Mobile App Testing

Table of Contents

• Overview
• When to Use
• Quick Start
• Reference Guides
• Best Practices

Overview

Implement comprehensive testing strategies for mobile applications including unit tests, UI tests, integration tests, and performance testing.

When to Use

• Creating reliable mobile applications with test coverage
• Automating UI testing across iOS and Android
• Performance testing and optimization
• Integration testing with backend services
• Regression testing before releases

Quick Start

Minimal working example:

// Unit test with Jest
import { calculate } from "../utils/math";

describe("Math utilities", () => {
  test("should add two numbers", () => {
    expect(calculate.add(2, 3)).toBe(5);
  });

  test("should handle negative numbers", () => {
    expect(calculate.add(-2, 3)).toBe(1);
  });
});

// Component unit test
import React from "react";
import { render, screen } from "@testing-library/react-native";
import { UserProfile } from "../components/UserProfile";

describe("UserProfile Component", () => {
  test("renders user name correctly", () => {
    const mockUser = { id: "1", name: "John Doe", email: "john@example.com" };
    render(<UserProfile user={mockUser} />);

    expect(screen.getByText("John Doe")).toBeTruthy();
  });
// ... (see reference guides for full implementation)

Reference Guides

Detailed implementations in the references/ directory:

Guide	Contents
React Native Testing with Jest & Detox	React Native Testing with Jest & Detox
iOS Testing with XCTest	iOS Testing with XCTest
Android Testing with Espresso	Android Testing with Espresso
Performance Testing	Performance Testing

Best Practices

✅ DO

• Write tests for business logic first
• Use dependency injection for testability
• Mock external API calls
• Test both success and failure paths
• Automate UI testing for critical flows
• Run tests on real devices
• Measure performance on target devices
• Keep tests isolated and independent
• Use meaningful test names
• Maintain >80% code coverage

❌ DON'T

• Skip testing UI-critical flows
• Use hardcoded test data
• Ignore performance regressions
• Test implementation details
• Make tests flaky or unreliable
• Skip testing on actual devices
• Ignore accessibility testing
• Create interdependent tests
• Test without mocking APIs
• Deploy untested code