add disconnect monitor to firmware flash sagas

src/actions/flash-firmware.ts

@@ -50,6 +50,8 @@ type Reason<T> = {
 export enum FailToStartReasonType {
     /** Connecting to the hub failed. */
     FailedToConnect = 'flashFirmware.failToStart.reason.failedToConnect',
+    /** The hub was disconnected. */
+    Disconnected = 'flashFirmware.failToStart.reason.disconnected',
     /** The is no firmware available that matches the connected hub. */
     NoFirmware = 'flashFirmware.failToStart.reason.noFirmware',
     /** The provided firmware.zip does not match the connected hub. */
@@ -68,6 +70,8 @@ export enum FailToStartReasonType {
 
 export type FailToStartReasonFailedToConnect = Reason<FailToStartReasonType.FailedToConnect>;
 
+export type FailToStartReasonDisconnected = Reason<FailToStartReasonType.Disconnected>;
+
 export type FailToStartReasonNoFirmware = Reason<FailToStartReasonType.NoFirmware>;
 
 export type FailToStartReasonDeviceMismatch = Reason<FailToStartReasonType.DeviceMismatch>;
@@ -91,6 +95,7 @@ export type FailToStartReasonUnknown = Reason<FailToStartReasonType.Unknown> & {
 
 export type FailToStartReason =
     | FailToStartReasonFailedToConnect
+    | FailToStartReasonDisconnected
     | FailToStartReasonNoFirmware
     | FailToStartReasonDeviceMismatch
     | FailToStartReasonZipError

src/sagas/flash-firmware.test.ts

@@ -24,6 +24,7 @@ import {
     checksumResponse,
     connect,
     didConnect,
+    didDisconnect,
     didFailToConnect,
     didRequest,
     eraseRequest,
@@ -238,6 +239,64 @@ describe('flashFirmware', () => {
 
             await saga.end();
         });
+
+        test('untimely disconnect before start cancels saga', async () => {
+            const metadata: FirmwareMetadata = {
+                'metadata-version': '1.0.0',
+                'device-id': HubType.MoveHub,
+                'checksum-type': 'sum',
+                'firmware-version': '1.2.3',
+                'max-firmware-size': 1024,
+                'mpy-abi-version': 5,
+                'mpy-cross-options': ['-mno-unicode'],
+                'user-mpy-offset': 100,
+            };
+
+            const zip = new JSZip();
+            zip.file('firmware-base.bin', new Uint8Array(64));
+            zip.file('firmware.metadata.json', JSON.stringify(metadata));
+            zip.file('main.py', 'print("test")');
+            zip.file('ReadMe_OSS.txt', 'test');
+
+            jest.spyOn(window, 'fetch').mockResolvedValueOnce(
+                new Response(await zip.generateAsync({ type: 'blob' })),
+            );
+
+            const saga = new AsyncSaga(flashFirmware, {
+                nextMessageId: createCountFunc(),
+            });
+
+            saga.setState({ settings: { flashCurrentProgram: false } });
+
+            // saga is triggered by this action
+
+            saga.put(flashFirmwareAction());
+
+            // first step is to connect to the hub bootloader
+
+            let action = await saga.take();
+            expect(action).toEqual(connect());
+
+            saga.put(didConnect());
+
+            // then find out what kind of hub it is
+
+            action = await saga.take();
+            expect(action).toEqual(infoRequest(0));
+
+            saga.put(didRequest(0));
+
+            // hub disconnects before replying
+
+            saga.put(didDisconnect());
+
+            // should get a failure to start
+
+            action = await saga.take();
+            expect(action).toEqual(didFailToStart(FailToStartReasonType.Disconnected));
+
+            await saga.end();
+        });
     });
 
     describe('user supplied firmware.zip', () => {

src/sagas/flash-firmware.ts

@@ -11,6 +11,7 @@ import {
     call,
     cancel,
     delay,
+    fork,
     getContext,
     put,
     race,
@@ -19,11 +20,14 @@ import {
     takeEvery,
 } from 'typed-redux-saga/macro';
 import { Action } from '../actions';
+import { disconnect } from '../actions/ble';
 import {
+    FailToFinishReasonType,
     FailToStartReasonType,
     FlashFirmwareActionType,
     FlashFirmwareFlashAction,
     MetadataProblem,
+    didFailToFinish,
     didFailToStart,
     didFinish,
     didProgress,
@@ -201,6 +205,50 @@ function* loadFirmware(
     return { firmware, deviceId: metadata['device-id'] };
 }
 
+/**
+ * The purpose of this function is two-fold. If the BLE device is disconnected,
+ * then it will raise a failure action and cancel the task (including the
+ * parent task). Or, if the parent task fails, it will disconnect the BLE device
+ * and return.
+ */
+function* disconnectMonitor(): SagaGenerator<void> {
+    const { disconnectedBeforeStart, failedToStart } = yield* race({
+        disconnectedBeforeStart: take(BootloaderConnectionActionType.DidDisconnect),
+        started: take(FlashFirmwareActionType.DidStart),
+        failedToStart: take(FlashFirmwareActionType.DidFailToStart),
+    });
+
+    if (disconnectedBeforeStart) {
+        yield* put(didFailToStart(FailToStartReasonType.Disconnected));
+        yield* cancel();
+    }
+
+    if (failedToStart) {
+        yield* put(disconnect());
+        return;
+    }
+
+    // if we get here, `started` won the race
+
+    const { disconnectedAfterStart, failedToFinish } = yield* race({
+        disconnectedAfterStart: take(BootloaderConnectionActionType.DidDisconnect),
+        finished: take(FlashFirmwareActionType.DidFinish),
+        failedToFinish: take(FlashFirmwareActionType.DidFailToFinish),
+    });
+
+    if (disconnectedAfterStart) {
+        yield* put(didFailToFinish(FailToFinishReasonType.Disconnected));
+        yield* cancel();
+    }
+
+    if (failedToFinish) {
+        yield* put(disconnect());
+        return;
+    }
+
+    // if we get here, `finished` won the race.
+}
+
 /**
  * Flashes firmware to a Powered Up device.
  * @param action The action that triggered this saga.
@@ -242,6 +290,8 @@ function* flashFirmware(action: FlashFirmwareFlashAction): Generator {
         return;
     }
 
+    const disconnectMonitorTask = yield* fork(disconnectMonitor);
+
     const nextMessageId = yield* getContext<() => number>('nextMessageId');
 
     const infoAction = yield* put(infoRequest(nextMessageId()));
@@ -378,6 +428,7 @@ function* flashFirmware(action: FlashFirmwareFlashAction): Generator {
 
     // this will cause the remote device to disconnect and reboot
     const rebootAction = yield* put(rebootRequest(nextMessageId()));
+    disconnectMonitorTask.cancel();
     yield* waitForDidRequest(rebootAction.id);
 
     yield* put(didFinish());