Added 'use' field to the sse client to allow passing of other fetch implementations

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

@@ -17,7 +17,7 @@ export class SSEClient {
    */
   public static async from(
     url: string,
-    options: SSEClientOptions,
+    options: Partial<SSEClientOptions> = {},
   ): Promise<SSEClient> {
     const client = new SSEClient(url, options);
     await client.connect();
@@ -35,9 +35,11 @@ export class SSEClient {
    * @param url The URL to connect to
    * @param options Configuration options
    */
-  constructor(url: string, options: SSEClientOptions) {
+  constructor(url: string, options: Partial<SSEClientOptions> = {}) {
     this.url = url;
     this.options = {
+      // Use default fetch function.
+      fetch: fetch,
       method: 'GET',
       headers: {
         Accept: 'text/event-stream',
@@ -54,14 +56,6 @@ export class SSEClient {
 
   /**
    * Connects to the SSE endpoint.
-   *
-   * @remarks
-   *
-   * This currently does not await properly and has a chance of introducing a race-condition.
-   * We want to wait for the connection to ESTABLISH before resolving.
-   * Otherwise, there is a slight possibility of missing events during the connection phase.
-   * If you try to fix this, be cautious about using a while(true) loop: JS is single threaded and you may block.
-   * Try to use the Streams event features instead.
    */
   public async connect(): Promise<void> {
     if (this.connected) return;
@@ -82,7 +76,8 @@ export class SSEClient {
       // Move the async logic inside a separate function
       const establishConnection = async () => {
         try {
-          const response = await fetch(this.url, fetchOptions);
+          // Fetch from the provided URL using our fetch function.
+          const response = await this.options.fetch(this.url, fetchOptions);
 
           if (!response.ok) {
             throw new Error(`HTTP error! Status: ${response.status}`);
@@ -242,10 +237,20 @@ export class SSEClient {
  * Configuration options for the SSEClient.
  */
 export interface SSEClientOptions {
+  /**
+   * The fetch function to use.
+   *
+   * NOTE: This is compatible with Browser/Node's native "fetcH" function.
+   *       We use this in place of "typeof fetch" so that we can accept non-standard URLs ("url" is a "string" here).
+   *       For example, a LibP2P adapter might not use a standardized URL format (and might only include "path").
+   *       This would cause a type error as native fetch expects type "URL".
+   */
+  fetch: (url: string, options: RequestInit) => Promise<Response>;
+
   /**
    * HTTP method to use (GET or POST).
    */
-  method?: 'GET' | 'POST';
+  method: 'GET' | 'POST';
 
   /**
    * HTTP headers to send with the request.