fix: self and global error in alipay appx (mobxjs#2071)

* fix: self and global error in alipay appx

* Updated changelog

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 5.13.1 / 4.13.1
+
+* Don't use `global` and `self` keywords unless defined. Fixes [#2070](https://github.com/mobxjs/mobx/issues/2070).
+
 # 5.13.0 / 4.13.0
 
 * Fixed potential memory leak in observable maps, when non-primitive values are used as keys. Fixes [#2031](https://github.com/mobxjs/mobx/issues/2031) through [#2032](https://github.com/mobxjs/mobx/pull/2032).

src/core/globalstate.ts

@@ -180,6 +180,14 @@ export function resetGlobalState() {
 
 declare const window: any
 
+const mockGlobal = {}
+
 export function getGlobal() {
-    return typeof window !== "undefined" ? window : global
+    if (typeof window !== "undefined") {
+        return window
+    }
+    if (typeof global !== "undefined") {
+        return global
+    }
+    return mockGlobal
 }

src/utils/iterable.ts

@@ -1,8 +1,8 @@
 export function makeIterable<T>(iterator: Iterator<T>): IterableIterator<T> {
-    iterator[Symbol.iterator] = self
+    iterator[Symbol.iterator] = getSelf
     return iterator as any
 }
 
-function self() {
+function getSelf() {
     return this
 }