This repository demonstrates a memory leak in the Firebase Javascript (NPM) client.

To reproduce the problem:

• Check out this repo
• Run yarn in the project root
• Run expo start to start the Expo runner (you need expo-cli, yarn global add expo-cli)
• Open the project on the iOS simulator (by pressing the "i" key in the console where expo start runs) or on a device (by downloading the "Expo Go" app and then scanning the QR code in the expo start browser with the camera)
• Shake the device to turn on the Performance Monitor
• Memory usage on startup will be around 450 MB
• Press "Load Pages" to load 1'000 documents of 100 kB each from Firestore
• Memory usage will go to 2.5 - 3 GB
• Shut down the app (by swiping it up in the app-switcher, or by killing the "Expo Go" process in MacOS Activity Monitor)
• Start the app again
• Press "Load Pages" again. This time the documents are loaded from AsyncStorage
• Note the much lower memory consumption

If you get "Quota exceeded" errors, just try again, or play around with the number of documents to be loaded (line 19 App.js).

Conclusion: to load 100 MB of documents from Firestore, the Firebase client needs more than 2 GB of memory. This memory is not released, it cannot be garbage collected after the data load has finished.