From d18bbaeae42f2e6576eba4be7e89d45db5a5cf9d Mon Sep 17 00:00:00 2001
From: Mattt Zmuda <mattt@replicate.com>
Date: Wed, 7 Feb 2024 14:01:25 -0800
Subject: [PATCH] Refactor SSE construction to static method on ServerSentEvent

---
 lib/stream.js | 83 +++++++++++++++++++++++++++------------------------
 1 file changed, 44 insertions(+), 39 deletions(-)

diff --git a/lib/stream.js b/lib/stream.js
index e2e564f..9f244bf 100644
--- a/lib/stream.js
+++ b/lib/stream.js
@@ -1,4 +1,3 @@
-
 /**
  * A server-sent event.
  */
@@ -18,6 +17,39 @@ class ServerSentEvent {
     this.retry = retry;
   }
 
+  /**
+   * Parse raw event data into a ServerSentEvent instance.
+   *
+   * @param {string} rawData The raw event data.
+   * @returns {ServerSentEvent} The parsed server-sent event.
+   */
+  static parse(rawData) {
+    const lines = rawData.trim().split("\n");
+    let event = "message";
+    let data = "";
+    let id = null;
+    let retry = null;
+
+    for (const line of lines) {
+      const [fieldName, value] = line.split(/:(.*)/, 2);
+      switch (fieldName) {
+        case "event":
+          event = value.trim();
+          break;
+        case "data":
+          data += `${value.trim()}\n`;
+          break;
+        case "id":
+          id = value.trim();
+          break;
+        case "retry":
+          retry = parseInt(value.trim(), 10);
+          break;
+      }
+    }
+    return new ServerSentEvent(event, data.trim(), id, retry);
+  }
+
   /**
    * Convert the event to a string.
    */
@@ -39,35 +71,35 @@ class Stream {
         const response = await fetch(this.url, {
           ...this.options,
           headers: {
-            Accept: 'text/event-stream',
+            Accept: "text/event-stream",
           },
         });
         const reader = response.body.getReader();
         const decoder = new TextDecoder();
-        let eventBuffer = '';
+        let eventBuffer = "";
 
         const processChunk = (chunk) => {
-          eventBuffer += decoder.decode(chunk, {stream: true});
-          let eolIndex = eventBuffer.indexOf('\n');
+          eventBuffer += decoder.decode(chunk, { stream: true });
+          let eolIndex = eventBuffer.indexOf("\n");
           while (eolIndex >= 0) {
             const line = eventBuffer.slice(0, eolIndex).trim();
             eventBuffer = eventBuffer.slice(eolIndex + 1);
-            if (line === '') {
+            if (line === "") {
               // End of an event
-              const event = this.parseEvent(eventBuffer);
+              const event = ServerSentEvent.parse(eventBuffer);
               controller.enqueue(event);
-              eventBuffer = '';
+              eventBuffer = "";
             } else {
               // Accumulate data
-              eventBuffer += `${line}\n`
+              eventBuffer += `${line}\n`;
             }
 
-            eolIndex = eventBuffer.indexOf('\n');
+            eolIndex = eventBuffer.indexOf("\n");
           }
         };
 
         const push = async () => {
-          const {done, value} = await reader.read();
+          const { done, value } = await reader.read();
           if (done) {
             controller.close();
             return;
@@ -77,36 +109,9 @@ class Stream {
         };
 
         push();
-      }
+      },
     });
   }
-
-  parseEvent(rawData) {
-    const lines = rawData.trim().split('\n');
-    let event = 'message';
-    let data = '';
-    let id = null;
-    let retry = null;
-
-    for (const line of lines) {
-      const [fieldName, value] = line.split(/:(.*)/, 2);
-      switch (fieldName) {
-        case 'event':
-          event = value.trim();
-          break;
-        case 'data':
-          data += `${value.trim()}\n`;
-          break;
-        case 'id':
-          id = value.trim();
-          break;
-        case 'retry':
-          retry = parseInt(value.trim(), 10);
-          break;
-      }
-    }
-    return new ServerSentEvent(event, data.trim(), id, retry);
-  }
 }
 
 module.exports = {
-- 
2.43.0