Ordering of various JSONSchema validation constraints changed in generated OpenAPI spec

[adriansuarez]

This was observed on the upgrade from 2.2.30 to 2.2.34.

The following validation constraints now appear at the end of the generated JSONSchemas:

• default
• enum
• items

I suspect that the OpenAPI object that the spec is generated from internally has a LinkedHashMap for each object node to preserve the ordering that properties were added in, because I have my own post-processor that adds and updates various properties and I have always observed that the properties added by the post-processor appear last.
But the constraints above now appear last.

This is problematic because I have a test in CI that checks that the OpenAPI spec that is checked in does not diverge from what would be generated from the code.
I can update the checked in spec based on what Swagger generates with version 2.2.34, but I want to confirm that the new ordering is stable.

I also find it weird for standard validation constraints like default, enum, and items to appear after vendor-specific extensions prefixed with x-.

[daniel-kmiecik]

@adriansuarez thank you for the report! We'll try to review this issue and get back to you as soon as possible.

[adriansuarez]

I adjusted the ordering to be consistent with what Swagger seems to generate now, and just saw our CI build fail due to a random change in ordering of the enum constraint. So the new ordering does not seem stable.

This is a problem for us because it affects our ability to detect API changes in CI.

[adriansuarez]

Actually, it looks like the issue is due to a regression in jackson-databind between 1.18.x and 1.19, which was fixed in 1.19.2.

I suspect it is this issue: FasterXML/jackson-databind#5215

Feel free to close this.

[daniel-kmiecik]

We plan to release swagger-core with new jackson version under this PR #4943
@adriansuarez thank you for support!