Changes report: Null vendor extensions are excluded from Json/Yaml. Fixes springdoc#1525

Author: bnasslahsen

springdoc-openapi-starter-common/src/main/java/org/springdoc/core/mixins/SortedOpenAPIMixin.java

@@ -26,6 +26,8 @@
 
 import com.fasterxml.jackson.annotation.JsonAnyGetter;
 import com.fasterxml.jackson.annotation.JsonAnySetter;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonInclude.Include;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 import io.swagger.v3.core.jackson.PathsSerializer;
@@ -38,6 +40,7 @@
 public interface SortedOpenAPIMixin {
 
 	@JsonAnyGetter
+	@JsonInclude(value = Include.ALWAYS)
 	@JsonPropertyOrder(alphabetic = true)
 	Map<String, Object> getExtensions();
 

springdoc-openapi-starter-common/src/main/java/org/springdoc/core/service/OpenAPIService.java

@@ -41,6 +41,7 @@
 import java.util.stream.Stream;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import io.swagger.v3.core.jackson.TypeNameResolver;
 import io.swagger.v3.core.util.AnnotationsUtils;
 import io.swagger.v3.core.util.Json;
@@ -241,8 +242,8 @@ public void build(Locale locale) {
 		}
 		else {
 			try {
-				this.calculatedOpenAPI = Json.mapper()
-						.readValue(Json.mapper().writeValueAsString(openAPI), OpenAPI.class);
+				ObjectMapper objectMapper = new ObjectMapper();
+				this.calculatedOpenAPI = objectMapper.readValue(objectMapper.writeValueAsString(openAPI), OpenAPI.class );
 			}
 			catch (JsonProcessingException e) {
 				LOGGER.warn("Json Processing Exception occurred: {}", e.getMessage());

springdoc-openapi-starter-webmvc-api/src/test/java/test/org/springdoc/api/app138/SpringDocApp138Test.java

@@ -22,12 +22,18 @@
  */
 package test.org.springdoc.api.app138;
 
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import io.swagger.v3.oas.models.OpenAPI;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 import org.springdoc.core.utils.Constants;
 import test.org.springdoc.api.AbstractSpringDocTest;
 
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
 import org.springframework.test.context.TestPropertySource;
 import org.springframework.test.web.servlet.MvcResult;
 import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
@@ -44,8 +50,24 @@
 public class SpringDocApp138Test extends AbstractSpringDocTest {
 
 	@SpringBootApplication
-	static class SpringDocTestApp {}
+	static class SpringDocTestApp {
+		@Bean
+		public OpenAPI api() {
+			return new OpenAPI()
+					.extensions(apiExtensions());
+		}
+	}
+
+	private static Map<String, Object> apiExtensions() {
+		Map extensions = new HashMap<String, Object>();
 
+		Map linkedMap = new LinkedHashMap<String, String>();
+		linkedMap.put("property1", "value1");
+		linkedMap.put("property2", null);
+
+		extensions.put("x-my-vendor-extensions", linkedMap);
+		return extensions;
+	}
 	@Test
 	public void testApp() throws Exception {
 		MvcResult mockMvcResult = mockMvc.perform(MockMvcRequestBuilders.get(Constants.DEFAULT_API_DOCS_URL)).andExpect(status().isOk())

springdoc-openapi-starter-webmvc-api/src/test/resources/results/app138.json

@@ -1 +1 @@
-{"openapi":"3.0.1","info":{"title":"OpenAPI definition","version":"v0"},"servers":[{"url":"http://localhost","description":"Generated server url"}],"paths":{"/testA":{"get":{"tags":["hello-controller"],"operationId":"testA","parameters":[{"name":"hello","in":"query","required":true,"schema":{"type":"string"}}],"responses":{"200":{"description":"OK"}}}},"/testB":{"get":{"tags":["hello-controller"],"operationId":"testB","parameters":[{"name":"hello","in":"query","required":true,"schema":{"type":"string"}}],"responses":{"200":{"description":"OK"}}}}},"components":{}}
+{"openapi":"3.0.1","info":{"title":"OpenAPI definition","version":"v0"},"servers":[{"url":"http://localhost","description":"Generated server url"}],"paths":{"/testA":{"get":{"operationId":"testA","parameters":[{"in":"query","name":"hello","required":true,"schema":{"type":"string"}}],"responses":{"200":{"description":"OK"}},"tags":["hello-controller"]}},"/testB":{"get":{"operationId":"testB","parameters":[{"in":"query","name":"hello","required":true,"schema":{"type":"string"}}],"responses":{"200":{"description":"OK"}},"tags":["hello-controller"]}}},"components":{},"x-my-vendor-extensions":{"property1":"value1","property2":null}}