r3bl-ts-utils/src/tui-core/ink-main-helper.ts

The `r3bl-ts-utils` package is a set of useful TypeScript functions and classes that can be used in Node.js and browser environments. They are inspired by Kotlin stdlib, and Rust to write code as expressions rather than statements, colorized text, powerfu

/*
 * Copyright (c) 2022 R3BL LLC. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

import EventEmitter from "events"
import { render } from "ink"
import { TimerRegistry } from "../timer-utils"
import { TextColor } from "../tui-colors"

/**
 * Launches a CLI app. This is the "bootloader" equivalent for a CLI app.
 *
 * If you have any event listeners attached (eg, using `useKeyboard()`, or `useNodeKeypress()`) then
 * your app won't exit if you don't call `LifecycleHelper.fireExit()`.
 *
 * Usage example:
 * ```tsx
 * const App:FC = ()=> {
 *   const createShortcutsFn = (): ShortcutToActionMap =>
 *     _also(
 *       createNewShortcutToActionMap(),
 *       map => map.set("q", LifecycleHelper.fireExit)
 *     )
 *   useKeyboardWithMapCached(createShortcutsFn)
 *   return( <Text>"Hello"</Text> )
 * }
 *
 * inkCLIAppMainFn( ()=>{
 *   const args = processCommandLineArgs()
 *   return createInkApp(args)
 * } ).catch(console.error)
 * ```
 *
 * @param {() => ReturnType<typeof render>} runFn Do what you need to create an Ink instance
 * @param okExitMsg If non empty string (truthy) display this on exit w/out errors
 * @param errExitMsg If non empty string (truthy) display this on exit w/ errors
 * @return {Promise<void>} Optionally attach a catch block to this promise
 */
export const inkCLIAppMainFn = async (
  runFn: () => ReturnType<typeof render>,
  okExitMsg = "",
  errExitMsg = ""
): Promise<void> => {
  const instance = runFn()

  LifecycleHelper.addExitListener(() => {
    TimerRegistry.killAll()
    instance.unmount()
  })

  try {
    await instance.waitUntilExit()
    if (okExitMsg) console.log(TextColor.builder.bgYellow.black.build()(okExitMsg))
  } catch (err) {
    if (errExitMsg) console.error(TextColor.builder.bgYellow.black.build()(errExitMsg))
  }
}

// LifecycleHelper.

type EventName = "exit" | "start"
type EventListener = (name: EventName) => void

export class LifecycleHelper extends EventEmitter {
  static instance = new LifecycleHelper()

  static addStartListener = (listener: EventListener) => this.instance.on("start", listener)
  static addExitListener = (listener: EventListener) => this.instance.on("exit", listener)

  static fireExit = () => this.instance.emit("exit")
  static fireStart = () => this.instance.emit("start")

  static removeAll = () => this.instance.removeAllListeners()
}