fix(core): Improve streaming support and timeout handling; add browser streaming & timeout tests and README clarifications

ts/core_fetch/request.ts

@@ -9,6 +9,9 @@ export class CoreRequest extends AbstractCoreRequest<
   types.ICoreRequestOptions,
   CoreResponse
 > {
+  private timeoutId: ReturnType<typeof setTimeout> | null = null;
+  private abortController: AbortController | null = null;
+
   constructor(url: string, options: types.ICoreRequestOptions = {}) {
     super(url, options);
 
@@ -61,11 +64,19 @@ export class CoreRequest extends AbstractCoreRequest<
       if (
         typeof this.options.requestBody === 'string' ||
         this.options.requestBody instanceof ArrayBuffer ||
+        this.options.requestBody instanceof Uint8Array ||
         this.options.requestBody instanceof FormData ||
         this.options.requestBody instanceof URLSearchParams ||
-        this.options.requestBody instanceof ReadableStream
+        this.options.requestBody instanceof ReadableStream ||
+        // Check for Buffer (Node.js polyfills in browser may provide this)
+        (typeof Buffer !== 'undefined' && this.options.requestBody instanceof Buffer)
       ) {
         fetchOptions.body = this.options.requestBody;
+        
+        // If streaming, we need to set duplex mode
+        if (this.options.requestBody instanceof ReadableStream) {
+          (fetchOptions as any).duplex = 'half';
+        }
       } else {
         // Convert objects to JSON
         fetchOptions.body = JSON.stringify(this.options.requestBody);
@@ -92,9 +103,13 @@ export class CoreRequest extends AbstractCoreRequest<
     if (this.options.timeout || this.options.hardDataCuttingTimeout) {
       const timeout =
         this.options.hardDataCuttingTimeout || this.options.timeout;
-      const controller = new AbortController();
-      setTimeout(() => controller.abort(), timeout);
-      fetchOptions.signal = controller.signal;
+      this.abortController = new AbortController();
+      this.timeoutId = setTimeout(() => {
+        if (this.abortController) {
+          this.abortController.abort();
+        }
+      }, timeout);
+      fetchOptions.signal = this.abortController.signal;
     }
 
     return fetchOptions;
@@ -117,8 +132,12 @@ export class CoreRequest extends AbstractCoreRequest<
 
     try {
       const response = await fetch(url, options);
+      // Clear timeout on successful response
+      this.clearTimeout();
       return response;
     } catch (error) {
+      // Clear timeout on error
+      this.clearTimeout();
       if (error.name === 'AbortError') {
         throw new Error('Request timed out');
       }
@@ -126,6 +145,19 @@ export class CoreRequest extends AbstractCoreRequest<
     }
   }
 
+  /**
+   * Clear the timeout and abort controller
+   */
+  private clearTimeout(): void {
+    if (this.timeoutId) {
+      clearTimeout(this.timeoutId);
+      this.timeoutId = null;
+    }
+    if (this.abortController) {
+      this.abortController = null;
+    }
+  }
+
   /**
    * Static factory method to create and fire a request
    */