Add transport status events (#790)

* Transport status events

Add symbol docs
Emit transport status events
Transport test suite

* Review fixes

* Remove core dependency

* HTTP transport use AbortSignal, error handling in TransportNode

* Improve stream handling

* Update packages/transport-web-serial/src/transport.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Fix linting

---------

Co-authored-by: philon- <philon-@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

packages/transport-node/src/transport.ts

@@ -1,12 +1,25 @@
 import { Socket } from "node:net";
 import { Readable, Writable } from "node:stream";
-import type { Types } from "@meshtastic/core";
-import { Utils } from "@meshtastic/core";
+import { Types, Utils } from "@meshtastic/core";
 
+/**
+ * Node.js TCP transport for Meshtastic.
+ *
+ * Implements {@link Types.Transport} on top of a Node `net.Socket`.
+ * Use {@link TransportNode.create} to open a new connection, or
+ * construct directly with an existing socket.
+ */
 export class TransportNode implements Types.Transport {
   private readonly _toDevice: WritableStream<Uint8Array>;
   private readonly _fromDevice: ReadableStream<Types.DeviceOutput>;
+  private fromDeviceController?: ReadableStreamDefaultController<Types.DeviceOutput>;
   private socket: Socket | undefined;
+  private pipePromise?: Promise<void>;
+  private abortController: AbortController;
+  private lastStatus: Types.DeviceStatusEnum =
+    Types.DeviceStatusEnum.DeviceDisconnected;
+
+  private closingByUser = false;
 
   /**
    * Creates and connects a new TransportNode instance.
@@ -38,47 +51,131 @@ export class TransportNode implements Types.Transport {
    */
   constructor(connection: Socket) {
     this.socket = connection;
+
     this.socket.on("error", (err) => {
       console.error("Socket connection error:", err);
+      if (!this.closingByUser) {
+        this.emitStatus(
+          Types.DeviceStatusEnum.DeviceDisconnected,
+          "socket-error",
+        );
+      }
     });
 
+    this.socket.on("close", () => {
+      if (this.closingByUser) {
+        return; // suppress close-derived disconnect in user flow
+      }
+      this.emitStatus(
+        Types.DeviceStatusEnum.DeviceDisconnected,
+        "socket-closed",
+      );
+    });
+
+    this.abortController = new AbortController();
+    const abortController = this.abortController;
+
     const fromDeviceSource = Readable.toWeb(
       connection,
     ) as ReadableStream<Uint8Array>;
-    this._fromDevice = fromDeviceSource.pipeThrough(Utils.fromDeviceStream());
+    const transformed = fromDeviceSource.pipeThrough(Utils.fromDeviceStream());
+
+    this._fromDevice = new ReadableStream<Types.DeviceOutput>({
+      start: async (ctrl) => {
+        this.fromDeviceController = ctrl;
+
+        this.emitStatus(Types.DeviceStatusEnum.DeviceConnecting);
+        this.emitStatus(Types.DeviceStatusEnum.DeviceConnected);
+
+        const reader = transformed.getReader();
+        try {
+          while (true) {
+            const { value, done } = await reader.read();
+            if (done) {
+              break;
+            }
+            ctrl.enqueue(value);
+          }
+          ctrl.close();
+        } catch (error) {
+          if (this.closingByUser) {
+            ctrl.close();
+          } else {
+            this.emitStatus(
+              Types.DeviceStatusEnum.DeviceDisconnected,
+              "read-error",
+            );
+
+            ctrl.error(
+              error instanceof Error ? error : new Error(String(error)),
+            );
+          }
+          try {
+            await transformed.cancel();
+          } catch {}
+        } finally {
+          reader.releaseLock();
+        }
+      },
+    });
 
     // Stream for data going FROM the application TO the Meshtastic device.
     const toDeviceTransform = Utils.toDeviceStream;
     this._toDevice = toDeviceTransform.writable;
 
-    // The readable end of the transform is then piped to the Node.js socket.
-    // A similar assertion is needed here because `Writable.toWeb` also returns
-    // a generically typed stream (`WritableStream<any>`).
-    toDeviceTransform.readable
-      .pipeTo(Writable.toWeb(connection) as WritableStream<Uint8Array>)
+    this.pipePromise = toDeviceTransform.readable
+      .pipeTo(Writable.toWeb(connection) as WritableStream<Uint8Array>, {
+        signal: abortController.signal,
+      })
       .catch((err) => {
+        if (abortController.signal.aborted) {
+          return;
+        }
         console.error("Error piping data to socket:", err);
-        this.socket.destroy(err as Error);
+        const error = err instanceof Error ? err : new Error(String(err));
+        this.socket?.destroy(error);
       });
   }
 
-  /**
-   * The WritableStream to send data to the Meshtastic device.
-   */
+  /** WritableStream to send data to the device. */
   public get toDevice(): WritableStream<Uint8Array> {
     return this._toDevice;
   }
 
-  /**
-   * The ReadableStream to receive data from the Meshtastic device.
-   */
+  /** ReadableStream to receive data from the device. */
   public get fromDevice(): ReadableStream<Types.DeviceOutput> {
     return this._fromDevice;
   }
 
-  disconnect() {
-    this.socket.destroy();
-    this.socket = undefined;
-    return Promise.resolve();
+  /**
+   * Disconnect from the TCP socket and emit `DeviceDisconnected("user")`.
+   * Safe to call multiple times.
+   */
+  async disconnect(): Promise<void> {
+    try {
+      this.closingByUser = true;
+      this.emitStatus(Types.DeviceStatusEnum.DeviceDisconnected, "user");
+
+      this.abortController.abort();
+      if (this.pipePromise) {
+        await this.pipePromise;
+      }
+
+      this.socket?.destroy();
+    } finally {
+      this.socket = undefined;
+      this.closingByUser = false;
+    }
+  }
+
+  private emitStatus(next: Types.DeviceStatusEnum, reason?: string): void {
+    if (next === this.lastStatus) {
+      return;
+    }
+    this.lastStatus = next;
+    this.fromDeviceController?.enqueue({
+      type: "status",
+      data: { status: next, reason },
+    });
   }
 }