find file with wild card matching

If glob is not quite what you want, or a little confusing, there is also glob-fs. The documentation covers many usage scenarios with examples.

// sync 
var files = glob.readdirSync('*.js', {});

// async 
glob.readdir('*.js', function(err, files) {
  console.log(files);
});

// stream 
glob.readdirStream('*.js', {})
  .on('data', function(file) {
    console.log(file);
  });

// promise 
glob.readdirPromise('*.js')
  .then(function(files) {
    console.log(file);
  });

If you don't want to add a new dependency to your project (like glob), you can use plain js/node functions, like:

var files = fs.readdirSync('C:/tmp').filter(fn => fn.endsWith('.csv'));

Regex may help in more complex comparisons

This is not covered by Node core. You can check out this module for what you are after.

Setup

npm i glob

Usage

var glob = require("glob")

// options is optional
glob("**/*.js", options, function (er, files) {
  // files is an array of filenames.
  // If the `nonull` option is set, and nothing
  // was found, then files is ["**/*.js"]
  // er is an error object or null.
})