From 0fc9a3db2f8e2c70ab2ef9b3500d7d0c18c57a95 Mon Sep 17 00:00:00 2001
From: Alex Hultman <alexhultman@gmail.com>
Date: Mon, 9 Nov 2020 14:53:41 +0100
Subject: [PATCH] Stricter arg length checks

---
 src/AppWrapper.h       | 11 +++++++----
 src/Utilities.h        | 11 +++++++++++
 src/WebSocketWrapper.h |  4 ++++
 3 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/AppWrapper.h b/src/AppWrapper.h
index 73d3154..4e2f4a0 100644
--- a/src/AppWrapper.h
+++ b/src/AppWrapper.h
@@ -24,6 +24,11 @@ using namespace v8;
 template <typename APP>
 void uWS_App_ws(const FunctionCallbackInfo<Value> &args) {
 
+    /* pattern, behavior */
+    if (missingArguments(2, args)) {
+        return;
+    }
+
     Isolate *isolate = args.GetIsolate();
 
     PerContextData *perContextData = (PerContextData *) Local<External>::Cast(args.Data())->Value();
@@ -288,9 +293,7 @@ void uWS_App_listen(const FunctionCallbackInfo<Value> &args) {
     Isolate *isolate = args.GetIsolate();
 
     /* Require at least two arguments */
-    if (args.Length() < 2) {
-        /* Throw here */
-        args.GetReturnValue().Set(isolate->ThrowException(String::NewFromUtf8(isolate, "App.listen requires port and callback", NewStringType::kNormal).ToLocalChecked()));
+    if (missingArguments(2, args)) {
         return;
     }
 
@@ -332,7 +335,7 @@ void uWS_App_publish(const FunctionCallbackInfo<Value> &args) {
     Isolate *isolate = args.GetIsolate();
 
     /* topic, message [isBinary, compress] */
-    if (args.Length() < 2) {
+    if (missingArguments(2, args)) {
         return;
     }
 
diff --git a/src/Utilities.h b/src/Utilities.h
index 7a6926b..1f0238a 100644
--- a/src/Utilities.h
+++ b/src/Utilities.h
@@ -55,6 +55,17 @@ static constexpr int getAppTypeIndex() {
     return std::is_same<APP, uWS::SSLApp>::value;
 }
 
+static inline bool missingArguments(int length, const FunctionCallbackInfo<Value> &args) {
+    if (args.Length() < length) {
+        std::string message = "Function requires at least ";
+        message += std::to_string(length);
+        message += " arguments.";
+        args.GetReturnValue().Set(args.GetIsolate()->ThrowException(String::NewFromUtf8(args.GetIsolate(), message.c_str(), NewStringType::kNormal).ToLocalChecked()));
+        return true;
+    }
+    return false;
+}
+
 struct Callback {
     bool invalid = false;
     UniquePersistent<Function> f;
diff --git a/src/WebSocketWrapper.h b/src/WebSocketWrapper.h
index 562e236..f1b3221 100644
--- a/src/WebSocketWrapper.h
+++ b/src/WebSocketWrapper.h
@@ -74,6 +74,10 @@ struct WebSocketWrapper {
         Isolate *isolate = args.GetIsolate();
         auto *ws = getWebSocket<SSL>(args);
         if (ws) {
+            if (missingArguments(2, args)) {
+                return;
+            }
+
             NativeString topic(isolate, args[0]);
             if (topic.isInvalid(args)) {
                 return;