How to configure a `lib` option of tsconfig.json for React Native

By default official react native typescript template and @tsconfig/react-native uses "lib": ["es2017"]

If you want to set newer level the next tables can help you identify an individual library component or to know what iOS version supports new functions/proposals

Note:

• React Native on Android will use a JavaScriptCore version from npm jsc-android

• React Native on iOS will use JavaScriptCore that provided by operating system. So, different iOS versions include a different JSC engine

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es2020

Android (RN version)	0.60.x	0.61.x	0.62.x	0.63.x	0.64.x	0.65.x
BigInt (es2020.bigint)	❌	❌	❌	❌	❌	❌
BigInt64Array (es2020.bigint)	❌	❌	❌	❌	❌	❌
BigUint64Array (es2020.bigint)	❌	❌	❌	❌	❌	❌
Promise.allSettled() (es2020.promise)	❌	❌	❌	❌	❌	❌
str.matchAll(/regex/g) (es2020.string)	✅	✅	✅	✅	✅	✅
Symbol.matchAll (es2020.symbol.wellknown)	✅	✅	✅	✅	✅	✅

iOS version	11.0	11.4	12.0	12.4	13.0	14.4
BigInt (es2020.bigint)	❌	❌	❌	❌	❌	✅
BigInt64Array (es2020.bigint)	❌	❌	❌	❌	❌	❌
BigUint64Array (es2020.bigint)	❌	❌	❌	❌	❌	❌
Promise.allSettled() (es2020.promise)	❌	❌	❌	❌	❌	❌
str.matchAll(/regex/g) (es2020.string)	❌	❌	❌	❌	✅	✅
Symbol.matchAll (es2020.symbol.wellknown)	❌	❌	❌	❌	✅	✅

---

es2019

Android (RN version)	0.60.x	0.61.x	0.62.x	0.63.x	0.64.x	0.65.x
Array.prototype.flat (es2019.array)	✅	✅	✅	✅	✅	✅
Array.prototype.flatMap (es2019.array)	✅	✅	✅	✅	✅	✅
Object.fromEntries (es2019.object)	✅	✅	✅	✅	✅	✅
String.prototype.trimEnd (es2019.string)	✅	✅	✅	✅	✅	✅
String.prototype.trimStart (es2019.string)	✅	✅	✅	✅	✅	✅
String.prototype.trimLeft (es2019.string)	✅	✅	✅	✅	✅	✅
String.prototype.trimRight (es2019.string)	✅	✅	✅	✅	✅	✅
Symbol.prototype.description (es2019.symbol)	✅	✅	✅	✅	✅	✅

iOS version	11.0	11.4	12.0	12.4	13.0	14.4
Array.prototype.flat (es2019.array)	❌	❌	✅	✅	✅	✅
Array.prototype.flatMap (es2019.array)	❌	❌	✅	✅	✅	✅
Object.fromEntries (es2019.object)	❌	❌	❌	✅	✅	✅
String.prototype.trimEnd (es2019.string)	❌	❌	✅	✅	✅	✅
String.prototype.trimStart (es2019.string)	❌	❌	✅	✅	✅	✅
String.prototype.trimLeft (es2019.string)	✅	✅	✅	✅	✅	✅
String.prototype.trimRight (es2019.string)	✅	✅	✅	✅	✅	✅
Symbol.prototype.description (es2019.symbol)	❌	❌	✅	✅	✅	✅

---

es2018

Android (RN version)	0.60.x	0.61.x	0.62.x	0.63.x	0.64.x	0.65.x
async function* () { ... } (es2018.asyncgenerator)	❌	❌	❌	❌	❌	❌
for await (let value of range) { ... } (es2018.asynciterable)	❌	❌	❌	❌	❌	❌
Symbol.asyncIterator (es2018.asynciterable)	✅	✅	✅	✅	✅	✅
Intl.PluralRules (es2018.intl)	❌	❌	❌	❌	❌	❌
RegExp.dotAll (es2018.regexp)	✅	✅	✅	✅	✅	✅
Promise.prototype.finally (es2018.promise)	✅	✅	✅	✅	✅	✅

iOS version	11.0	11.4	12.0	12.4	13.0	14.4
async function* () { ... } (es2018.asyncgenerator)	❌	❌	❌	❌	❌	❌
for await (let value of range) { ... } (es2018.asynciterable)	❌	❌	❌	❌	❌	❌
Symbol.asyncIterator (es2018.asynciterable)	❌	✅	✅	✅	✅	✅
Intl.PluralRules (es2018.intl)	❌	❌	❌	❌	✅	✅
RegExp.dotAll (es2018.regexp)	❌	✅	✅	✅	✅	✅
Promise.prototype.finally (es2018.promise)	✅	✅	✅	✅	✅	✅

