get-user-code-frame.js 1.76 KB
"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.getUserCodeFrame = getUserCodeFrame;
// We try to load node dependencies
let chalk = null;
let readFileSync = null;
let codeFrameColumns = null;

try {
  const nodeRequire = module && module.require;
  readFileSync = nodeRequire.call(module, 'fs').readFileSync;
  codeFrameColumns = nodeRequire.call(module, '@babel/code-frame').codeFrameColumns;
  chalk = nodeRequire.call(module, 'chalk');
} catch {// We're in a browser environment
} // frame has the form "at myMethod (location/to/my/file.js:10:2)"


function getCodeFrame(frame) {
  const locationStart = frame.indexOf('(') + 1;
  const locationEnd = frame.indexOf(')');
  const frameLocation = frame.slice(locationStart, locationEnd);
  const frameLocationElements = frameLocation.split(':');
  const [filename, line, column] = [frameLocationElements[0], parseInt(frameLocationElements[1], 10), parseInt(frameLocationElements[2], 10)];
  let rawFileContents = '';

  try {
    rawFileContents = readFileSync(filename, 'utf-8');
  } catch {
    return '';
  }

  const codeFrame = codeFrameColumns(rawFileContents, {
    start: {
      line,
      column
    }
  }, {
    highlightCode: true,
    linesBelow: 0
  });
  return `${chalk.dim(frameLocation)}\n${codeFrame}\n`;
}

function getUserCodeFrame() {
  // If we couldn't load dependencies, we can't generate the user trace

  /* istanbul ignore next */
  if (!readFileSync || !codeFrameColumns) {
    return '';
  }

  const err = new Error();
  const firstClientCodeFrame = err.stack.split('\n').slice(1) // Remove first line which has the form "Error: TypeError"
  .find(frame => !frame.includes('node_modules/')); // Ignore frames from 3rd party libraries

  return getCodeFrame(firstClientCodeFrame);
}