Babel plugin to convert Flow into TypeScript

Usage no npm install needed!

<script type="module">
  import voxyluBabelPluginFlowToTypescript from 'https://cdn.skypack.dev/@voxylu/babel-plugin-flow-to-typescript';



Babel plugin to convert Flow code into TypeScript

How to use

$ yarn add @babel/cli @babel/core
$ yarn add @voxylu/babel-plugin-flow-to-typescript

# you must use babel@^7.x.x
$ yarn babel --version
7.2.3 (@babel/core 7.2.2)

$ yarn babel --plugins @voxylu/babel-plugin-flow-to-typescript ${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 (x1: A, x2: 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]
typeof operator typeof foo typeof foo
JSX - -
Tuple type [number, string] [number, string]
Exact type {|a: T|} {a: T}
Type alias type A = string type A = string