make dist absolutePath browser-safe, add test

swagger-ui-dist-package/absolute-path.js

@@ -0,0 +1,14 @@
+/*
+ * getAbsoluteFSPath
+ * @return {string} When run in NodeJS env, returns the absolute path to the current directory
+ *                  When run outside of NodeJS, will return an error message
+ */
+const getAbsoluteFSPath = () => {
+  // detect whether we are running in a browser or nodejs
+  if (typeof module !== "undefined" && module.exports) {
+    return require("path").resolve(__dirname)
+  }
+  return "Error! absolutePath only available when running in NodeJS"
+}
+
+module.exports = getAbsoluteFSPath()