set global.Blob to global.originalBlob before deleting global.Blob for rn > 0.54 compatability (#246)

Author: CNDW

app/worker/setup.js

@@ -12,6 +12,13 @@ self.global = self;
  * it will used for `whatwg-fetch` on older RN versions
  */
 if (self.Blob && self.Blob.toString() === 'function Blob() { [native code] }') {
+  /*
+   * RN > 0.54 will polyfill Blob.
+   * If it is deleted before the RN setup, RN will not add a reference to the original.
+   * We will need to be able to restore the original when running RN > 0.54 for networking tools,
+   * so add the reference here as react-native will not do it if the original is deleted
+   */
+  self.originalBlob = self.Blob;
   delete self.Blob;
 }
 

docs/network-inspect-of-chrome-devtools.md

@@ -15,6 +15,12 @@ global.XMLHttpRequest = global.originalXMLHttpRequest ?
 global.FormData = global.originalFormData ?
   global.originalFormData :
   global.FormData;
+global.Blob = global.originalBlob ?
+  global.originalBlob :
+  global.Blob;
+global.FileReader = global.originalFileReader ?
+  global.originalFileReader :
+  global.FileReader;
 ```
 
 This allows you can open the `Network` tab in devtools to inspect requests of `fetch` and `XMLHttpRequest`.