Allow ComposedSchemas to replace non-composed so we can respect polymorphic links discovered in later methods

springdoc-openapi-common/src/main/java/org/springdoc/core/SpringDocAnnotationsUtils.java

@@ -129,9 +129,16 @@ public static Schema extractSchema(Components components, Type returnType, JsonV
 					componentSchemas.putAll(schemaMap);
 				}
 				else
-					for (Map.Entry<String, Schema> entry : schemaMap.entrySet())
-						if (!componentSchemas.containsKey(entry.getKey()))
+					for (Map.Entry<String, Schema> entry : schemaMap.entrySet()) {
+						if (!componentSchemas.containsKey(entry.getKey())) {
 							componentSchemas.put(entry.getKey(), entry.getValue());
+							// If we've seen this schema before but find later it should be polymorphic,
+							// replace the existing schema with this richer version.
+						} else if (entry.getValue() instanceof ComposedSchema &&
+							!(componentSchemas.get(entry.getKey()) instanceof ComposedSchema)) {
+							componentSchemas.put(entry.getKey(), entry.getValue());
+						}
+					}
 				components.setSchemas(componentSchemas);
 			}
 			if (resolvedSchema.schema != null) {

springdoc-openapi-data-rest/src/test/java/test/org/springdoc/api/app31/Cat.java

@@ -0,0 +1,24 @@
+package test.org.springdoc.api.app31;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@Schema
+public class Cat extends Pet {
+
+    private final boolean meows;
+
+    public Cat() {
+        super();
+        this.meows = false;
+    }
+
+    public Cat(boolean meows, String name) {
+        super(name);
+        this.meows = meows;
+    }
+
+    public boolean getMeows() {
+        return meows;
+    }
+
+}

springdoc-openapi-data-rest/src/test/java/test/org/springdoc/api/app31/Dog.java

@@ -0,0 +1,24 @@
+package test.org.springdoc.api.app31;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@Schema
+public class Dog extends Pet {
+
+    private final boolean barks;
+
+    public Dog() {
+        super();
+        this.barks = false;
+    }
+
+    public Dog(boolean barks, String name) {
+        super(name);
+        this.barks = barks;
+    }
+
+    public boolean getBarks() {
+        return barks;
+    }
+
+}

springdoc-openapi-data-rest/src/test/java/test/org/springdoc/api/app31/Pet.java

@@ -0,0 +1,23 @@
+package test.org.springdoc.api.app31;
+
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+
+@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "type")
+@JsonSubTypes({
+        @JsonSubTypes.Type(Dog.class),
+        @JsonSubTypes.Type(Cat.class)
+})
+public class Pet {
+
+    public final String name;
+
+    public Pet() {
+        this.name = null;
+    }
+
+    public Pet(String name) {
+        this.name = name;
+    }
+
+}

springdoc-openapi-data-rest/src/test/java/test/org/springdoc/api/app31/PetController.java

@@ -0,0 +1,18 @@
+package test.org.springdoc.api.app31;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class PetController {
+
+    @GetMapping("/any")
+    public Pet getAnyPet() {
+        return new Cat(true, "cat");
+    }
+
+    @GetMapping("/dog")
+    public Dog getDog() {
+        return new Dog(true, "dog");
+    }
+}

springdoc-openapi-data-rest/src/test/java/test/org/springdoc/api/app31/SpringDocApp31Test.java

@@ -0,0 +1,12 @@
+package test.org.springdoc.api.app31;
+
+import test.org.springdoc.api.AbstractSpringDocTest;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+public class SpringDocApp31Test extends AbstractSpringDocTest {
+
+    @SpringBootApplication
+    static class SpringDocTestApp {}
+
+}

springdoc-openapi-data-rest/src/test/resources/results/app31.json

@@ -0,0 +1,100 @@
+{
+  "openapi": "3.0.1",
+  "info": {
+    "title": "OpenAPI definition",
+    "version": "v0"
+  },
+  "servers": [{
+    "url": "http://localhost",
+    "description": "Generated server url"
+  }],
+  "paths": {
+    "/dog": {
+      "get": {
+        "tags": ["pet-controller"],
+        "operationId": "getDog",
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/hal+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/Dog"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/any": {
+      "get": {
+        "tags": ["pet-controller"],
+        "operationId": "getAnyPet",
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/hal+json": {
+                "schema": {
+                  "oneOf": [{
+                    "$ref": "#/components/schemas/Pet"
+                  }, {
+                    "$ref": "#/components/schemas/Cat"
+                  }, {
+                    "$ref": "#/components/schemas/Dog"
+                  }]
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  },
+  "components": {
+    "schemas": {
+      "Dog": {
+        "type": "object",
+        "allOf": [{
+          "$ref": "#/components/schemas/Pet"
+        }, {
+          "type": "object",
+          "properties": {
+            "barks": {
+              "type": "boolean"
+            }
+          }
+        }]
+      },
+      "Cat": {
+        "type": "object",
+        "allOf": [{
+          "$ref": "#/components/schemas/Pet"
+        }, {
+          "type": "object",
+          "properties": {
+            "meows": {
+              "type": "boolean"
+            }
+          }
+        }]
+      },
+      "Pet": {
+        "required": ["type"],
+        "type": "object",
+        "properties": {
+          "name": {
+            "type": "string"
+          },
+          "type": {
+            "type": "string"
+          }
+        },
+        "discriminator": {
+          "propertyName": "type"
+        }
+      }
+    }
+  }
+}