Walk a directory recursively but in order from top to bottom to find the specified file synchronously.

find.js

var fs   = require('fs')
  , path = require('path');

function find(dir, search, exclude) {
  var full        = null
    , stat        = null
    , directories = []
    , directory, contents, i, j;

  exclude = exclude || [];

  if (!fs.existsSync(dir)) return null;

  if (fs.statSync(dir).isFile()) {
    if (dir === search) return dir;
    return null;
  }

  contents = fs.readdirSync(dir);

  for (i = 0; i < contents.length; i++) {
    if (exclude.indexOf(contents[i]) >= 0) continue;

    full = path.join(dir, contents[i]);
    stat = fs.lstatSync(full);

    if (stat.isSymbolicLink()) continue;

    if (stat.isDirectory()) {
      directories.push(full);
      continue;
    }

    if (contents[i] === search) return full;
  }

  while (directory = directories.pop()) {
    contents = fs.readdirSync(directory);

    for (j = 0; j < contents.length; j++) {
      if (exclude.indexOf(contents[j]) >= 0) continue;
      full = path.join(directory, contents[j]);
      stat = fs.lstatSync(full);

      if (stat.isSymbolicLink()) continue;

      if (stat.isDirectory()) {
        directories.push(full);
        continue;
      }

      if (contents[j] === search) return path.join(directory, contents[j]);
    }
  }

  return null;
}

var found = find(process.argv[2], process.argv[3], process.argv[4]);
console.log('found', found);

Made this into a module

https://github.com/fiveisprime/find-file-sync