@rawcmd/core/src/streamlets/console.ts

Rawcmd core package.

import { EOL } from '@rawcmd/text';
import { toString } from '@rawcmd/utils';
import { StreamletBase } from '../types';

/**
 * Console streamlet prints messages directly to TTY console.
 */
export class ConsoleStreamlet implements StreamletBase {

  /**
   * Returns TTY screen width as number of columns.
   */
  public get width(): number {
    return process.stdout.columns;
  }

  /**
   * Returns TTY screen height as number of rows.
   */
  public get height(): number {
    return process.stdout.rows;
  }

  /**
   * Appends message to TTY buffer.
   * @param chunk Arbitrary message.
   */
  public write(chunk: string): boolean {
    return process.stdout.write(
      (toString(chunk) || '').replace(/\r\n|\n/g, EOL),
    );
  }

  /**
   * Removes the content of the last written row.
   * @param chunk Arbitrary message.
   */
  public clearLine(): boolean {
    return (
      !process.stdout.isTTY
      || (
        process.stdout['cursorTo'](0)
        && process.stdout['clearLine'](1)
      )
    );
  }

}