Remove the dynamic require() call in the standalone bundle

[j-f1]

Prettier will now throw an error if it can’t find the parser in the parsers object.

Fixes #4959.

• I’ve added tests to confirm my change works. ❓ How should I test this (if at all)?
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[ikatyang]

How about an early exit with BUNDLE_TARGET !== "node"?

if (process.env.BUNDLE_TARGET !== "node") {
  throw ...
}

try { ... }
catch (...) { ... }

[j-f1]

Unfortunately, that doesn’t work:

// built standalone.js
if (typeof opts.parser === "string") {
  if (parsers.hasOwnProperty(opts.parser)) {
    return parsers[opts.parser];
  }
  /* istanbul ignore next */

  {
    throw new ConfigError$1(
     "Couldn't resolve parser \"".concat(
        opts.parser,
        '". Parsers must be explicitly added to the standalone bundle.'
      )
    );
  }

  try {
    return {
      parse: require(path.resolve(process.cwd(), opts.parser)),
      astFormat: "estree",
      locStart: locStart,
      locEnd: locEnd
    };
  } catch (err) {
    /* istanbul ignore next */
    throw new ConfigError$1(
      "Couldn't resolve parser \"".concat(opts.parser, '"')
    );
  }
}