node/test/parallel/test-repl-pretty-custom-stack.js

'use strict';
require('../common');
const ArrayStream = require('../common/arraystream');
const fixtures = require('../common/fixtures');
const assert = require('assert');
const repl = require('repl');


function run({ command, expected }) {
  let accum = '';

  const inputStream = new ArrayStream();
  const outputStream = new ArrayStream();

  outputStream.write = (data) => accum += data.replace('\r', '');

  const r = repl.start({
    prompt: '',
    input: inputStream,
    output: outputStream,
    terminal: false,
    useColors: false
  });

  r.write(`${command}\n`);
  assert.strictEqual(accum, expected);
  r.close();
}

const origPrepareStackTrace = Error.prepareStackTrace;
Error.prepareStackTrace = (err, stack) => {
  if (err instanceof SyntaxError)
    return err.toString();
  stack.push(err);
  return stack.reverse().join('--->\n');
};

process.on('uncaughtException', (e) => {
  Error.prepareStackTrace = origPrepareStackTrace;
  throw e;
});

process.on('exit', () => (Error.prepareStackTrace = origPrepareStackTrace));

const tests = [
  {
    // test .load for a file that throws
    command: `.load ${fixtures.path('repl-pretty-stack.js')}`,
    expected: 'Thrown:\nError: Whoops!--->\nrepl:9:24--->\nd (repl:12:3)' +
              '--->\nc (repl:9:3)--->\nb (repl:6:3)--->\na (repl:3:3)\n'
  },
  {
    command: 'let x y;',
    expected: 'Thrown:\n' +
              'let x y;\n      ^\n\nSyntaxError: Unexpected identifier\n'
  },
  {
    command: 'throw new Error(\'Whoops!\')',
    expected: 'Thrown:\nError: Whoops!\n'
  },
  {
    command: 'foo = bar;',
    expected: 'Thrown:\nReferenceError: bar is not defined\n'
  },
  // test anonymous IIFE
  {
    command: '(function() { throw new Error(\'Whoops!\'); })()',
    expected: 'Thrown:\nError: Whoops!--->\nrepl:1:21\n'
  }
];

tests.forEach(run);