViews());
 
             if (refTarget != entrySchema) {

core/src/test/java/io/smallrye/openapi/runtime/scanner/StandaloneSchemaScanTest.java

@@ -1019,4 +1019,41 @@ class Response {
 
         assertJsonEquals("components.schemas.array-items-reference.json", ImmutableList.class, Greeting.class, Response.class);
     }
+
+    @Test
+    @SuppressWarnings("unused")
+    void testClassSchemaWithImplNotIntrospected() throws IOException, JSONException {
+        class UseSchemaImplementationImpl {
+            private java.math.BigDecimal amount;
+            private String currency;
+            // ... constructor and getter/setter methods ....
+        }
+
+        @Schema(implementation = UseSchemaImplementationImpl.class)
+        class UseSchemaImplementationType {
+            private String value;
+            private final String internalValue = "internalValue";
+            private final Boolean composite = true;
+
+            public final boolean isNull() {
+                return value == null;
+            }
+            // ... some other methods ...
+        }
+
+        @Schema(ref = "#/components/schemas/1UseSchemaImplementationImpl")
+        class UseSchemaImplementationType2 {
+            private String value;
+            private final String internalValue = "internalValue";
+            private final Boolean composite = true;
+
+            public final boolean isNull() {
+                return value == null;
+            }
+            // ... some other methods ...
+        }
+
+        assertJsonEquals("components.schemas.implementation-no-introspection.json", UseSchemaImplementationImpl.class,
+                UseSchemaImplementationType.class, UseSchemaImplementationType2.class);
+    }
 }

core/src/test/resources/io/smallrye/openapi/runtime/scanner/components.schemas.implementation-no-introspection.json

@@ -0,0 +1,24 @@
+{
+  "openapi" : "3.1.0",
+  "components" : {
+    "schemas" : {
+      "1UseSchemaImplementationImpl" : {
+        "type" : "object",
+        "properties" : {
+          "amount" : {
+            "type" : "number"
+          },
+          "currency" : {
+            "type" : "string"
+          }
+        }
+      },
+      "1UseSchemaImplementationType" : {
+        "$ref" : "#/components/schemas/1UseSchemaImplementationImpl"
+      },
+      "1UseSchemaImplementationType2" : {
+        "$ref" : "#/components/schemas/1UseSchemaImplementationImpl"
+      }
+    }
+  }
+}