You can use [**js-yaml**][1], which seems to be the most widely used / adopted, and also is officially recommended by [**yaml.org**][2]


```bash
npm i js-yaml
```

Then you can read in the json file, parse with `safeLoad`, and then serialize with `safeDump` like this:

```
const { promises: fs } = require("fs")
const yaml = require('js-yaml');

(async function main() {

    try {

        let configJson = await fs.readFile("./config.json", "utf-8")
        let doc = yaml.safeLoad(configJson)
        let configYaml = yaml.safeDump(doc)
        await fs.writeFile("./config.yaml", configYaml, "utf-8")


    } catch (error) {
        console.log(error)
    }

})()
```

### Further Reading

* [JavaScript YAML Parser][5]
* [How to convert JSON to YAML in javascript][3]
* [Convert yaml to json using javascript][4]




### NPM Libraries

* [nodeca/**js-yaml**][6] ([npm][7] - 5,700 ⭐s
* [jeremyfa/**yaml.js**][8] ([npm][9]) - 796 ⭐s
* [eemeli/**yaml**][10] ([npm][11]) - 298 ⭐s
* [coolaj86/**json2yaml**][12] ([npm][13]) - 69 ⭐s



[1]: https://www.npmjs.com/package/js-yaml
[2]: https://yaml.org/
[3]: https://stackoverflow.com/q/38781929/1366033
[4]: https://stackoverflow.com/q/36973736/1366033
[5]: https://stackoverflow.com/q/4335804/1366033
[6]: https://github.com/nodeca/js-yaml
[7]: https://www.npmjs.com/package/js-yaml
[8]: https://github.com/jeremyfa/yaml.js
[9]: https://www.npmjs.com/package/yamljs
[10]: https://github.com/eemeli/yaml
[11]: https://www.npmjs.com/package/yaml
[12]: https://github.com/coolaj86/json2yaml
[13]: https://www.npmjs.com/package/json2yaml

Using gulp/node, how can I convert this JSON file into a YML file?

Starting file: **`config.json`**

```json
{
  ":hello_world": "Test",
  ":foo_bar": [
    "One.js",
    "Two.txt",
  ]
}
```

Desired output: **`config.yml`**

```yaml
:hello_world: Test 
:foo_bar:
- One.js
- Two.txt
```


Convert json to yml with Gulp/Node

Save yourself the extra dependency with just 10 lines of native node functions

Add the following `copyDir` function:

```js
const { promises: fs } = require("fs")
const path = require("path")

async function copyDir(src, dest) {
 await fs.mkdir(dest, { recursive: true });
 let entries = await fs.readdir(src, { withFileTypes: true });

 for (let entry of entries) {
 let srcPath = path.join(src, entry.name);
 let destPath = path.join(dest, entry.name);

 entry.isDirectory() ?
 await copyDir(srcPath, destPath) :
 await fs.copyFile(srcPath, destPath);
 }
}
```

And then use like this:

```js
copyDir("./inputFolder", "./outputFolder")
```

### Further Reading

* [Copy folder recursively in node.js][4]
* [`fsPromises.copyFile`][1] (added in `v10.11.0`)
* [`fsPromises.readdir`][2] (added in `v10.0`)
* [`fsPromises.mkdir`][3] (added in `v10.0`)



[1]: https://nodejs.org/api/fs.html#fs_fspromises_copyfile_src_dest_mode
[2]: https://nodejs.org/api/fs.html#fs_fspromises_readdir_path_options
[3]: https://nodejs.org/api/fs.html#fs_fspromises_mkdir_path_options
[4]: https://stackoverflow.com/q/13786160/1366033

I am trying to copy a folder using Node `fs` module. I am familiar with `readFileSync()` and `writeFileSync()` methods but I am wondering what method I should use to copy a specified folder? 