Override SnakeYAML output ordering for OpenAPI documents

[tjquinno]

Environment Details

• Helidon Version: 1.4.3, 2.x
• Helidon SE or Helidon MP: n/a
• JDK version: n/a
• OS: n/a
• Docker version (if applicable): n/a

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SnakeYAML serializes its output in an indeterminate order. While this is valid according to specs, it is very inconvenient for human readers.

There might be ways of overriding the SnakeYAML ordering. This issue is to track that investigation.

[tjquinno]

This posting has a possible way of accomplishing this. Need to see if it still works and whether adding this amount of code would make sense to resolve the ordering problem.

https://stackoverflow.com/questions/31534014/keep-tags-order-using-snakeyaml

[update] It seems as if the existing SnakeYAML code base has adopted the suggestion in the above post.

[tjquinno]

Tomas and I agree that, when we have seen this, we do not remember the elements within an app or a path (which most directly represents an endpoint) being indeterminate. Tomas is certain he has seen endpoints grouped by app rearranged by app apparently indeterminately.

My quick research into the SnakeYAML code shows the use of ordered maps, not just HashMaps for example, so SnakeYAML seems to preserve property ordering.

There might be something going on inside SmallRye or in how Helidon presents different apps to SmallRye for annotation processing. Still looking.