How do I edit a yaml file and keep new lines?

[KungWaz]

If I want to edit the provided yaml file below and keep the empty new line, for readability, how would I do that?
Currently when I use the parser and then save it back to the same file when I have edited it the new line between the devices and items blocks is removed.

Code:

import { parse } from "yaml";
import fs from "fs";

const path = "./.github/workflows/main.yml";
const file = fs.readFileSync(path);
const yaml = parse(file.toString());

yaml["devices"]["laptop"]["name"] = "asus";

fs.writeFileSync(path, stringify(yaml, { lineWidth: 0 }));

YAML:

devices:
  laptop:
    name: not_set
  desktop:
    name: dell

items:
  keyboard:
    name: not_set
  mouse:
    name: logitech

Result:

devices:
  laptop:
    name: asus
  desktop:
    name: dell
items:
  keyboard:
    name: not_set
  mouse:
    name: logitech

Expected:

devices:
  laptop:
    name: asus
  desktop:
    name: dell

items:
  keyboard:
    name: not_set
  mouse:
    name: logitech

[eemeli]

You'll need to use the Document interface to keep such metadata: https://eemeli.org/yaml/#documents

[KungWaz]

Is there any basic example somewhere to see how to use it? From reading/parsing the file to editing a specific value and then saving it again?

[eemeli]

Most of the examples in the right sidebar of the docs concern themselves with just this sort of manipulation.

[KungWaz]

Thanks for pointing me to the right place in the docs.

This seems to do what I want:

import { parseDocument } from "yaml";
import fs from "fs";

const path = "test.yaml";

const file = fs.readFileSync(path, "utf8");
const yaml = parseDocument(file);

yaml.setIn(["devices", "laptop", "name"], "asus");
yaml.deleteIn(["items", "mouse"]);

fs.writeFileSync(path, yaml.toString(), "utf-8");