Handle disconnects (#363)

* Make proxies decide how to handle disconnects

* Connect to a new terminal instance on disconnect

* Use our retry for the watcher

* Specify method when proxy doesn't exist

* Don't error when closing/killing disconnected proxy

* Specify proxy ID when a method doesn't exist

* Use our retry for the searcher

Also dispose some things for the watcher because it doesn't seem that
was done properly.

The searcher also now starts immediately so there won't be lag when you
perform your first search.

* Use our retry for the extension host

* Emit error in parent proxy class

Reduces duplicate code. Not all items are "supposed" to have an error
event according to the original implementation we are filling, but there
is no reason why we can't emit our own events (and are already doing so
for the "disconnected" event anyway).

* Reconnect spdlog

* Add error message when shared process disconnects

* Pass method resolve to parse

* Don't pass method to getProxy

It doesn't tell you anything that trace logging wouldn't and has
no relation to what the function actually does.

* Fix infinite recursion when disposing protocol client in tests

packages/protocol/src/browser/client.ts

@@ -134,14 +134,8 @@ export class Client {
 			message.setResponse(stringify(error));
 			this.failEmitter.emit(message);
 
-			this.eventEmitter.emit({ event: "exit", args: [1] });
-			this.eventEmitter.emit({ event: "close", args: [] });
-			try {
-				this.eventEmitter.emit({ event: "error", args: [error] });
-			} catch (error) {
-				// If nothing is listening, EventEmitter will throw an error.
-			}
-			this.eventEmitter.emit({ event: "done", args: [true] });
+			this.eventEmitter.emit({ event: "disconnected", args: [error] });
+			this.eventEmitter.emit({ event: "done", args: [] });
 		};
 
 		connection.onDown(() => handleDisconnect());
@@ -149,6 +143,12 @@ export class Client {
 			clearTimeout(this.pingTimeout as any);
 			this.pingTimeout = undefined;
 			handleDisconnect();
+			this.proxies.clear();
+			this.successEmitter.dispose();
+			this.failEmitter.dispose();
+			this.eventEmitter.dispose();
+			this.initDataEmitter.dispose();
+			this.sharedProcessActiveEmitter.dispose();
 		});
 		connection.onUp(() => this.disconnected = false);
 
@@ -174,8 +174,17 @@ export class Client {
 	 * Make a remote call for a proxy's method using proto.
 	 */
 	private remoteCall(proxyId: number | Module, method: string, args: any[]): Promise<any> {
-		if (this.disconnected) {
-			return Promise.reject(new Error("disconnected"));
+		if (this.disconnected && typeof proxyId === "number") {
+			// Can assume killing or closing works because a disconnected proxy
+			// is disposed on the server's side.
+			switch (method) {
+				case "close":
+				case "kill":
+					return Promise.resolve();
+			}
+			return Promise.reject(
+				new Error(`Unable to call "${method}" on proxy ${proxyId}: disconnected`),
+			);
 		}
 
 		const message = new MethodMessage();
@@ -223,7 +232,7 @@ export class Client {
 
 		// The server will send back a fail or success message when the method
 		// has completed, so we listen for that based on the message's unique ID.
-		const promise =  new Promise((resolve, reject): void => {
+		const promise = new Promise((resolve, reject): void => {
 			const dispose = (): void => {
 				d1.dispose();
 				d2.dispose();
@@ -237,7 +246,7 @@ export class Client {
 
 			const d1 = this.successEmitter.event(id, (message) => {
 				dispose();
-				resolve(this.parse(message.getResponse()));
+				resolve(this.parse(message.getResponse(), promise));
 			});
 
 			const d2 = this.failEmitter.event(id, (message) => {
@@ -450,12 +459,12 @@ export class Client {
 			callbacks: new Map(),
 		});
 
-		instance.onDone((disconnected: boolean) => {
+		instance.onDone(() => {
 			const log = (): void => {
 				logger.trace(() => [
 					typeof proxyId === "number" ? "disposed proxy" : "disposed proxy callbacks",
 					field("proxyId", proxyId),
-					field("disconnected", disconnected),
+					field("disconnected", this.disconnected),
 					field("callbacks", Array.from(this.proxies.values()).reduce((count, proxy) => count + proxy.callbacks.size, 0)),
 					field("success listeners", this.successEmitter.counts),
 					field("fail listeners", this.failEmitter.counts),
@@ -471,7 +480,7 @@ export class Client {
 					this.eventEmitter.dispose(proxyId);
 					log();
 				};
-				if (!disconnected) {
+				if (!this.disconnected) {
 					instance.dispose().then(dispose).catch(dispose);
 				} else {
 					dispose();

