Interrupt Testing: Bulletproof Your App for the Real World...

Written by Fidel V | Chief Innovation Architect

In today's ruthless app ecosystem, crash reports and one-star reviews are only a swipe away. As someone who’s engineered apps for extreme environments—from enterprise-grade SaaS to aerospace-grade edge computing—I'll tell you this: interrupt testing isn't just a checkbox—it’s survival.

This article isn't fluff. It's based on real, production-grade engineering, and I'll walk you through a complete demo project that shows how to bulletproof your mobile app against the real-world chaos of interruptions—calls, texts, network drops, lock screens, and rogue battery alerts. Expect reusable, clean code with sharp notations. Every line written with production troubleshooting in mind.

Let’s make sure your app doesn’t fold when life hits the pause button.

Why Interrupt Testing Matters

Imagine this:

• A customer is checking out on your app. Suddenly—ring ring, a phone call.
• They return—the cart is empty.

That's not just poor UX—that's lost revenue, negative reviews, and churn.

Interrupt testing ensures:

• Session continuity
• No silent crashes
• Confidence under any OS or hardware condition

Interrupts = Revenue Killers (if ignored) | Trust Builders (if handled)

Real-World Chaos Scenarios

Here are the types of real-world chaos we simulate and defend against:

      < Interrupt  >                   < Type Common Risk > 
>> Incoming Calls        ||   App paused → user flow lost 
>> Network Switch      ||   Request fails → corrupted response 
>> Battery Alerts         ||   Force-close → unsaved data lost 
>> Lock Screen           ||   Background state mishandling 
>> App Switching       ||   Lost context or media playback issues 
Notification Spam       ||   Overlay interrupts logic/UI        

Project: Interrupt-Resilient Mobile App

We'll build a React Native + TypeScript mobile app that plays a video and saves playback state across lifecycle events.

Use Case

User watches a video → receives a call → returns to app → playback resumes at exact timestamp.

Project Structure

shell


InterruptSafePlayer/
├── App.tsx
├── utils/
│   └── storage.ts
├── hooks/
│   └── useAppLifecycle.ts
├── components/
│   └── ResilientVideo.tsx
├── types/
│   └── index.ts
        

App.tsx – Entry Point

tsx


import React from 'react';
import { SafeAreaView } from 'react-native';
import ResilientVideo from './components/ResilientVideo';

export default function App() {
  return (
    <SafeAreaView style={{ flex: 1 }}>
      <ResilientVideo />
    </SafeAreaView>
  );
}
        

ResilientVideo.tsx – Graceful Video Handling

tsx



import React, { useRef, useState, useEffect } from 'react';
import Video from 'react-native-video';
import { AppState } from 'react-native';
import { storePosition, getPosition } from '../utils/storage';

const VIDEO_URL = 'https://path-to-your-video.mp4';

export default function ResilientVideo() {
  const videoRef = useRef(null);
  const [position, setPosition] = useState(0);

  useEffect(() => {
    getPosition().then(setPosition);
  }, []);

  useEffect(() => {
    const subscription = AppState.addEventListener('change', async (state) => {
      if (state !== 'active') {
        await storePosition(position);
      }
    });

    return () => subscription.remove();
  }, [position]);

  return (
    <Video
      ref={videoRef}
      source={{ uri: VIDEO_URL }}
      onProgress={({ currentTime }) => setPosition(currentTime)}
      paused={false}
      resizeMode="contain"
      controls
      style={{ flex: 1 }}
      progressUpdateInterval={500}
    />
  );
}
        

storage.ts – Persistent Local Save

ts


import AsyncStorage from '@react-native-async-storage/async-storage';

const KEY = 'VIDEO_POSITION';

export const storePosition = async (pos: number) => {
  try {
    await AsyncStorage.setItem(KEY, pos.toString());
  } catch (e) {
    console.error('Error saving position:', e);
  }
};

export const getPosition = async (): Promise<number> => {
  try {
    const val = await AsyncStorage.getItem(KEY);
    return val ? parseFloat(val) : 0;
  } catch (e) {
    console.error('Error retrieving position:', e);
    return 0;
  }
};
        

useAppLifecycle.ts – Lifecycle Event Tracker

ts


import { useEffect } from 'react';
import { AppState } from 'react-native';

export const useAppLifecycle = (onPause: () => void, onResume: () => void) => {
  useEffect(() => {
    const subscription = AppState.addEventListener('change', (state) => {
      if (state === 'background') onPause();
      else if (state === 'active') onResume();
    });

    return () => subscription.remove();
  }, []);
};
        

Busting Common Myths

{ Myth } { Reality }

It works on my device <> Test across OS versions, brands, RAM profiles"One lifecycle handler is enough <> You need onPause, onStop, onResume, onDestroy, etc."Users don't mind minor crashes X They uninstall. Then leave 1-star reviews. Then warn others.

What Interrupt Testing Looks Like in Practice

Test Scenario Expected Result Receive a call mid-video Playback paused, resumed correctly after return Lock screen during form entry Form state saved, restored on resume Lose Wi-Fi mid-API call Retry logic queues request, sends when online Switch app and return App remembers UI state & context

Automation: E2E Testing with Detox

bash


npm install --save-dev detox
        

Sample interrupt simulation:

ts


describe('Interrupt Handling', () => {
  it('pauses video on call simulation', async () => {
    await device.launchApp();
    await element(by.id('video')).tap();
    await device.sendToHome(); // Simulate interrupt
    await device.launchApp();
    await expect(element(by.id('resume-button'))).toBeVisible();
  });
});
        

The Engineering Mindset

Interrupt testing isn't a separate step. It’s a mindset:

• Build for chaos → Expect the unexpected.
• Design defensively → Always assume your app could be paused.
• Test aggressively → Simulate what users will never tell you.

Wrapping It Up

Interrupt testing is your superpower.

It separates amateurs from professionals. If you want to build real apps that users trust—even when life gets messy—you can’t ignore it.

You’re not just fixing bugs. You’re engineering trust.

Demo Disclaimer: This project is for demonstration and training purposes only. For production use, integrate it with crash reporting (Sentry/Firebase Crashlytics), CI/CD pipelines, and test on multiple hardware profiles via BrowserStack or Firebase Test Lab.

Want to go deeper? I offer consulting to bring this interrupt resilience into your product roadmap. Let’s build software that thrives in the real world.