Fix coping and moving files around using the file tree (#568)

* Implement write/read buffers in electron fill

This makes cutting and copy files from the file tree work.

* Implement fs.createReadStream

This is used by the file tree to copy files.

* Allow passing proxies back from client to server

This makes things like piping streams possible.

* Synchronously bind to proxy events

This eliminates any chance whatsoever of missing events due to binding
too late.

* Make it possible to bind some events on demand

* Add some protocol documentation

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

@@ -9,18 +9,25 @@ import { preserveEnv } from "../../common/util";
 /**
  * Server-side IPty proxy.
  */
-export class NodePtyProcessProxy implements ServerProxy {
-	private readonly emitter = new EventEmitter();
-
+export class NodePtyProcessProxy extends ServerProxy {
 	public constructor(private readonly process: pty.IPty) {
+		super({
+			bindEvents: ["process", "data", "exit"],
+			doneEvents: ["exit"],
+			instance: new EventEmitter(),
+		});
+
+		this.process.on("data", (data) => this.instance.emit("data", data));
+		this.process.on("exit", (exitCode, signal) => this.instance.emit("exit", exitCode, signal));
+
 		let name = process.process;
 		setTimeout(() => { // Need to wait for the caller to listen to the event.
-			this.emitter.emit("process", name);
+			this.instance.emit("process", name);
 		}, 1);
 		const timer = setInterval(() => {
 			if (process.process !== name) {
 				name = process.process;
-				this.emitter.emit("process", name);
+				this.instance.emit("process", name);
 			}
 		}, 200);
 
@@ -47,21 +54,10 @@ export class NodePtyProcessProxy implements ServerProxy {
 		this.process.write(data);
 	}
 
-	public async onDone(cb: () => void): Promise<void> {
-		this.process.on("exit", cb);
-	}
-
 	public async dispose(): Promise<void> {
 		this.process.kill();
 		setTimeout(() => this.process.kill("SIGKILL"), 5000); // Double tap.
-		this.emitter.removeAllListeners();
-	}
-
-	// tslint:disable-next-line no-any
-	public async onEvent(cb: (event: string, ...args: any[]) => void): Promise<void> {
-		this.emitter.on("process", (process) => cb("process", process));
-		this.process.on("data", (data) => cb("data", data));
-		this.process.on("exit", (exitCode, signal) => cb("exit", exitCode, signal));
+		await super.dispose();
 	}
 }