packages/protocol/src/browser/modules/child_process.ts

@@ -87,6 +87,11 @@ export class ChildProcess extends ClientProxy<ChildProcessProxy> implements cp.C
 
 		return true; // Always true since we can't get this synchronously.
 	}
+
+	protected handleDisconnect(): void {
+		this.emit("exit", 1);
+		this.emit("close");
+	}
 }
 
 export class ChildProcessModule {

packages/protocol/src/browser/modules/fs.ts

@@ -41,6 +41,10 @@ class Watcher extends ClientProxy<WatcherProxy> implements fs.FSWatcher {
 	public close(): void {
 		this.proxy.close();
 	}
+
+	protected handleDisconnect(): void {
+		this.emit("close");
+	}
 }
 
 class WriteStream extends Writable<WriteStreamProxy> implements fs.WriteStream {

packages/protocol/src/browser/modules/net.ts

@@ -126,6 +126,7 @@ export class Socket extends Duplex<NetSocketProxy> implements net.Socket {
 }
 
 export class Server extends ClientProxy<NetServerProxy> implements net.Server {
+	private socketId = 0;
 	private readonly sockets = new Map<number, net.Socket>();
 	private _listening: boolean = false;
 
@@ -133,7 +134,12 @@ export class Server extends ClientProxy<NetServerProxy> implements net.Server {
 		super(proxyPromise);
 
 		this.proxy.onConnection((socketProxy) => {
-			this.emit("connection", new Socket(socketProxy));
+			const socket = new Socket(socketProxy);
+			const socketId = this.socketId++;
+			this.sockets.set(socketId, socket);
+			socket.on("error", () => this.sockets.delete(socketId))
+			socket.on("close", () => this.sockets.delete(socketId))
+			this.emit("connection", socket);
 		});
 
 		this.on("listening", () => this._listening = true);
@@ -200,6 +206,10 @@ export class Server extends ClientProxy<NetServerProxy> implements net.Server {
 	public getConnections(cb: (error: Error | null, count: number) => void): void {
 		cb(null, this.sockets.size);
 	}
+
+	protected handleDisconnect(): void {
+		this.emit("close");
+	}
 }
 
 type NodeNet = typeof net;

packages/protocol/src/browser/modules/node-pty.ts

@@ -6,11 +6,20 @@ export class NodePtyProcess extends ClientProxy<NodePtyProcessProxy> implements
 	private _pid = -1;
 	private _process = "";
 
-	public constructor(proxyPromise: Promise<NodePtyProcessProxy>) {
-		super(proxyPromise);
+	public constructor(
+		private readonly moduleProxy: NodePtyModuleProxy,
+		private readonly file: string,
+		private readonly args: string[] | string,
+		private readonly options: pty.IPtyForkOptions,
+	) {
+		super(moduleProxy.spawn(file, args, options));
+		this.on("process", (process) => this._process = process);
+	}
+
+	protected initialize(proxyPromise: Promise<NodePtyProcessProxy>) {
+		super.initialize(proxyPromise);
 		this.proxy.getPid().then((pid) => this._pid = pid);
 		this.proxy.getProcess().then((process) => this._process = process);
-		this.on("process", (process) => this._process = process);
 	}
 
 	public get pid(): number {
@@ -32,6 +41,12 @@ export class NodePtyProcess extends ClientProxy<NodePtyProcessProxy> implements
 	public kill(signal?: string): void {
 		this.proxy.kill(signal);
 	}
+
+	protected handleDisconnect(): void {
+		this._process += " (disconnected)";
+		this.emit("data", "\r\n\nLost connection...\r\n\n");
+		this.initialize(this.moduleProxy.spawn(this.file, this.args, this.options));
+	}
 }
 
 type NodePty = typeof pty;
@@ -40,6 +55,6 @@ export class NodePtyModule implements NodePty {
 	public constructor(private readonly proxy: NodePtyModuleProxy) {}
 
 	public spawn = (file: string, args: string[] | string, options: pty.IPtyForkOptions): pty.IPty => {
-		return new NodePtyProcess(this.proxy.spawn(file, args, options));
+		return new NodePtyProcess(this.proxy, file, args, options);
 	}
 }

packages/protocol/src/browser/modules/spdlog.ts

@@ -3,6 +3,16 @@ import { ClientProxy } from "../../common/proxy";
 import { RotatingLoggerProxy, SpdlogModuleProxy } from "../../node/modules/spdlog";
 
