https://github.com/escaton/flow-comments-codemod

Convert flowtype syntax to valid JS
https://github.com/escaton/flow-comments-codemod

Last synced: 3 months ago
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Convert flowtype syntax to valid JS

• Host: GitHub
• URL: https://github.com/escaton/flow-comments-codemod
• Owner: escaton
• Created: 2019-05-23T13:46:17.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2023-01-03T22:28:56.000Z (about 2 years ago)
• Last Synced: 2024-08-02T07:14:31.361Z (7 months ago)
• Language: TypeScript
• Homepage:
• Size: 1.08 MB
• Stars: 4
• Watchers: 2
• Forks: 1
• Open Issues: 14
• Metadata Files:
  • Readme: README.md

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• awesome-codemods - flow-comments-codemod - Convert flowtype syntax to valid JS. (JavaScript)

README

        
## flow-comments-codemod [![Build Status](https://travis-ci.org/escaton/flow-comments-codemod.svg)](https://travis-ci.org/escaton/flow-comments-codemod)

This codemod converts [Flow](https://flow.org) syntax into valid JS, but keep it [valid Flow](https://flow.org/en/docs/types/comments/).

Such transformation may be useful with gradual migration from Flow to Typescript.

```js

type Arg = { data: number }

function fn(arg: Arg): void {

    console.log(arg)

}

```

```js

/*:: type Arg = { data: number } */

function fn(arg/*: Arg*/)/*: void*/ {

    console.log(arg)

}

```

More examples [here](https://github.com/escaton/flow-comments-codemod/tree/master/src/__testfixtures__)

Compared to [@babel/plugin-transform-flow-comments](https://babeljs.io/docs/en/babel-plugin-transform-flow-comments) this transformation better handles comment line breaks and doesn't touch unchanged code.

### Known issues

In some cases the result may look a bit messy:

```js

var f = (d: any): number);

```

```js

var f = (((d/*: any*/)/*: number*/));

```

so i recommend to apply [Prettier](http://prettier.io/) after transformation.

### Setup & Run

This tool is based on [jscodeshift](https://github.com/facebook/jscodeshift)

```sh

npm install -g jscodeshift

git clone https://github.com/escaton/flow-comments-codemod.git

jscodeshift -t  

```

Use the `-d` option for a dry-run and use `-p` to print the output for

comparison.