fix test

server/src/main/java/org/elasticsearch/rest/DeprecationRestHandler.java

@@ -13,7 +13,6 @@
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.logging.DeprecationCategory;
 import org.elasticsearch.common.logging.DeprecationLogger;
-import org.elasticsearch.core.Nullable;
 
 import java.util.Objects;
 

server/src/main/java/org/elasticsearch/rest/RestController.java

@@ -145,7 +145,6 @@ public ServerlessApiProtections getApiProtections() {
         return apiProtections;
     }
 
-
     /**
      * Registers a REST handler to be executed when the provided {@code method} and {@code path} match the request.
      *
@@ -185,8 +184,8 @@ protected void registerAsDeprecatedHandler(
         } else {
             // e.g. it was marked as deprecated in 7.x, and we're currently running 9.x
             // should never happen as we only support the current and current -1 versions
-            //TODO: comment this back in when V_7 is no longer supported
-            //assert false : "Unsupported REST API version " + version;
+            // TODO: comment this back in when V_7 is no longer supported
+            // assert false : "Unsupported REST API version " + version;
         }
     }
 
@@ -223,22 +222,11 @@ protected void registerAsReplacedHandler(
         RestHandler handler,
         RestRequest.Method replacedMethod,
         String replacedPath,
-        RestApiVersion replacedVersion
+        RestApiVersion replacedVersion,
+        String replacedMessage,
+        Level deprecationLevel
     ) {
-        // e.g. [POST /_optimize] is deprecated! Use [POST /_forcemerge] instead.
-        final String replacedMessage = "["
-            + replacedMethod.name()
-            + " "
-            + replacedPath
-            + "] is deprecated! Use ["
-            + method.name()
-            + " "
-            + path
-            + "] instead.";
-
         registerHandler(method, path, version, handler);
-        //TODO: test this variant
-        Level deprecationLevel = replacedVersion == RestApiVersion.current() ? Level.WARN : DeprecationLogger.CRITICAL;
         registerAsDeprecatedHandler(replacedMethod, replacedPath, replacedVersion, handler, replacedMessage, deprecationLevel);
     }
 
@@ -283,7 +271,9 @@ public void registerHandler(final Route route, final RestHandler handler) {
                 handler,
                 replaced.getMethod(),
                 replaced.getPath(),
-                replaced.getRestApiVersion()
+                replaced.getRestApiVersion(),
+                replaced.getDeprecationMessage(),
+                replaced.getDeprecationLevel()
             );
         } else if (route.isDeprecated()) {
             registerAsDeprecatedHandler(

server/src/main/java/org/elasticsearch/rest/RestHandler.java

@@ -153,12 +153,16 @@ private Route(
         ) {
             this.method = Objects.requireNonNull(method);
             this.path = Objects.requireNonNull(path);
-            // the last version in which this route was fully supported, defaults to the current version
+            // the last version in which this route was fully supported
             this.restApiVersion = Objects.requireNonNull(restApiVersion);
 
             // a route marked as deprecated to keep or remove will have a deprecation message and level (warn for keep, critical for remove)
             this.deprecationMessage = deprecationMessage;
-            this.deprecationLevel = deprecationLevel;
+            this.deprecationLevel = Objects.requireNonNull(deprecationLevel);
+
+            if (deprecationMessage == null && deprecationLevel != Level.OFF) {
+                throw new IllegalArgumentException("deprecationMessage must be set if deprecationLevel is not OFF");
+            }
 
             // a route that replaces another route will have a reference to the route that was replaced
             this.replacedRoute = replacedRoute;
@@ -237,17 +241,38 @@ public RouteBuilder deprecatedForRemoval(String deprecationMessage, RestApiVersi
              * Route.builder(GET, "/_security/user/")
              *   .replaces(GET, "/_xpack/security/user/", RestApiVersion.V_7).build()}</pre>
              *
-             * @param method the method being replaced
-             * @param path the path being replaced
+             * @param replacedMethod the method being replaced
+             * @param replacedPath the path being replaced
              * @param lastFullySupportedVersion the last {@link RestApiVersion} (i.e. 7) for which this route is fully supported.
              *                                  The next major version (i.e. 8) will require compatibility header(s). (;compatible-with=7)
              *                                  The next major version (i.e. 9) will have no support whatsoever for this route.
              * @return a reference to this object.
              */
-            public RouteBuilder replaces(Method method, String path, RestApiVersion lastFullySupportedVersion) {
+            public RouteBuilder replaces(Method replacedMethod, String replacedPath, RestApiVersion lastFullySupportedVersion) {
                 assert this.deprecationMessage == null;
-                // the deprecation message and level will be built later
-                this.replacedRoute = new Route(method, path, lastFullySupportedVersion, null, null, null);
+
+                // if being replaced in the current version, then it's a warning, otherwise it's critical
+                Level deprecationLevel = lastFullySupportedVersion == RestApiVersion.current() ? Level.WARN : DeprecationLogger.CRITICAL;
+
+                // e.g. [POST /_optimize] is deprecated! Use [POST /_forcemerge] instead.
+                final String replacedMessage = "["
+                    + replacedMethod.name()
+                    + " "
+                    + replacedPath
+                    + "] is deprecated! Use ["
+                    + this.method.name()
+                    + " "
+                    + this.path
+                    + "] instead.";
+
+                this.replacedRoute = new Route(
+                    replacedMethod,
+                    replacedPath,
+                    lastFullySupportedVersion,
+                    replacedMessage,
+                    deprecationLevel,
+                    null
+                );
                 return this;
             }
 