---

es2017

Android (RN version)	0.60.x	0.61.x	0.62.x	0.63.x	0.64.x	0.65.x
SharedArrayBuffer (es2017.sharedmemory)	❌	❌	❌	❌	❌	❌
Atomics (es2017.typedarrays)	❌	❌	❌	❌	❌	❌
Uint8Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Uint8ClampedArray (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Int16Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Uint16Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Int32Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Uint32Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Float32Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Float64Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Int8Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Intl.DateTimeFormat.prototype.formatToParts(date) (es2017.intl)	❌	❌	❌	❌	❌	❌
Object.getOwnPropertyDescriptors(obj) (es2017.object)	✅	✅	✅	✅	✅	✅
Object.values(obj) (es2017.object)	✅	✅	✅	✅	✅	✅
Object.entries(obj) (es2017.object)	✅	✅	✅	✅	✅	✅
String.prototype.padEnd (es2017.string)	✅	✅	✅	✅	✅	✅
String.prototype.padStart (es2017.string)	✅	✅	✅	✅	✅	✅

iOS version	11.0	11.4	12.0	12.4	13.0	14.4
SharedArrayBuffer (es2017.sharedmemory)	✅	❌	❌	❌	❌	❌
Atomics (es2017.typedarrays)	✅	❌	❌	❌	❌	❌
Uint8Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Uint8ClampedArray (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Int16Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Uint16Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Int32Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Uint32Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Float32Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Float64Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Int8Array (es2017.typedarrays)	✅	✅	✅	✅	✅	✅
Intl.DateTimeFormat.prototype.formatToParts(date) (es2017.intl)	❌	❌	❌	❌	✅	❌
Object.getOwnPropertyDescriptors(obj) (es2017.object)	✅	✅	✅	✅	✅	✅
Object.values(obj) (es2017.object)	✅	✅	✅	✅	✅	✅
Object.entries(obj) (es2017.object)	✅	✅	✅	✅	✅	✅
String.prototype.padEnd (es2017.string)	✅	✅	✅	✅	✅	✅
String.prototype.padStart (es2017.string)	✅	✅	✅	✅	✅	✅

---

es2016

Android (RN version)	0.60.x	0.61.x	0.62.x	0.63.x	0.64.x	0.65.x
Array.prototype.includes (es2016.array)	✅	✅	✅	✅	✅	✅

iOS version	11.0	11.4	12.0	12.4	13.0	14.4
Array.prototype.includes (es2016.array)	✅	✅	✅	✅	✅	✅

---

es2015

Android (RN version)	0.60.x	0.61.x	0.62.x	0.63.x	0.64.x	0.65.x
Symbol (es2015.symbol)	✅	✅	✅	✅	✅	✅
Reflect (es2015.reflect)	✅	✅	✅	✅	✅	✅
Proxy (es2015.proxy)	✅	✅	✅	✅	✅	✅
Promise (es2015.promise)	✅	✅	✅	✅	✅	✅
Map (es2015.collection)	✅	✅	✅	✅	✅	✅
Set (es2015.collection)	✅	✅	✅	✅	✅	✅
function* (){ ... } (es2015.generator)	✅	✅	✅	✅	✅	✅
Symbol.iterator (es2015.iterable)	✅	✅	✅	✅	✅	✅

iOS version	11.0	11.4	12.0	12.4	13.0	14.4
Symbol (es2015.symbol)	✅	✅	✅	✅	✅	✅
Reflect (es2015.reflect)	✅	✅	✅	✅	✅	✅
Proxy (es2015.proxy)	✅	✅	✅	✅	✅	✅
Promise (es2015.promise)	✅	✅	✅	✅	✅	✅
Map (es2015.collection)	✅	✅	✅	✅	✅	✅
Set (es2015.collection)	✅	✅	✅	✅	✅	✅
function* (){ ... } (es2015.generator)	✅	✅	✅	✅	✅	✅
Symbol.iterator (es2015.iterable)	✅	✅	✅	✅	✅	✅