Resolve "Feat(SSE): Add msgpackr parser for SSE Client"

packages/stack/src/utils/sse-client.ts

@@ -26,9 +26,14 @@ export class SSEClient {
 
   // State.
   private url: string;
-  private options: SSEClientOptions;
   private controller: AbortController;
   private connected: boolean = false;
+  protected options: SSEClientOptions;
+  protected messageBuffer: Uint8Array = new Uint8Array();
+
+  // Text decoders and encoders for parsing the message buffer.
+  private textDecoder: TextDecoder = new TextDecoder();
+  private textEncoder: TextEncoder = new TextEncoder();
 
   /**
    * Creates a new SSEClient instance.
@@ -93,8 +98,6 @@ export class SSEClient {
           }
 
           const reader = response.body.getReader();
-          const decoder = new TextDecoder();
-          let buffer = '';
 
           // Start the read here so we can resolve and then start handling the stream
           // We will await this at the start of the loop, and redeclare it at the end of each loop iteration
@@ -115,16 +118,11 @@ export class SSEClient {
               break;
             }
 
-            // Decode the received chunk and add it to the buffer
-            const chunk = decoder.decode(value, { stream: true });
-            buffer += chunk;
-
-            // Process any complete events in the buffer
-            const events = this.parseEvents(buffer);
-            buffer = events.remainder;
+            // Decode and parse the chunk
+            const events = this.parseEvents(value);
 
             // Handle each complete event
-            for (const event of events.parsed) {
+            for (const event of events) {
               if (this.options.onMessage) {
                 this.options.onMessage(event);
               }
@@ -154,21 +152,17 @@ export class SSEClient {
     });
   }
 
-  /**
-   * Parses SSE events from a text buffer.
-   * @param buffer The buffer to parse
-   * @returns Parsed events and the remaining buffer
-   */
-  private parseEvents(buffer: string): {
-    parsed: SSEvent[];
-    remainder: string;
-  } {
+  protected parseEvents(chunk: Uint8Array): SSEvent[] {
+    // Append new chunk to existing buffer
+    this.messageBuffer = new Uint8Array([...this.messageBuffer, ...chunk]);
+
     const events: SSEvent[] = [];
-    const lines = buffer.split(/\r\n|\r|\n/);
+    const lines = this.textDecoder.decode(this.messageBuffer).split(/\r\n|\r|\n/);
 
     let currentEvent: Partial<SSEvent> = {};
     let completeEventCount = 0;
 
+    // Iterate over the lines to find complete events
     for (let i = 0; i < lines.length; i++) {
       const line = lines[i];
 
@@ -210,8 +204,11 @@ export class SSEClient {
       }
     }
 
+    // Store the remainder of the buffer for the next chunk
     const remainder = lines.slice(completeEventCount).join('\n');
-    return { parsed: events, remainder };
+    this.messageBuffer = this.textEncoder.encode(remainder);
+
+    return events;
   }
 
   /**