Implement fs module (#3)

* Implements the fs module

* Add stats object

* Add not implemented to createWriteStream

* Update mkdtemp to use tmp dir

* Unexport Stats

* Add client web socket for commands and restructure

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

@@ -0,0 +1,52 @@
+import * as cp from "child_process";
+import { Client } from "../client";
+import { useBuffer } from "./util";
+
+export class CP {
+
+	public constructor(
+		private readonly client: Client,
+	) { }
+
+	public exec(
+		command: string,
+		options?: { encoding?: BufferEncoding | string | "buffer" | null } & cp.ExecOptions | null | ((error: Error | null, stdout: string, stderr: string) => void) | ((error: Error | null, stdout: Buffer, stderr: Buffer) => void),
+		callback?: ((error: Error | null, stdout: string, stderr: string) => void) | ((error: Error | null, stdout: Buffer, stderr: Buffer) => void),
+	): cp.ChildProcess {
+		const process = this.client.spawn(command);
+
+		let stdout = "";
+		process.stdout.on("data", (data) => {
+			stdout += data.toString();
+		});
+
+		let stderr = "";
+		process.stderr.on("data", (data) => {
+			stderr += data.toString();
+		});
+
+		process.on("exit", (exitCode) => {
+			const error = exitCode !== 0 ? new Error(stderr) : null;
+			if (typeof options === "function") {
+				callback = options;
+			}
+			// @ts-ignore not sure how to make this work.
+			callback(
+				error,
+				useBuffer(options) ? Buffer.from(stdout) : stdout,
+				useBuffer(options) ? Buffer.from(stderr) : stderr,
+			);
+		});
+
+		return process;
+	}
+
+	public fork(modulePath: string): cp.ChildProcess {
+		return this.client.fork(modulePath);
+	}
+
+	public spawn(command: string, args?: ReadonlyArray<string> | cp.SpawnOptions, _options?: cp.SpawnOptions): cp.ChildProcess {
+		return this.client.spawn(command, args, options);
+	}
+
+}