fix(core): update

ts/smartstream.functions.ts

@@ -0,0 +1,26 @@
+import { Transform, type TransformCallback, type TransformOptions } from 'stream';
+
+export interface AsyncTransformFunction<TInput, TOutput> {
+  (chunkArg: TInput): Promise<TOutput>;
+}
+
+export function createTransformFunction<TInput, TOutput>(
+  asyncFunction: AsyncTransformFunction<TInput, TOutput>,
+  options?: TransformOptions
+): Transform {
+  const transformStream = new Transform({
+    ...options,
+    objectMode: true, // Ensure we operate in object mode
+    async transform(chunk: TInput, encoding: string, callback: TransformCallback) {
+      try {
+        const transformed = await asyncFunction(chunk);
+        this.push(transformed);
+        callback();
+      } catch (error) {
+        callback(error instanceof Error ? error : new Error(String(error)));
+      }
+    }
+  });
+
+  return transformStream;
+}