Wait for the connection before starting a file upload (#5585)

An upload started while the client was reconnecting, such as right after
returning from the Android file picker, queued its request but sent the
file frames at once. The frames were dropped and the upload failed with
"Connection changed during file upload". The upload now waits on the
same connection queue as other requests before it sends anything.

Closes #5512

Co-authored-by: paseo-bot[bot] <266920839+paseo-bot[bot]@users.noreply.github.com>

packages/client/src/daemon-client.test.ts

@@ -6906,6 +6906,70 @@ test("creation reconnect observation uses connection-owned subscriptions and rel
   expect(phases).toEqual(["accepted", "failed"]);
 });
 
+test("uploadFile started while connecting waits for the connection and uploads", async () => {
+  const mock = createMockTransport();
+  const client = new DaemonClient({
+    url: "ws://test",
+    clientId: "upload-while-connecting",
+    logger: createMockLogger(),
+    reconnect: { enabled: false },
+    suppressSendErrors: true,
+    transportFactory: () => mock.transport,
+  });
+  clients.push(client);
+  const connection = client.connect();
+  expect(client.getConnectionState().status).toBe("connecting");
+
+  const upload = client.uploadFile({
+    fileName: "notes.txt",
+    mimeType: "text/plain",
+    bytes: new TextEncoder().encode("hello world"),
+    modifiedAt: "2026-05-02T00:00:00.000Z",
+    requestId: "req-upload-connecting",
+    chunkSize: 5,
+  });
+  void upload.catch(() => undefined);
+  await new Promise((resolve) => setTimeout(resolve, 0));
+  mock.triggerOpen();
+  await connection;
+
+  await vi.waitFor(() => {
+    const frames = mock.sent
+      .filter((frame) => typeof frame !== "string")
+      .map(assertUint8Array)
+      .map(decodeFileTransferFrame);
+    expect(frames.map((frame) => frame.opcode)).toEqual([
+      FileTransferOpcode.FileBegin,
+      FileTransferOpcode.FileChunk,
+      FileTransferOpcode.FileChunk,
+      FileTransferOpcode.FileChunk,
+      FileTransferOpcode.FileEnd,
+    ]);
+  });
+  const requestIndex = mock.sent.findIndex(
+    (frame) =>
+      typeof frame === "string" && parseSentFrame(frame).requestId === "req-upload-connecting",
+  );
+  expect(parseSentFrame(mock.sent[requestIndex])).toMatchObject({ type: "file.upload.request" });
+  expect(requestIndex).toBeLessThan(mock.sent.findIndex((frame) => typeof frame !== "string"));
+
+  const file = {
+    type: "uploaded_file" as const,
+    id: "upload_req-upload-connecting",
+    fileName: "notes.txt",
+    mimeType: "text/plain",
+    size: 11,
+    path: "/tmp/paseo-uploads/upload_req-upload-connecting/notes.txt",
+  };
+  mock.triggerMessage(
+    wrapSessionMessage({
+      type: "file.upload.response",
+      payload: { requestId: "req-upload-connecting", file, error: null },
+    }),
+  );
+  await expect(upload).resolves.toEqual({ requestId: "req-upload-connecting", file, error: null });
+});
+
 test("uploadFile stops sending chunks when the connection closes between sends", async () => {
   const mock = createMockTransport();
   const client = new DaemonClient({

packages/client/src/daemon-client.ts

@@ -1169,7 +1169,7 @@ function toReasonCode(reason: string | null | undefined): string | null {
 }
 
 interface PendingSend {
-  message: SessionInboundMessage;
+  send: () => void;
   resolve: () => void;
   reject: (error: Error) => void;
   timeoutHandle: ReturnType<typeof setTimeout>;
@@ -1797,12 +1797,23 @@ export class DaemonClient {
    * This prevents waiters from hanging forever when called during connection.
    */
   private sendSessionMessageOrThrow(message: SessionInboundMessage): Promise<void> {
+    return this.sendWhenConnected(() => {
+      const payload = SessionInboundMessageSchema.parse(message);
+      this.sendJsonMessage("session", payload.type, { type: "session", message: payload });
+    });
+  }
+
+  /** Resolves once connected, waiting out a connection that is still being established. */
+  private whenConnected(): Promise<void> {
+    return this.sendWhenConnected(() => undefined);
+  }
+
+  private sendWhenConnected(send: () => void): Promise<void> {
     const status = this.connectionState.status;
 
     // If connected, send immediately
     if (this.transport && status === "connected") {
-      const payload = SessionInboundMessageSchema.parse(message);
-      this.sendJsonMessage("session", payload.type, { type: "session", message: payload });
+      send();
       return Promise.resolve();
     }
 
@@ -1823,7 +1834,7 @@ export class DaemonClient {
           );
         }, DEFAULT_SEND_QUEUE_TIMEOUT_MS);
 
-        this.pendingSendQueue.push({ message, resolve, reject, timeoutHandle });
+        this.pendingSendQueue.push({ send, resolve, reject, timeoutHandle });
       });
     }
 
@@ -1842,8 +1853,7 @@ export class DaemonClient {
       clearTimeout(pending.timeoutHandle);
       try {
         if (this.transport && this.connectionState.status === "connected") {
-          const payload = SessionInboundMessageSchema.parse(pending.message);
-          this.sendJsonMessage("session", payload.type, { type: "session", message: payload });
+          pending.send();
           pending.resolve();
         } else {
           pending.reject(new DaemonConnectionError("Connection lost before message could be sent"));
@@ -4846,6 +4856,8 @@ export class DaemonClient {
     if (!bytes) {
       throw new Error("File bytes are required.");
     }
+    // The file frames bypass the send queue, so start only on an open connection.
+    await this.whenConnected();
     const uploadTransport = this.transport;
     const resolvedRequestId = this.createRequestId(input.requestId);
     const modifiedAt = input.modifiedAt ?? new Date().toISOString();