Adding support for web workers, and react-native

closes #70, closes #98

lib/utils.js

@@ -140,6 +140,27 @@ function isArguments(val) {
   return toString.call(val) === '[object Arguments]';
 }
 
+/**
+ * Determine if we're running in a standard browser environment
+ *
+ * This allows axios to run in a web worker, and react-native.
+ * Both environments support XMLHttpRequest, but not fully standard globals.
+ *
+ * web workers:
+ *  typeof window -> undefined
+ *  typeof document -> undefined
+ *
+ * react-native:
+ *  typeof document.createelement -> undefined
+ */
+function isStandardBrowserEnv() {
+  return (
+    typeof window !== 'undefined' &&
+    typeof document !== 'undefined' &&
+    typeof document.createElement === 'function'
+  );
+}
+
 /**
  * Iterate over an Array or an Object invoking a function for each item.
  *
@@ -221,6 +242,7 @@ module.exports = {
   isDate: isDate,
   isFile: isFile,
   isBlob: isBlob,
+  isStandardBrowserEnv: isStandardBrowserEnv,
   forEach: forEach,
   merge: merge,
   trim: trim