fix(debug-ios): clean up and exit when the app's socket closes

The backend close handler cleared the session before closing the WebSocket, so the WebSocket's close handler no longer saw it as current and skipped destroying the socket and exiting without --watch.

Author: rigor789

lib/common/test/unit-tests/services/net-service.ts

@@ -30,14 +30,18 @@ describe("net", () => {
 		const hosts = [undefined, "127.0.0.1", "::1", "0.0.0.0", "::"];
 
 		for (const host of hosts) {
-			it(`returns false for a port taken on ${host || "the default address"}`, async () => {
+			it(`returns false for a port taken on ${host || "the default address"}`, async function () {
 				const service = createTestInjector("darwin").resolve<INet>(Net);
 				const server = net.createServer();
-				await new Promise<void>((resolve) =>
-					host
-						? server.listen(0, host, () => resolve())
-						: server.listen(0, () => resolve()),
-				);
+				const listening = await new Promise<boolean>((resolve) => {
+					server.once("error", () => resolve(false));
+					const onListening = () => resolve(true);
+					host ? server.listen(0, host, onListening) : server.listen(0, onListening);
+				});
+				if (!listening) {
+					this.skip();
+					return;
+				}
 				const { port } = <net.AddressInfo>server.address();
 
 				try {

lib/device-sockets/ios/app-debug-socket-proxy-factory.ts

@@ -290,9 +290,6 @@ export class AppDebugSocketProxyFactory
 
 			appDebugSocket.on("close", () => {
 				this.$logger.trace("Backend socket closed!");
-				if (currentSession === session) {
-					currentSession = null;
-				}
 				webSocket.close();
 			});
 

test/device-sockets/app-debug-socket-proxy-factory.ts

@@ -1,6 +1,7 @@
 import { assert } from "chai";
 import * as net from "net";
 import * as os from "os";
+import * as sinon from "sinon";
 import * as ws from "ws";
 import { MessageUnpackStream } from "ios-device-lib";
 import {
@@ -18,6 +19,11 @@ const encode = (message: string): Buffer => {
 	return payload;
 };
 
+const hasIPv6Loopback = () =>
+	Object.values(os.networkInterfaces())
+		.flat()
+		.some((address) => address.internal && address.family === "IPv6");
+
 describe("AppDebugSocketProxyFactory", () => {
 	let backend: net.Server;
 	let backendPort: number;
@@ -61,11 +67,14 @@ describe("AppDebugSocketProxyFactory", () => {
 		};
 	};
 
-	const createProxy = (getAvailablePortInRange?: () => Promise<number>) =>
+	const createProxy = (
+		getAvailablePortInRange?: () => Promise<number>,
+		watch = true,
+	) =>
 		new AppDebugSocketProxyFactory(
 			<any>{ info: () => {}, trace: () => {}, warn: () => {} },
 			<any>{ fail: (message: string) => assert.fail(message) },
-			<any>{ watch: true },
+			<any>{ watch },
 			<any>{},
 			<any>{
 				getAvailablePortInRange:
@@ -161,7 +170,11 @@ describe("AppDebugSocketProxyFactory", () => {
 	it("listens on both loopback addresses and nothing else", async () => {
 		const port = await startProxy();
 
-		for (const host of ["127.0.0.1", "[::1]"]) {
+		const hosts = ["127.0.0.1"];
+		if (hasIPv6Loopback()) {
+			hosts.push("[::1]");
+		}
+		for (const host of hosts) {
 			const client = await open(port, undefined, host);
 			assert.equal(await roundTrip(client, host), host);
 		}
@@ -229,6 +242,27 @@ describe("AppDebugSocketProxyFactory", () => {
 		assert.equal(backendConnections, 2);
 	});
 
+	it("cleans up and exits without watch when the app goes away", async () => {
+		const exit = sinon.stub(process, "exit");
+		const destroyDebugSocket = sinon.spy(device, "destroyDebugSocket");
+		try {
+			const port = await startProxy(createProxy(undefined, false));
+			const client = await open(port);
+			const closed = closeReason(client);
+			const appSocket = await device.getDebugSocket("app");
+
+			appSocket.destroy();
+			await closed;
+			await new Promise((resolve) => setTimeout(resolve, 20));
+
+			assert.isTrue(destroyDebugSocket.called);
+			assert.isTrue(exit.calledWith(0));
+		} finally {
+			exit.restore();
+			destroyDebugSocket.restore();
+		}
+	});
+
 	it("keeps the new client's backend when the replaced client closes late", async () => {
 		const port = await startProxy();
 		const first = await open(port);