zed and file descriptors lead to incosistent behaviour

[bracki]

Expected behaviour

zed schema read > my_schema.txt
# edit the schema ...
zed schema write my_schema.txt

Actual behaviour

zed schema write my_schema.txt
{"level":"fatal","error":"rpc error: code = InvalidArgument desc = error parsing schema: parse error in `schema`, line 1, column 1: Unexpected token at root level: TokenTypeLeftBrace","time":"2021-10-28T10:36:37+02:00","message":"failed to write schema"}

This is because whenever zed detects a fd it will switch to JSON/pretty mode. This makes scripting things hard.

Possible solution

Either make formats explicit and don't do autodetection or be compatible when piping/reading into zed.

[jzelinskie]

Yep, we've had this discussion before that this behavior is undocumented and unintuitive.
Not all outputs make sense as JSON, either.
I think we can drop this behavior for now.