Add draft-06 contains support

[Adityakumar37]

Hi @jdesrosiers

I made the required updates for draft-06/07 contains support:

Registered only the draft-06 keyword URI:
https://json-schema.org/keyword/draft-06/contains
(since draft-06 and draft-07 share the same keyword URI)

Added a draft-specific normalization handler at:
src/normalization-handlers/draft-06/contains.js
which implements the simpler draft-06 semantics (at least one matching item, no minContains/maxContains).

Updated the shared error handler (src/error-handlers/contains.js) to treat
draft-06/contains as a special case:

• skips minContains/maxContains processing
• always reports the default range { minContains: 1 }

All tests are passing locally, and lint/type-check are clean.

Please let me know if anything else should be adjusted.

[jdesrosiers]

If this is the best we can do, then it doesn't make sense to use a shared handler. None of the meaningful code is shared, only the boilerplate.

However, I think it can be done in a way that makes sense for it to be shared. In draft-06, there is no minContains/maxContains keywords, so we can be confident that they will never be there. That means it doesn't hurt to check for them. If we just let them be checked regardless of which version of the keyword it is, I'm pretty sure things will just work. That was the entire handler can be the same and the only change needed is the loop to check for both keywor URIs.

[Adityakumar37]

Thanks for the guidance!

1. Removed the draft-06 specific normalization handler
2. Reused the shared contains normalization handler for both URIs
3. Kept only the loop that checks both keyword URIs

[jdesrosiers]

You can't reuse the normalization handler. They produce different values. The draft-06 version only has a string (the schema location). The current version is an object containing the schema location and the min/max constraints.

I noticed that you never enabled the draft-06 and draft-07 tests in the test runner. When you do that, you should see test failures from this bug.

[Adityakumar37]

Thanks understood.

[Adityakumar37]

Hi @jdesrosiers

when I enable the draft-06/07 tests I get this failure:

• Expected: one contains-message error at the array root (#)
• Received: multiple item-level type errors (Expected a number) for every element

So it seems my handler is returning per-item outputs instead of the boolean summary that the current contains error handler expects.

Could you confirm what the correct normalized output should be for draft-06 contains?

Should the draft-06 normalization handler:

• behave exactly like the existing contains handler and return true/false, or
• return item outputs and rely on different error handling?

Once I know the expected structure, I can fix it properly.

Thanks