YAML <-> JSON runs the js-yaml library in either direction from one mode toggle, turning a YAML file into JSON or a JSON value back into YAML. Invalid YAML or JSON gets refused with that parser's own error message. YAML's own coercions, an unquoted yes reading as true or a bare number reading as a number, apply exactly as js-yaml defines them.
Questions
What library does the conversion?
js-yaml, imported lazily inside the run.
What YAML type coercions apply?
Whatever js-yaml itself defines, an unquoted yes becoming true or a bare number becoming a number, not a custom rule this tool adds.
What happens with invalid YAML?
The tool refuses with js-yaml's own parser error message.
What happens with invalid JSON?
The tool refuses with JSON.parse's own error message.
Does it preserve comments?
No, YAML comments are not represented in JSON, so converting to JSON and back loses them.
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