public-path.js

exports.setPublicPath = function setPublicPath(
  systemjsModuleName,
  rootDirectoryLevel
) {
  if (!rootDirectoryLevel) {
    rootDirectoryLevel = 1;
  }
  if (
    typeof systemjsModuleName !== "string" ||
    systemjsModuleName.trim().length === 0
  ) {
    throw Error(
      "systemjs-webpack-interop: setPublicPath(systemjsModuleName) must be called with a non-empty string 'systemjsModuleName'"
    );
  }

  if (
    typeof rootDirectoryLevel !== "number" ||
    rootDirectoryLevel <= 0 ||
    isNaN(rootDirectoryLevel) ||
    !isInteger(rootDirectoryLevel)
  ) {
    throw Error(
      "systemjs-webpack-interop: setPublicPath(systemjsModuleName, rootDirectoryLevel) must be called with a positive integer 'rootDirectoryLevel'"
    );
  }

  var moduleUrl;
  try {
    moduleUrl = window.System.resolve(systemjsModuleName);
    if (!moduleUrl) {
      throw Error();
    }
  } catch (err) {
    throw Error(
      "systemjs-webpack-interop: There is no such module '" +
        systemjsModuleName +
        "' in the SystemJS registry. Did you misspell the name of your module?"
    );
  }

  __webpack_public_path__ = resolveDirectory(moduleUrl, rootDirectoryLevel);
};

function resolveDirectory(urlString, rootDirectoryLevel) {
  // Our friend IE11 doesn't support new URL()
  // https://github.com/single-spa/single-spa/issues/612
  // https://gist.github.com/jlong/2428561

  var a = document.createElement("a");
  a.href = urlString;

  var pathname = a.pathname[0] === "/" ? a.pathname : "/" + a.pathname;
  var numDirsProcessed = 0,
    index = pathname.length;
  while (numDirsProcessed !== rootDirectoryLevel && index >= 0) {
    var char = pathname[--index];
    if (char === "/") {
      numDirsProcessed++;
    }
  }

  if (numDirsProcessed !== rootDirectoryLevel) {
    throw Error(
      "systemjs-webpack-interop: rootDirectoryLevel (" +
        rootDirectoryLevel +
        ") is greater than the number of directories (" +
        numDirsProcessed +
        ") in the URL path " +
        urlString
    );
  }

  var finalPath = pathname.slice(0, index + 1);

  return a.protocol + "//" + a.host + finalPath;
}

exports.resolveDirectory = resolveDirectory;

// borrowed from https://github.com/parshap/js-is-integer/blob/master/index.js
var isInteger =
  Number.isInteger ||
  function isInteger(val) {
    return typeof val === "number" && isFinite(val) && Math.floor(val) === val;
  };