[Java] Throw useful error on incorrect argument length (#3010)

clients/java/signalr/src/main/java/com/microsoft/aspnet/signalr/JsonHubProtocol.java

@@ -3,6 +3,7 @@
 
 package com.microsoft.aspnet.signalr;
 
+import java.io.IOException;
 import java.io.StringReader;
 import java.util.ArrayList;
 import java.util.List;
@@ -12,6 +13,7 @@ import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonParser;
 import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonToken;
 
 class JsonHubProtocol implements HubProtocol {
     private final JsonParser jsonParser = new JsonParser();
@@ -77,15 +79,8 @@ class JsonHubProtocol implements HubProtocol {
                         break;
                     case "arguments":
                         if (target != null) {
-                            reader.beginArray();
                             List<Class<?>> types = binder.getParameterTypes(target);
-                            if (types != null && types.size() >= 1) {
+                            arguments = bindArguments(reader, types);
-                                arguments = new ArrayList<>();
-                                for (int i = 0; i < types.size(); i++) {
-                                    arguments.add(gson.fromJson(reader, types.get(i)));
-                                }
-                            }
-                            reader.endArray();
                         } else {
                             argumentsToken = (JsonArray)jsonParser.parse(reader);
                         }
@@ -106,12 +101,7 @@ class JsonHubProtocol implements HubProtocol {
                 case INVOCATION:
                     if (argumentsToken != null) {
                         List<Class<?>> types = binder.getParameterTypes(target);
-                        if (types != null && types.size() >= 1) {
+                        arguments = bindArguments(argumentsToken, types);
-                            arguments = new ArrayList<>();
-                            for (int i = 0; i < types.size(); i++) {
-                                arguments.add(gson.fromJson(argumentsToken.get(i), types.get(i)));
-                            }
-                        }
                     }
                     if (arguments == null) {
                         hubMessages.add(new InvocationMessage(invocationId, target, new Object[0]));
@@ -151,4 +141,42 @@ class JsonHubProtocol implements HubProtocol {
     public String writeMessage(HubMessage hubMessage) {
         return gson.toJson(hubMessage) + RECORD_SEPARATOR;
     }
+
+    private ArrayList<Object> bindArguments(JsonArray argumentsToken, List<Class<?>> paramTypes) {
+        if (argumentsToken.size() != paramTypes.size()) {
+            throw new RuntimeException(String.format("Invocation provides %d argument(s) but target expects %d.", argumentsToken.size(), paramTypes.size()));
+        }
+
+        ArrayList<Object> arguments = null;
+        if (paramTypes.size() >= 1) {
+            arguments = new ArrayList<>();
+            for (int i = 0; i < paramTypes.size(); i++) {
+                arguments.add(gson.fromJson(argumentsToken.get(i), paramTypes.get(i)));
+            }
+        }
+
+        return arguments;
+    }
+
+    private ArrayList<Object> bindArguments(JsonReader reader, List<Class<?>> paramTypes) throws IOException {
+        reader.beginArray();
+        int paramCount = paramTypes.size();
+        int argCount = 0;
+        ArrayList<Object> arguments = new ArrayList<>();
+        while (reader.peek() != JsonToken.END_ARRAY) {
+            if (argCount < paramCount) {
+                arguments.add(gson.fromJson(reader, paramTypes.get(argCount)));
+            } else {
+                reader.skipValue();
+            }
+            argCount++;
+        }
+
+        if (paramCount != argCount) {
+            throw new RuntimeException(String.format("Invocation provides %d argument(s) but target expects %d.", argCount, paramCount));
+        }
+
+        reader.endArray();
+        return arguments;
+    }
 }

clients/java/signalr/src/test/java/com/microsoft/aspnet/signalr/HubConnectionTest.java

@@ -841,7 +841,7 @@ class HubConnectionTest {
     @Test
     public void callingStartOnStartedHubConnectionNoOps() throws Exception {
         Transport mockTransport = new MockTransport();
-        HubConnection hubConnection = new HubConnection("http://example.com", mockTransport ,new NullLogger() ,true);
+        HubConnection hubConnection = new HubConnection("http://example.com", mockTransport, new NullLogger() ,true);
         hubConnection.start();
         assertEquals(HubConnectionState.CONNECTED, hubConnection.getConnectionState());
 
@@ -861,4 +861,20 @@ class HubConnectionTest {
         Throwable exception = assertThrows(HubException.class, () -> hubConnection.send("inc"));
         assertEquals("The 'send' method cannot be called if the connection is not active", exception.getMessage());
     }
+
+    @Test
+    public void errorWhenReceivingInvokeWithIncorrectArgumentLength() throws Exception {
+        MockTransport mockTransport = new MockTransport();
+        HubConnection hubConnection = new HubConnection("http://example.com", mockTransport, new NullLogger(), true);
+        hubConnection.on("Send", (s) -> {
+            assertTrue(false);
+        }, String.class);
+
+        CompletableFuture<Void> startFuture = hubConnection.start();
+        mockTransport.receiveMessage("{}" + RECORD_SEPARATOR);
+
+        startFuture.get(1000, TimeUnit.MILLISECONDS);
+        RuntimeException exception = assertThrows(RuntimeException.class, () -> mockTransport.receiveMessage("{\"type\":1,\"target\":\"Send\",\"arguments\":[]}" + RECORD_SEPARATOR));
+        assertEquals("Invocation provides 0 argument(s) but target expects 1.", exception.getMessage());
+    }
 }

clients/java/signalr/src/test/java/com/microsoft/aspnet/signalr/JsonHubProtocolTest.java

@@ -219,6 +219,33 @@ class JsonHubProtocolTest {
         assertEquals(42 , message.getResult());
     }
 
+    @Test
+    public void errorWhileParsingTooManyArgumentsWithOutOfOrderProperties() throws Exception {
+        String stringifiedMessage = "{\"arguments\":[42, 24],\"type\":1,\"target\":\"test\"}\u001E";
+        TestBinder binder = new TestBinder(new InvocationMessage(null, "test", new Object[] { 42 }));
+
+        RuntimeException exception = assertThrows(RuntimeException.class, () -> jsonHubProtocol.parseMessages(stringifiedMessage, binder));
+        assertEquals("Invocation provides 2 argument(s) but target expects 1.", exception.getMessage());
+    }
+
+    @Test
+    public void errorWhileParsingTooManyArguments() throws Exception {
+        String stringifiedMessage = "{\"type\":1,\"target\":\"test\",\"arguments\":[42, 24]}\u001E";
+        TestBinder binder = new TestBinder(new InvocationMessage(null, "test", new Object[] { 42 }));
+
+        RuntimeException exception = assertThrows(RuntimeException.class, () -> jsonHubProtocol.parseMessages(stringifiedMessage, binder));
+        assertEquals("Invocation provides 2 argument(s) but target expects 1.", exception.getMessage());
+    }
+
+    @Test
+    public void errorWhileParsingTooFewArguments() throws Exception {
+        String stringifiedMessage = "{\"type\":1,\"target\":\"test\",\"arguments\":[42]}\u001E";
+        TestBinder binder = new TestBinder(new InvocationMessage(null, "test", new Object[] { 42, 24 }));
+
+        RuntimeException exception = assertThrows(RuntimeException.class, () -> jsonHubProtocol.parseMessages(stringifiedMessage, binder));
+        assertEquals("Invocation provides 1 argument(s) but target expects 2.", exception.getMessage());
+    }
+
     private class TestBinder implements InvocationBinder {
         private Class<?>[] paramTypes = null;
         private Class<?> returnType = null;