Abort compile if there's an RPC method with a return type (#9704)

3 files changed, 27 insertions, 4 deletions

diff --git a/client-compiler/src/com/vaadin/server/widgetsetutils/metadata/ClientRpcVisitor.java b/client-compiler/src/com/vaadin/server/widgetsetutils/metadata/ClientRpcVisitor.java
index 3b78519a0d..83aa85b482 100644
--- a/client-compiler/src/com/vaadin/server/widgetsetutils/metadata/ClientRpcVisitor.java
+++ b/client-compiler/src/com/vaadin/server/widgetsetutils/metadata/ClientRpcVisitor.java
@@ -19,6 +19,8 @@ package com.vaadin.server.widgetsetutils.metadata;
 import java.util.Set;
 
 import com.google.gwt.core.ext.TreeLogger;
+import com.google.gwt.core.ext.TreeLogger.Type;
+import com.google.gwt.core.ext.UnableToCompleteException;
 import com.google.gwt.core.ext.typeinfo.JClassType;
 import com.google.gwt.core.ext.typeinfo.JMethod;
 import com.google.gwt.core.ext.typeinfo.JType;
@@ -26,12 +28,14 @@ import com.google.gwt.core.ext.typeinfo.JType;
 public class ClientRpcVisitor extends TypeVisitor {
     @Override
     public void visitClientRpc(TreeLogger logger, JClassType type,
-            ConnectorBundle bundle) {
+            ConnectorBundle bundle) throws UnableToCompleteException {
         Set<? extends JClassType> hierarchy = type
                 .getFlattenedSupertypeHierarchy();
         for (JClassType subType : hierarchy) {
             JMethod[] methods = subType.getMethods();
             for (JMethod method : methods) {
+                checkReturnType(logger, method);
+
                 bundle.setNeedsInvoker(type, method);
                 bundle.setNeedsParamTypes(type, method);
 
@@ -42,4 +46,21 @@ public class ClientRpcVisitor extends TypeVisitor {
             }
         }
     }
+
+    public static void checkReturnType(TreeLogger logger, JMethod method)
+            throws UnableToCompleteException {
+        if (!method.getReturnType().getQualifiedSourceName().equals("void")) {
+            logger.log(
+                    Type.ERROR,
+                    "The method "
+                            + method.getEnclosingType()
+                                    .getQualifiedSourceName()
+                            + "."
+                            + method.getName()
+                            + " returns "
+                            + method.getReturnType().getQualifiedSourceName()
+                            + " but only void is supported for methods in RPC interfaces.");
+            throw new UnableToCompleteException();
+        }
+    }
 }
diff --git a/client-compiler/src/com/vaadin/server/widgetsetutils/metadata/ServerRpcVisitor.java b/client-compiler/src/com/vaadin/server/widgetsetutils/metadata/ServerRpcVisitor.java
index cbcfc3075b..fa0a8390a4 100644
--- a/client-compiler/src/com/vaadin/server/widgetsetutils/metadata/ServerRpcVisitor.java
+++ b/client-compiler/src/com/vaadin/server/widgetsetutils/metadata/ServerRpcVisitor.java
@@ -19,6 +19,7 @@ package com.vaadin.server.widgetsetutils.metadata;
 import java.util.Set;
 
 import com.google.gwt.core.ext.TreeLogger;
+import com.google.gwt.core.ext.UnableToCompleteException;
 import com.google.gwt.core.ext.typeinfo.JClassType;
 import com.google.gwt.core.ext.typeinfo.JMethod;
 import com.google.gwt.core.ext.typeinfo.JType;
@@ -26,7 +27,7 @@ import com.google.gwt.core.ext.typeinfo.JType;
 public class ServerRpcVisitor extends TypeVisitor {
     @Override
     public void visitServerRpc(TreeLogger logger, JClassType type,
-            ConnectorBundle bundle) {
+            ConnectorBundle bundle) throws UnableToCompleteException {
         bundle.setNeedsProxySupport(type);
 
         Set<? extends JClassType> superTypes = type
@@ -35,6 +36,7 @@ public class ServerRpcVisitor extends TypeVisitor {
             if (subType.isInterface() != null) {
                 JMethod[] methods = subType.getMethods();
                 for (JMethod method : methods) {
+                    ClientRpcVisitor.checkReturnType(logger, method);
                     bundle.setNeedsDelayedInfo(type, method);
 
                     JType[] parameterTypes = method.getParameterTypes();
diff --git a/client-compiler/src/com/vaadin/server/widgetsetutils/metadata/TypeVisitor.java b/client-compiler/src/com/vaadin/server/widgetsetutils/metadata/TypeVisitor.java
index 7191093755..93eed7843c 100644
--- a/client-compiler/src/com/vaadin/server/widgetsetutils/metadata/TypeVisitor.java
+++ b/client-compiler/src/com/vaadin/server/widgetsetutils/metadata/TypeVisitor.java
@@ -23,12 +23,12 @@ public abstract class TypeVisitor {
     }
 
     public void visitClientRpc(TreeLogger logger, JClassType type,
-            ConnectorBundle bundle) {
+            ConnectorBundle bundle) throws UnableToCompleteException {
         // Default does nothing
     }
 
     public void visitServerRpc(TreeLogger logger, JClassType type,
-            ConnectorBundle bundle) {
+            ConnectorBundle bundle) throws UnableToCompleteException {
         // Default does nothing
     }