babel-plugin-flow2ts

babel-plugin-flow-to-typescript

Babel plugin to convert Flow code into TypeScript

How to use

$ yarn global add @babel/cli 
$ yarn add babel-plugin-flow2ts

# you must use babel@^7.x.x
$ babel --version 
7.0.0-beta.44 (@babel/core 7.0.0-beta.44)

$ babel --plugins babel-plugin-flow2ts ${SRC_FLOW_FILE} -o ${DEST_TS_FILE}

Implementation status

Supported?	Syntax	Flow	TypeScript
❎	Maybe type	let a:?number	let a: number | null | undefined
❎	Void type	void	void
❎	Mixed type	mixed	{}
❎	Function type	(A, B) => C	(a: A, b: B) => C
❎	Exact type	{| a: A |}	{ a: A }
❎	Indexers	{ [A]: B }	{ [a: A]: B }
❎	Existential type	Map<*, *>	Map<any, any>
❎	Opaque types	opaque type A = B	type A = B
❎	Variance	interface A { +b: B, -c: C }	interface A { readonly b: B, c: C }
❎	Type parameter bounds	function f<A: string>(a:A){}	function f<A extends string>(a:A){}
❎	Cast	(a: A)	(a as A)
❎	type/typeof import	import type A from 'module'	import A from 'module'
❎	$Keys	$Keys<X>	keyof X
❎	$Values	$Values<X>	X[keyof X]
❎	$ReadOnly	$Readonly<X>	Readonly<X>
❎	$Exact	$Exact<X>	X
❎	$Diff	$Diff<X, Y>	Pick<X, Exclude<keyof X, keyof Y>>
❎	$PropertyType	$PropertyType<T, k>	T[k]
❎	$ElementType	$ElementType<T, k>	T[k]

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