installer.js

module.exports = function(verbose) {
  var binstall = require("binstall");
  var path = require("path");
  var fs = require("fs");
  var packageInfo = require(path.join(__dirname, "package.json"));

  // Use major.minor.patch from version string - e.g. "1.2.3" from "1.2.3-alpha"
  var binVersion = packageInfo.version.match(/^(\d+\.\d+\.\d+).*$/)[1];

  // 'arm', 'ia32', or 'x64'.
  var arch = process.arch;

  // 'darwin', 'freebsd', 'linux', 'sunos' or 'win32'
  var operatingSystem = process.platform;

  var filename = operatingSystem + "-" + arch + ".tar.gz";
  var url = "https://dl.bintray.com/elmlang/elm-test/" +
    binVersion +
    "/" +
    filename;

  var binariesDir = path.join(__dirname, "bin");
  var packageInfo = require(path.join(__dirname, "package.json"));
  var binaryExtension = process.platform === "win32" ? ".exe" : "";
  var executablePaths = [
    path.join(binariesDir, "elm-interface-to-json" + binaryExtension)
  ];
  var errorMessage = "Unfortunately, there are no elm-test " +
    binVersion +
    " binaries available on your operating system and architecture.\n\nIf you would like to build Elm from source, there are instructions at https://github.com/elm-lang/elm-platform#build-from-source\n";

  return binstall(
    url,
    { path: binariesDir },
    {
      verbose: verbose,
      verify: executablePaths,
      errorMessage: errorMessage
    }
  );
};