typescriptFormatter.js

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

'use strict';

const os = require('os');
const codeFrame = require('@babel/code-frame').codeFrameColumns;
const chalk = require('chalk');
const fs = require('fs');

function formatter(message, useColors) {
  const colors = new chalk.constructor({ enabled: useColors });
  const messageColor = message.isWarningSeverity() ? colors.yellow : colors.red;

  const source =
    message.getFile() &&
    fs.existsSync(message.getFile()) &&
    fs.readFileSync(message.getFile(), 'utf-8');
  let frame = '';

  if (source) {
    frame = codeFrame(
      source,
      { start: { line: message.line, column: message.character } },
      { highlightCode: useColors }
    )
      .split('\n')
      .map(str => '  ' + str)
      .join(os.EOL);
  }

  return [
    messageColor.bold(`Type ${message.getSeverity().toLowerCase()}: `) +
      message.getContent() +
      '  ' +
      messageColor.underline(`TS${message.code}`),
    '',
    frame,
  ].join(os.EOL);
}

module.exports = formatter;