draft: refactor project so it sits on top of a standalone app

zero.Web.UI/node_modules/webpack-dev-server/lib/utils/findPort.js

@@ -0,0 +1,39 @@
+'use strict';
+
+const pRetry = require('p-retry');
+const portfinder = require('portfinder');
+const defaultPort = require('./defaultPort');
+const defaultTo = require('./defaultTo');
+const tryParseInt = require('./tryParseInt');
+
+function runPortFinder() {
+  return new Promise((resolve, reject) => {
+    portfinder.basePort = defaultPort;
+    portfinder.getPort((error, port) => {
+      if (error) {
+        return reject(error);
+      }
+
+      return resolve(port);
+    });
+  });
+}
+
+function findPort(port) {
+  if (port) {
+    return Promise.resolve(port);
+  }
+
+  // Try to find unused port and listen on it for 3 times,
+  // if port is not specified in options.
+  // Because NaN == null is false, defaultTo fails if parseInt returns NaN
+  // so the tryParseInt function is introduced to handle NaN
+  const defaultPortRetry = defaultTo(
+    tryParseInt(process.env.DEFAULT_PORT_RETRY),
+    3
+  );
+
+  return pRetry(runPortFinder, { retries: defaultPortRetry });
+}
+
+module.exports = findPort;