babel-preset-expo-modern

Babel preset for Expo that won't transpile all the way back to ES5

Using the default expo/metro preset for Babel will yield you code that's pretty portable, but uses more transforms than are strictly necessary. Modern browsers support destructuring, computed properties, ES6 classes, arrow functions, for-of, and a slew of other features that are transpiled away by metro-react-native-babel-preset. Simply by not doing that, we can emit better source maps and cleaner code for debugging.

Included transforms

These syntax elements will be transpiled away

• Expo vector icons transform
• Flow syntax
• Decorators
• Class properties
• Nullish coalescing
• Optional chaining
• Optional catch binding
• Dynamic import
• Export default from
• JSX
• JSX sourcemap
• TypeScript
• (optionally) Import/export => CommonJS

Removed transforms (present in metro)

Use metro/expo preset if you use these syntax elements AND your target browser doesn't support them.

• Block scoping
• Computed properties
• Destructuring
• Integer literals
• Rest/default parameters
• Shorthand properties
• Sticky regex
• Unicode regex
• Arrow functions
• ES6 classes
• For-of
• Spread
• Template literals
• Exponentiation operator
• Object.assign
• Object rest/spread
• Symbol members