remove some auto-generated error messages in "assert.throws" tests

[bakkot]

Per #4017 (comment), this (automatically) rewrites a bunch of tests to remove auto-generated error messages in various assert.throws tests.

There's still a handful left but this deals with most of them.

rewrite-test262.mjs

import fs from 'node:fs';
import path from 'node:path';

if (process.argv.length !== 3) {
  console.log('Usage: node rewrite-test262.mjs path-to-test262');
  process.exit(1);
}

let dir = process.argv[2];

let matches = 0;
let files = [...fs.readdirSync(dir, { recursive: true, withFileTypes: true })];
for (let i = 0; i < files.length; ++i) {
  let file = files[i];
  if (!file.isFile()) continue;
  let fname = path.join(file.parentPath, file.name);
  let content = fs.readFileSync(fname, 'utf8');

  let regexpSrc = String.raw`
(?<main>assert.throws\( (?<kind>[A-Za-z0-9]+), (function \(\)|\(\) =>) \{
  (?<code>[^}]*|.*)
\})\, "\`(?<code2>[^\`]+)\` throws \k<kind>" \);
`
    .trim()
    .replace(/\\`/g, '`')
    .replace(/\s+/g, '\\s*')
    .replace(/"/g, '["\']');
  let regexp = new RegExp(regexpSrc);

  let match = regexp.exec(content);
  if (match) {
    let { groups } = match;
    let { code, code2} = groups;
    code = code.trim().replace(/\s+/g, '');
    code2 = code2.trim().replace(/\\'/g, "'").replace(/\s+/g, '');
    if (code.endsWith(';')) code = code.slice(0, -1);
    if (code2 !== code) continue;

    ++matches;

    let replacement = `${groups.main});`
    content = content.slice(0, match.index) + replacement + content.slice(match.index + match[0].length);

    fs.writeFileSync(fname, content, 'utf8');
    --i; // re-run on this file in case there was more than one
  }
}
console.log(`rewrote ${matches} instances`);

[ljharb]

certainly we don't need an error message that just replicates the code that throws :-)