fs: reject async iterator with ERR_STREAM_PREMATURE_CLOSE when destroy() is called during iteration

src/js/internal/fs/streams.ts

@@ -309,6 +309,16 @@
   const buf = Buffer.allocUnsafeSlow(n);
 
   this[kFs].read(this.fd, buf, 0, n, this.pos, (er, bytesRead, buf) => {
+    // If the stream was destroyed while the read was in flight, ignore the
+    // result. The fd has been (or is about to be) closed by _destroy, and
+    // pushing more data or EOF here would clobber the destroyed state —
+    // in particular, push(null) would mark the readable side as ended and
+    // suppress the ERR_STREAM_PREMATURE_CLOSE that end-of-stream/finished/
+    // async iteration relies on. Matches Node.js behavior.
+    if (this.destroyed) {
+      return;
+    }
+
     if (er) {
       require("internal/streams/destroy").errorOrDestroy(this, er);
     } else if (bytesRead > 0) {

test/js/node/fs/fs.test.ts

@@ -2221,6 +2221,26 @@ describe("createReadStream", () => {
     },
     { timeout: 100 },
   );
+
+  // https://github.com/oven-sh/bun/issues/30919
+  it("async iterator rejects with ERR_STREAM_PREMATURE_CLOSE when destroy() is called during iteration", async () => {
+    const stream = createReadStream(join(import.meta.dir, "readFileSync.txt"));
+
+    let chunks = 0;
+    let caught: any = undefined;
+    try {
+      for await (const _ of stream) {
+        chunks++;
+        stream.destroy();
+      }
+    } catch (err) {
+      caught = err;
+    }
+
+    expect(chunks).toBe(1);
+    expect(caught).toBeDefined();
+    expect(caught?.code).toBe("ERR_STREAM_PREMATURE_CLOSE");
+  });
 });
 
 describe("fs.WriteStream", () => {