babel-plugin-flow-to-typescript
Babel plugin to convert Flow code into TypeScript
How to use
$ yarn global add @babel/cli
$ yarn add @steelbrain/babel-plugin-flow-to-typescript
# you must use babel@^7.x.x
$ babel --version
7.0.0-beta.44 (@babel/core 7.0.0-beta.44)
$ babel --plugins @steelbrain/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 |
|
| Object type | Object |
object |
|
| Mixed type | mixed |
unknown |
|
| 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 | |
| Type alias | type A = string |
type A = string |
|
| Flow Ignore | $FlowFixMe |
any |
|
| Interfaces | interface X { +prop: string } |
interface X { readonly prop: string } |
|
| Optional Members | a?.b |
a == null ? null : a.b == null ? null : a.b |
|
| Declare functions | declare function x(false): true; |
function x(x0: false): true; |