From 47231fce1020ac28965a18a213486e0125452c8f Mon Sep 17 00:00:00 2001
From: Joe Clark <jclark@openfn.org>
Date: Fri, 23 Aug 2024 10:38:43 +0100
Subject: [PATCH] mock: allow a delay on socket messages

---
 packages/lightning-mock/src/api-sockets.ts    |  4 ++-
 packages/lightning-mock/src/server.ts         |  5 ++-
 packages/lightning-mock/src/socket-server.ts  |  8 +++--
 .../lightning-mock/test/socket-server.test.ts | 36 +++++++++++++++++++
 4 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/packages/lightning-mock/src/api-sockets.ts b/packages/lightning-mock/src/api-sockets.ts
index f56d5c51d..6a4725c7d 100644
--- a/packages/lightning-mock/src/api-sockets.ts
+++ b/packages/lightning-mock/src/api-sockets.ts
@@ -83,7 +83,8 @@ const createSocketAPI = (
   path: string,
   httpServer: Server,
   logger?: Logger,
-  logLevel?: LogLevel
+  logLevel?: LogLevel,
+  socketDelay = 1
 ) => {
   // set up a websocket server to listen to connections
   const server = new WebSocketServer({
@@ -99,6 +100,7 @@ const createSocketAPI = (
     server,
     state,
     logger: logger && createLogger('PHX', { level: logLevel }),
+    socketDelay: socketDelay,
   });
 
   wss.registerEvents('worker:queue', {
diff --git a/packages/lightning-mock/src/server.ts b/packages/lightning-mock/src/server.ts
index a035d6da4..f85c34625 100644
--- a/packages/lightning-mock/src/server.ts
+++ b/packages/lightning-mock/src/server.ts
@@ -55,6 +55,8 @@ export type LightningOptions = {
 
   // if passed, a JWT will be included in all claim responses
   runPrivateKey?: string;
+
+  socketDelay?: number; // add a delay to all web socket replies
 };
 
 export type RunId = string;
@@ -107,7 +109,8 @@ const createLightningServer = (options: LightningOptions = {}) => {
     '/worker', // TODO I should option drive this
     server,
     options.logger,
-    options.logLevel
+    options.logLevel,
+    options.socketDelay
   );
 
   app.use(createDevAPI(app as any, state, logger, api));
diff --git a/packages/lightning-mock/src/socket-server.ts b/packages/lightning-mock/src/socket-server.ts
index 86df987f3..4e21de883 100644
--- a/packages/lightning-mock/src/socket-server.ts
+++ b/packages/lightning-mock/src/socket-server.ts
@@ -66,6 +66,7 @@ type CreateServerOptions = {
   state: ServerState;
   logger?: Logger;
   onMessage?: (evt: PhoenixEvent) => void;
+  socketDelay?: number;
 };
 
 type MockSocketServer = typeof WebSocketServer & {
@@ -87,6 +88,7 @@ function createServer({
   state,
   logger,
   onMessage = () => {},
+  socketDelay = 1,
 }: CreateServerOptions) {
   const channels: Record<Topic, Set<EventHandler>> = {
     // create a stub listener for pheonix to prevent errors
@@ -171,8 +173,10 @@ function createServer({
         topic,
         payload,
       });
-      // @ts-ignore
-      ws.send(evt);
+      setTimeout(() => {
+        // @ts-ignore
+        ws.send(evt);
+      }, socketDelay);
     };
 
     ws.sendJSON = async ({ event, ref, topic, payload }: PhoenixEvent) => {
diff --git a/packages/lightning-mock/test/socket-server.test.ts b/packages/lightning-mock/test/socket-server.test.ts
index c21dd6a9f..c37538c12 100644
--- a/packages/lightning-mock/test/socket-server.test.ts
+++ b/packages/lightning-mock/test/socket-server.test.ts
@@ -155,3 +155,39 @@ test.serial('onMessage', (t) => {
     });
   });
 });
+
+test.serial('defer message', (t) => {
+  return new Promise(async (done) => {
+    // Bit annoying but  we need to rebuild the server to
+    // get a delay on it
+    server.close();
+
+    server = createSocketServer({
+      // @ts-ignore
+      state: {
+        events: new EventEmitter(),
+      },
+      onMessage: (evt) => {
+        messages.push(evt);
+      },
+      socketDelay: 500,
+    });
+
+    socket = new Socket('ws://localhost:8080', {
+      transport: WebSocket,
+      params: { token: 'x.y.z' },
+    });
+
+    socket.connect();
+
+    await wait(500);
+
+    const channel = socket.channel('x', {});
+    const start = Date.now();
+    channel.join().receive('ok', async () => {
+      const duration = Date.now() - start;
+      t.assert(duration >= 500);
+      done();
+    });
+  });
+});