expo-modules

Great module standards

• Design native APIs as if you contributing W3C specs for the browser, take inspiration from modern web modules. eg std:kv-storage, clipboard.
• Aim for 100% backwards compatibility like the web.
• Create escape hatches for single-platform functionality.
• Avoid extraneous abstractions. Directly expose native functionality.
• Avoid unnecessary async methods. Use sync methods when possible.
• Prefer string union types for API options instead of boolean flags, enums, or multiple parameters. eg instead of capture(options: { isHighQuality: boolean }), use capture(options: { quality: 'high' | 'medium' | 'low' }).
• Marshalling is awesome for platform-specific APIs.
• New Architecture only. NEVER support legacy React Native architecture.
• ALWAYS use only Expo modules API.
• Prefer Swift and Kotlin.
• Use optionality for availability checks as opposed to extraneous isAvailable functions or constants. eg snapshot.capture?.() instead of snapshot.isAvailable && snapshot.capture().
• ALWAYS support the latest and greatest API features.

Example of a GREAT Expo module:

import { NativeModule } from "expo";