Class level @tag overwrites method level @Operation.tags. Fixes #1475

Author: bnasslahsen

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

@@ -335,8 +335,17 @@ public Operation buildTags(HandlerMethod handlerMethod, Operation operation, Ope
 			}
 		}
 
-		if (!CollectionUtils.isEmpty(tagsStr))
-			operation.setTags(new ArrayList<>(tagsStr));
+		if (!CollectionUtils.isEmpty(tagsStr)) {
+			if(CollectionUtils.isEmpty(operation.getTags()))
+				operation.setTags(new ArrayList<>(tagsStr));
+			else
+			{
+				Set<String> operationTagsSet = new HashSet<>(operation.getTags());
+				operationTagsSet.addAll(tagsStr);
+				operation.getTags().clear();
+				operation.getTags().addAll(operationTagsSet);
+			}
+		}
 
 		if (isAutoTagClasses(operation))
 			operation.addTagsItem(splitCamelCase(handlerMethod.getBeanType().getSimpleName()));

springdoc-openapi-javadoc/src/test/resources/results/app1.json

@@ -334,6 +334,7 @@
     "/inventory": {
       "get": {
         "tags": [
+          "developers",
           "inventory"
         ],
         "summary": "By passing in the appropriate options, you can search for available inventory in the system ",
@@ -414,7 +415,8 @@
       },
       "post": {
         "tags": [
-          "inventory"
+          "inventory",
+          "admins"
         ],
         "summary": "Adds an item to the system",
         "description": "adds an inventory item",

springdoc-openapi-webmvc-core/src/test/resources/results/app1.json

@@ -327,6 +327,7 @@
     "/inventory": {
       "get": {
         "tags": [
+          "developers",
           "inventory"
         ],
         "summary": "By passing in the appropriate options, you can search for available inventory in the system ",
@@ -407,7 +408,8 @@
       },
       "post": {
         "tags": [
-          "inventory"
+          "inventory",
+          "admins"
         ],
         "summary": "Adds an item to the system",
         "description": "adds an inventory item",