From 0d57338d711bd5d81dac10d57c88afb32837aeee Mon Sep 17 00:00:00 2001
From: David Lechner <david@pybricks.com>
Date: Thu, 21 May 2020 17:33:00 -0500
Subject: [PATCH] add bootloader message serialization test

---
 src/sagas/bootloader.test.ts | 38 ++++++++++++++++++++++++++++++++++++
 src/sagas/bootloader.ts      |  3 ++-
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/src/sagas/bootloader.test.ts b/src/sagas/bootloader.test.ts
index b3210527..a0d775d1 100644
--- a/src/sagas/bootloader.test.ts
+++ b/src/sagas/bootloader.test.ts
@@ -20,6 +20,8 @@ import {
     BootloaderStateRequestAction,
     BootloaderStateResponseAction,
     didReceive,
+    didSend,
+    eraseRequest,
 } from '../actions/bootloader';
 import { Command, HubType, ProtectionLevel, Result } from '../protocols/bootloader';
 import bootloader from './bootloader';
@@ -145,6 +147,42 @@ describe('message encoder', () => {
             withResponse: false,
         });
     });
+
+    test('requests are serialized', async () => {
+        const channel = stdChannel();
+        const dispatched = new Array<Action>();
+        const task = runSaga(
+            {
+                channel,
+                dispatch: (action: Action) => dispatched.push(action),
+            },
+            bootloader,
+        );
+
+        // we send 4 requests
+        channel.put(eraseRequest());
+        channel.put(eraseRequest());
+        channel.put(eraseRequest());
+        channel.put(eraseRequest());
+
+        // but only one didSend action meaning only the first one completed
+        channel.put(didSend());
+
+        task.cancel();
+        await task.toPromise();
+
+        // so only 2 messages were actually sent and 2 are still waiting for
+        // the second one to complete
+        expect(dispatched.length).toEqual(2);
+        const message = new Uint8Array([Command.EraseFlash]);
+        for (const d of dispatched) {
+            expect(d).toEqual({
+                type: BootloaderConnectionActionType.Send,
+                data: message,
+                withResponse: false,
+            });
+        }
+    });
 });
 
 describe('message decoder', () => {
diff --git a/src/sagas/bootloader.ts b/src/sagas/bootloader.ts
index c9268eff..3d6f3c7c 100644
--- a/src/sagas/bootloader.ts
+++ b/src/sagas/bootloader.ts
@@ -114,9 +114,10 @@ function* encodeRequest(): Generator {
             case BootloaderRequestActionType.Disconnect:
                 yield put(send(createDisconnectRequest()));
                 break;
+            /* istanbul ignore next: should not be possible to reach */
             default:
                 console.error(`Unknown bootloader request action ${action}`);
-                break;
+                continue;
         }
 
         yield take(BootloaderConnectionActionType.DidSend);