ucarion
commented
3 years ago Hi, thanks for taking the time to report this bug report!
This is indeed a bug. The schema you provided is in fact not a valid JSON Type Definition schema -- the schema at /properties/bar/mapping/foo is of the empty form, but mapping schemas must be of the properties form -- but jtd-codegen should be providing a clear error message to this effect, and certainly shouldn't be panicking.
A bit more details on what schemas can appear inside mappings is covered here: https://jsontypedef.com/docs/jtd-in-5-minutes/
You can only use properties / optionalProperties / additionalProperties in the schemas you put directly in mapping. You can’t use any other kind of schema, otherwise things would become ambiguous.
Admittedly, that language is a bit loose, and I understand how you would think that using no keywords at all would be kosher. The RFC is a bit more explicit: https://tools.ietf.org/html/rfc8927#section-2
; discriminator describes the "discriminator" schema form.
;
; There are additional constraints on this form that cannot be
; expressed in CDDL. Section 2.2.8 describes these additional
; constraints in detail.
discriminator = (
discriminator: tstr,
; Note well: this rule is defined in terms of the "properties"
; CDDL rule, not the "schema" CDDL rule.
mapping: { * tstr => { properties } }
shared,
)But again: jtd-codegen should not be leaving you out to dry like this.
In the immediate term, I suspect you'll have success if you alter your schema to be a valid JTD schema. For instance, just adding "properties": {} to foo would make your schema valid. This schema seems to work, at least for me:
{
"properties": {
"tag": {
"enum": [
"foo"
]
},
"bar": {
"discriminator": "tag",
"mapping": {
"foo": {
"properties": {}
}
}
}
}
}In the longer term, the jtd-codegen bug here is that the tool should validate a schema's correctness before attempting to generate code from it, and produce an error message rather than generate code (and ultimately crash).
karvus
A minimal example is as follows:
As I understand the spec, this should be a valid Typedef. When I try to run it by
$ RUST_BACKTRACE=full jtd-codegen foo.jtd.json --log-format minimal --typescript-out .I get the following panic and backtrace.
Version is 0.4.0.
I feel that this is a bug.
Cheers
Edit: I tried with the latest release 0.4.1, and the problem remains the same.