Validate related fields in a cue schema?

[cbrgm]

hey, I’m trying my hand at a cue schema to validate a configuration.

{
 foo: "something" 
 bar: "somethingelse"
}

is it possible to define dependencies between fields?

AC:

• The validation should fail (exit code 1 / error) if either only foo or only bar is set.
• It should return exit code 0 / ok if either neither or both have been set.
• In other words: XOR with foo and bar as inputs

Does anyone have an example?

[verdverm]

You can use a disjunction like this #XOR: {} | {a: _, b: _}, however care has to be taken with fields and values generally.

https://cuelang.org/play/?id=weHb_EEW-N3#cue@export@yaml (note how I had to explicitly close the empty struct value)

[cbrgm]

Awesome! That's a good example! Thanks @verdverm

[myitcv]

Related are proposals #822 and #943, specifically numexist, which would handle the edge case that @verdverm flags above.