v2 custom tags: outdated doc and/or broken types

[3bl3gamer]

Describe the bug
In the Writing Custom Tags there is an example:

  stringify(item, ctx, onComment, onChompKeep) {
    ...
    return stringifyString({ value: key }, ctx, onComment, onChompKeep)
  }

It worked in v1.10 but in v2.1 it returns type error:

Argument of type '{ value: string; }' is not assignable to parameter of type 'Scalar<unknown>'.
  Type '{ value: string; }' is missing the following properties from type 'Scalar<unknown>': toJSON, clone, [NODE_TYPE]

To Reproduce

Create custom tag with

  stringify(item, ctx, onComment, onChompKeep) {
    return stringifyString({ value: 'test' }, ctx, onComment, onChompKeep)
  }

Expected behaviour

No error.

Versions:

• Environment: Node: 19.1.0
• yaml: yaml: 2.1.3

[eemeli]

Thank you for reporting this! The argument's type was indeed a bit too strict. This wasn't caught by the tests for custom types, as they are (still) JS rather than TS.

I've also made the examples in the docs a little bit more robust.