-p yaml and -p json do not behave the same, but --help implies that they do.

[lhmathies]

Describe the bug

Version of yq: 4.35.2

Operating system: windows/

Input Json
"foo"
"bar"

Command
The command you ran:

$ yq eval --help | grep input-format
  -p, --input-format string           [auto|a|yaml|y|props|p|xml|x|tsv|t|csv|c|toml] parse format for input. Note that json is a subset of yaml. (default "auto")
$ echo $'"foo"\n"bar"' | yq -p json -o json
"foo"
"bar"
$ echo $'"foo"\n"bar"' | yq -p auto -o json
"foo"
Error: bad file '-': yaml: line 1: did not find expected <document start>

Expected behavior
-p json is not expected to make a difference, or indeed to be accepted, according to the help text. If you ask me, a sequence of JSON objects should be parsed under -p auto, even without YAML document separators.

Additional context
The difference is of course that -p json does not insist on YAML document separators. This should be documented.

[mikefarah]

This has been updated in the later versions of yq