Detox

Detox

Detox is designed for React Native. Unlike Appium (Black-box), Detox works "Gray-box" by running inside your app, monitoring the main thread. It knows when the app is busy/idle, eliminating flaky waits.

When to Use

• React Native Apps: The gold standard for RN E2E.
• Speed & Stability: Much less flaky than Appium for RN because of synchronization.
• CI/CD: Designed to be fast enough for CI.

Quick Start

describe("Example", () => {
  beforeAll(async () => {
    await device.launchApp();
  });

  it("should show hello screen after tap", async () => {
    await element(by.id("hello_button")).tap();
    await expect(element(by.text("Hello!!!"))).toBeVisible();
  });
});

Core Concepts

Synchronization

Detox monitors network requests, animations, and timers. It waits for the app to go "Idle" before executing the next command. No sleep() needed.

Matchers

by.id(), by.text(), by.label(). Needs testID props on React Native components.

Best Practices (2025)

Do:

• Add testID props: Add them to all interactive elements in your React Native code.
• Use device.reloadReactNative(): Faster than relaunching the whole app for every test.
• Mock Metro: Mock JS bundles to avoid network flakes in CI.

Don't:

• Don't run animations: Disable them in the test build for speed and stability.
• Don't combine with Appium: Choose one for your project.

References

• Detox Documentation