@@ -281,7 +306,6 @@ public Route build() {
                     deprecationLevel == null ? Level.OFF : deprecationLevel,
                     replacedRoute
                 );
-
             }
         }
 

server/src/test/java/org/elasticsearch/rest/DeprecationRestHandlerTests.java

@@ -172,7 +172,7 @@ public void testSupportsBulkContentFalse() {
         );
     }
 
-    public void testDeprecationLevel(){
+    public void testDeprecationLevel() {
         DeprecationRestHandler handler = new DeprecationRestHandler(
             this.handler,
             METHOD,
@@ -195,26 +195,16 @@ public void testDeprecationLevel(){
         );
         assertEquals(DeprecationLogger.CRITICAL, handler.getDeprecationLevel());
 
-        IllegalArgumentException exception = expectThrows(IllegalArgumentException.class, () -> new DeprecationRestHandler(
-            this.handler,
-            METHOD,
-            PATH,
-            null,
-            deprecationMessage,
-            deprecationLogger,
-            false
-        ));
+        IllegalArgumentException exception = expectThrows(
+            IllegalArgumentException.class,
+            () -> new DeprecationRestHandler(this.handler, METHOD, PATH, null, deprecationMessage, deprecationLogger, false)
+        );
         assertEquals(exception.getMessage(), "unexpected deprecation logger level: null, expected either 'CRITICAL' or 'WARN'");
 
-        exception = expectThrows(IllegalArgumentException.class, () -> new DeprecationRestHandler(
-            this.handler,
-            METHOD,
-            PATH,
-            Level.OFF,
-            deprecationMessage,
-            deprecationLogger,
-            false
-        ));
+        exception = expectThrows(
+            IllegalArgumentException.class,
+            () -> new DeprecationRestHandler(this.handler, METHOD, PATH, Level.OFF, deprecationMessage, deprecationLogger, false)
+        );
         assertEquals(exception.getMessage(), "unexpected deprecation logger level: OFF, expected either 'CRITICAL' or 'WARN'");
     }
 

server/src/test/java/org/elasticsearch/rest/RestControllerTests.java

@@ -390,36 +390,35 @@ public void testRegisterAsReplacedHandler() {
         for (RestApiVersion replacedInVersion : replacedInVersions) {
             clearInvocations(controller);
             Route route = Route.builder(method, path).replaces(replacedMethod, replacedPath, replacedInVersion).build();
-
             // don't want to test everything -- just that it actually wraps the handler
             doCallRealMethod().when(controller).registerHandler(route, handler);
+            Level level = replacedInVersion == current ? Level.WARN : DeprecationLogger.CRITICAL;
             doCallRealMethod().when(controller)
-                .registerAsReplacedHandler(method, path, current, handler, replacedMethod, replacedPath, replacedInVersion);
-
-            controller.registerHandler(route, handler);
-
-            verify(controller).registerHandler(method, path, current, handler);
-            if (replacedInVersion.equals(current)) {
-                // is replaced in current version, which results in a critical deprecation warning
-                verify(controller).registerAsDeprecatedHandler(
-                    replacedMethod,
-                    replacedPath,
-                    replacedInVersion,
+                .registerAsReplacedHandler(
+                    method,
+                    path,
+                    current,
                     handler,
-                    deprecationMessage,
-                    Level.WARN
-                );
-            } else {
-                // is replaced in previous version, which results in a critical deprecation warning
-                verify(controller).registerAsDeprecatedHandler(
                     replacedMethod,
                     replacedPath,
                     replacedInVersion,
-                    handler,
                     deprecationMessage,
-                    DeprecationLogger.CRITICAL
+                    level
                 );
-            }
+
+            controller.registerHandler(route, handler);
+
+            // verify we registered the primary handler
+            verify(controller).registerHandler(method, path, current, handler);
+            // verify we register the replaced handler with the correct deprecation message and level
+            verify(controller).registerAsDeprecatedHandler(
+                replacedMethod,
+                replacedPath,
+                replacedInVersion,
+                handler,
+                deprecationMessage,
+                level
+            );
         }
     }