Not fully consistent ordering in spring-configuration-metadata.json

Current comparator implementation produces not consistent order for special case, when a codebase contains multiple classes that shares same “namespace” and (optionally) same properties.

Consider this example:

package com.example;

@ConfigurationProperties("app.section")
public class Foo {
  private int val;
}

@ConfigurationProperties("app.section")
public class Bar {
  private boolean flag;
  private int val;
}

As both classes share same section (and it works in runtime just fine), this leads to multiple outcomes in groups sections, as well as in properties section:

  "groups": [
    {
      "name": "app.section",                          // order can be swapped!
      "type": "com.example.Foo",
      "sourceType": "com.example.Foo"
    },
    {
      "name": "app.section",
      "type": "com.example.Bar",
      "sourceType": "com.example.Bar""
    }
  ],

Same is applied for val in this exampe, as name is same, but type/sourceType is different.

I understand that this is extreme example, but it is valid in terms of spring support, so I think that adding sort stage for type can solve this problem:

private final Comparator<ItemMetadata> propertyComparator = Comparator.<ItemMetadata, Boolean>comparing(ItemMetadata::isDeprecated)
                .thenComparing(ItemMetadata::getName)
                .thenComparing(ItemMetadata::getType);
private final Comparator<ItemMetadata> groupComparator = Comparator.<ItemMetadata, String>comparing(ItemMetadata::getName).thenComparing(ItemMetadata::getType);

[zeldigas]

Deal. I’m going to work on PR this weekend.

[zeldigas]

OK, looks like I need to get familiar with the process better, sorry.