 class RotatingLogger extends ClientProxy<RotatingLoggerProxy> implements spdlog.RotatingLogger {
+	public constructor(
+		private readonly moduleProxy: SpdlogModuleProxy,
+		private readonly name: string,
+		private readonly filename: string,
+		private readonly filesize: number,
+		private readonly filecount: number,
+	) {
+		super(moduleProxy.createLogger(name, filename, filesize, filecount));
+	}
+
 	public async trace (message: string): Promise<void> { this.proxy.trace(message); }
 	public async debug (message: string): Promise<void> { this.proxy.debug(message); }
 	public async info (message: string): Promise<void> { this.proxy.info(message); }
@@ -13,6 +23,10 @@ class RotatingLogger extends ClientProxy<RotatingLoggerProxy> implements spdlog.
 	public async clearFormatters (): Promise<void> { this.proxy.clearFormatters(); }
 	public async flush (): Promise<void> { this.proxy.flush(); }
 	public async drop (): Promise<void> { this.proxy.drop(); }
+
+	protected handleDisconnect(): void {
+		this.initialize(this.moduleProxy.createLogger(this.name, this.filename, this.filesize, this.filecount));
+	}
 }
 
 export class SpdlogModule {
@@ -21,7 +35,7 @@ export class SpdlogModule {
 	public constructor(private readonly proxy: SpdlogModuleProxy) {
 		this.RotatingLogger = class extends RotatingLogger {
 			public constructor(name: string, filename: string, filesize: number, filecount: number) {
-				super(proxy.createLogger(name, filename, filesize, filecount));
+				super(proxy, name, filename, filesize, filecount);
 			}
 		};
 	}

packages/protocol/src/browser/modules/stream.ts

@@ -81,6 +81,11 @@ export class Writable<T extends WritableProxy = WritableProxy> extends ClientPro
 			}
 		});
 	}
+
+	protected handleDisconnect(): void {
+		this.emit("close");
+		this.emit("finish");
+	}
 }
 
 export class Readable<T extends IReadableProxy = IReadableProxy> extends ClientProxy<T> implements stream.Readable {
@@ -154,6 +159,11 @@ export class Readable<T extends IReadableProxy = IReadableProxy> extends ClientP
 
 		return this;
 	}
+
+	protected handleDisconnect(): void {
+		this.emit("close");
+		this.emit("end");
+	}
 }
 
 export class Duplex<T extends DuplexProxy = DuplexProxy> extends Writable<T> implements stream.Duplex, stream.Readable {
@@ -230,4 +240,9 @@ export class Duplex<T extends DuplexProxy = DuplexProxy> extends Writable<T> imp
 
 		return this;
 	}
+
+	protected handleDisconnect(): void {
+		super.handleDisconnect();
+		this.emit("end");
+	}
 }

packages/protocol/src/common/proxy.ts

@@ -29,21 +29,48 @@ const unpromisify = <T extends ServerProxy>(proxyPromise: Promise<T>): T => {
  * need a bunch of `then` calls everywhere.
  */
 export abstract class ClientProxy<T extends ServerProxy> extends EventEmitter {
-	protected readonly proxy: T;
+	private _proxy: T | undefined;
 
 	/**
 	 * You can specify not to bind events in order to avoid emitting twice for
 	 * duplex streams.
 	 */
-	public constructor(proxyPromise: Promise<T> | T, bindEvents: boolean = true) {
+	public constructor(
+		proxyPromise: Promise<T> | T,
+		private readonly bindEvents: boolean = true,
+	) {
 		super();
-		this.proxy = isPromise(proxyPromise) ? unpromisify(proxyPromise) : proxyPromise;
-		if (bindEvents) {
+		this.initialize(proxyPromise);
+		if (this.bindEvents) {
+			this.on("disconnected", (error) => {
+				try {
+					this.emit("error", error);
+				} catch (error) {
+					// If nothing is listening, EventEmitter will throw an error.
+				}
+				this.handleDisconnect();
+			});
+		}
+	}
+
+	protected get proxy(): T {
+		if (!this._proxy) {
+			throw new Error("not initialized");
+		}
+
+		return this._proxy;
+	}
+
+	protected initialize(proxyPromise: Promise<T> | T): void {
+		this._proxy = isPromise(proxyPromise) ? unpromisify(proxyPromise) : proxyPromise;
+		if (this.bindEvents) {
 			this.proxy.onEvent((event, ...args): void => {
 				this.emit(event, ...args);
 			});
 		}
 	}
+
+	protected abstract handleDisconnect(): void;
 }
 
 /**

packages/protocol/src/node/server.ts

@@ -140,7 +140,7 @@ export class Server {
 		try {
 			const proxy = this.getProxy(proxyId);
 			if (typeof proxy.instance[method] !== "function") {
-				throw new Error(`"${method}" is not a function`);
+				throw new Error(`"${method}" is not a function on proxy ${proxyId}`);
 			}
 
 			response = proxy.instance[method](...args);