New shell backend

package.json

@@ -11,7 +11,7 @@
   },
   "scripts": {
     "build": "webpack --mode production && rm -rf dist/*.LICENSE.*",
-    "dev": "webpack watch --mode development"
+    "dev": "webpack watch --mode production"
   },
   "keywords": [
     "xterm.js",

src/Command.js

@@ -0,0 +1,17 @@
+export default class Command {
+  static PIPE = Symbol("PIPE")
+  static STDOUT = Symbol("STDOUT")
+  static STDERR = Symbol("STDERR")
+
+  name
+  argv
+
+  constructor(name, argv, io = null) {
+    this.name = name
+    this.argv = argv
+
+    this.stdout = io?.stdout ?? Command.STDOUT
+    this.stderr = io?.stderr ?? Command.STDERR
+    this.append = io?.append ?? false
+  }
+}

src/Errors.js

@@ -0,0 +1,38 @@
+export class CommandNotFoundError extends Error {
+  constructor(...params) {
+    super(...params)
+
+    // Maintains proper stack trace for where our error was thrown (non-standard)
+    if (Error.captureStackTrace) {
+      Error.captureStackTrace(this, CommandNotFoundError)
+    }
+
+    this.name = "CommandNotFoundError"
+  }
+}
+
+export class KeyboardInterruptError extends Error {
+  constructor(...params) {
+    super(...params)
+
+    // Maintains proper stack trace for where our error was thrown (non-standard)
+    if (Error.captureStackTrace) {
+      Error.captureStackTrace(this, KeyboardInterruptError)
+    }
+
+    this.name = "KeyboardInterruptError"
+  }
+}
+
+export class CommandParserError extends Error {
+  constructor(...params) {
+    super(...params)
+
+    // Maintains proper stack trace for where our error was thrown (non-standard)
+    if (Error.captureStackTrace) {
+      Error.captureStackTrace(this, CommandParserError)
+    }
+
+    this.name = "CommandParserError"
+  }
+}