consider the following pyyaml code (try yourself):

import yaml

print yaml.dump(
  {
    "foo": [1, 2, 3]
  },
  default_flow_style=False
)

which outputs

foo:
- 1
- 2
- 3

and the comparable js-yaml counterpart (try yourself):

const yaml = require("js-yaml");

console.log(
  yaml.safeDump({
    foo: [1, 2, 3]
  })
);

which outputs

foo:
  - 1
  - 2
  - 3

You can see that pyyaml doesn't add spaces to lists (because - counts as indention). I know both are valid, but it would be great if we could a similar output as pyyaml (especially as this project started as some kind of fork)?

Changing this line to

writeBlockSequence(state, level - 1, state.dump, compact);

changes the behaviour so it should be possible to add a configuration setting to allow both behaviours.