fix: Websocket propper error when the payload size is too big

src/protocols/DisconnectionOrigin.ts

@@ -2,4 +2,5 @@ export enum DisconnectionOrigin {
   WEBSOCKET_AUTH_RENEWAL = "websocket/auth-renewal",
   USER_CONNECTION_CLOSED = "user/connection-closed",
   NETWORK_ERROR = "network/error",
+  PAYLOAD_MAX_SIZE_EXCEEDED = "payload/max-size-exceeded",
 }

src/protocols/WebSocket.ts

@@ -6,6 +6,7 @@ import { JSONObject } from "../types";
 import { RequestPayload } from "../types/RequestPayload";
 import HttpProtocol from "./Http";
 import { DisconnectionOrigin } from "./DisconnectionOrigin";
+import { parseSize } from "../utils/parseSize";
 
 /**
  * WebSocket protocol used to connect to a Kuzzle server.
@@ -15,6 +16,7 @@ export default class WebSocketProtocol extends BaseProtocolRealtime {
   private options: any;
   private client: any;
   private lasturl: any;
+  private maxPayloadSize: number;
   private ping: any;
   private waitForPong: boolean;
   private pingIntervalId: ReturnType<typeof setInterval>;
@@ -77,6 +79,7 @@ export default class WebSocketProtocol extends BaseProtocolRealtime {
       typeof options.pingInterval === "number" ? options.pingInterval : 2000;
     this.client = null;
     this.lasturl = null;
+    this.maxPayloadSize = null;
   }
 
   /**
@@ -113,11 +116,13 @@ export default class WebSocketProtocol extends BaseProtocolRealtime {
         });
       }
 
-      this.client.onopen = () => {
+      this.client.onopen = async () => {
         this.clientConnected();
 
         this.setupPingPong();
 
+        await this.getMaxPayloadSize();
+
         return resolve();
       };
 
@@ -238,6 +243,20 @@ export default class WebSocketProtocol extends BaseProtocolRealtime {
    * @param {Object} payload
    */
   send(request: RequestPayload, options: JSONObject = {}) {
+    if (
+      this.maxPayloadSize !== null &&
+      Buffer.byteLength(JSON.stringify(request), "utf8") > this.maxPayloadSize
+    ) {
+      const error: any = new Error(
+        `Payload size exceeded the maximum allowed by the server ${this.maxPayloadSize} bytes`
+      );
+
+      this.emit("networkError", { error });
+      this.clientDisconnected(DisconnectionOrigin.PAYLOAD_MAX_SIZE_EXCEEDED);
+
+      return;
+    }
+
     if (!this.client || this.client.readyState !== this.client.OPEN) {
       return;
     }
@@ -342,7 +361,7 @@ export default class WebSocketProtocol extends BaseProtocolRealtime {
       // If we were waiting for a pong that never occured before the next ping cycle we throw an error
       if (this.waitForPong) {
         const error: any = new Error(
-          "Kuzzle does'nt respond to ping. Connection lost."
+          "Kuzzle doesn't respond to ping. Connection lost."
         );
         error.status = 503;
 
@@ -359,4 +378,37 @@ export default class WebSocketProtocol extends BaseProtocolRealtime {
       }
     }, this._pingInterval);
   }
+  /**
+   * Get the maximum payload size allowed by the server
+   * Stores the value in `this.maxPayloadSize`
+   **/
+  async getMaxPayloadSize() {
+    return new Promise((resolve, reject) => {
+      const originalOnMessage = this.client.onmessage;
+      this.client.onmessage = (payload) => {
+        try {
+          const data = JSON.parse(payload.data || payload);
+
+          // Check if the message corresponds to the `getMaxPayloadSize` response
+          if (
+            data.result &&
+            data.result.server &&
+            data.result.server.maxRequestSize
+          ) {
+            this.maxPayloadSize = parseSize(data.result.server.maxRequestSize);
+
+            // Restore the original `onmessage` handler
+            this.client.onmessage = originalOnMessage;
+            resolve(this.maxPayloadSize);
+            return;
+          }
+        } catch (error) {
+          reject(error);
+        }
+      };
+
+      // Send the request
+      this.send({ action: "getConfig", controller: "server" });
+    });
+  }
 }

src/utils/parseSize.js

@@ -0,0 +1,39 @@
+function parseSize(size) {
+  const units = {
+    b: 1, // Bytes
+    kb: 1024, // Kilobytes
+    mb: 1024 * 1024, // Megabytes
+    // eslint-disable-next-line sort-keys
+    gb: 1024 * 1024 * 1024, // Gigabytes
+  };
+
+  if (typeof size !== "string") {
+    throw new Error(
+      `Invalid size input: expected a string, got ${typeof size}`
+    );
+  }
+
+  // Extract numeric value and unit
+  const match = /^(\d+(?:\.\d+)?)(b|kb|mb|gb)?$/i.exec(size.trim());
+  if (!match) {
+    throw new Error(
+      `Invalid size format: "${size}". Expected formats like "2MB", "500KB", "3GB", etc.`
+    );
+  }
+
+  const value = parseFloat(match[1]); // Get the numeric part
+  const unit = (match[2] || "b").toLowerCase(); // Default to bytes if no unit is provided
+
+  if (!units[unit]) {
+    throw new Error(
+      `Unknown size unit: "${unit}". Allowed units are B, KB, MB, GB.`
+    );
+  }
+
+  // Convert to bytes
+  return value * units[unit];
+}
+
+module.exports = {
+  parseSize,
+};