Empty Multiline Array Is Having an Empty Line and Whitespace Added Before It

[pjkaufman]

Describe the bug
Thanks for creating this YAML parser. I have been working on using it in one of my projects and I have hit a weird scenario. It seems that in some cases, empty multi-line arrays are having their empty entry moved down a line and having its indentation space added on the line it was on. I am not sure if this YAML is considered correct under the YAML spec in use, so please let me know if the YAML is incorrect/out of spec.

To Reproduce

parseDocument then toString the following YAML:

FFF:
  - 

It seems to result in:

---
FFF:
  
  - 
---

This seems wrong to me, but maybe that is what the spec dictates should happen.

Expected behaviour

I expect the output to be as close to, if not the same as, the input as is possible:

FFF:
  - 

Versions (please complete the following information):

• Environment: Node v18.0.0
• yaml: 2.6.0

Additional context
I am not 100% sure on how nesting levels would affect this or if it would be fine to try to investigate the root cause of the issue. But I would be happy to take a stab at it if you are fine with that.

[eemeli]

Was able to replicate this; this is happening because a newline after a - sequence indicator is setting spaceBefore on the node, and when stringifying that's getting serialised before the - indicator.

Decided to fix this by ignoring newlines after the - for spaceBefore consideration.

[pjkaufman]

Thanks for the quick turn around on this as well as creating and maintaining this library!