JsonJacksonApprovals doesn't work with Java 8 time types and the JSON output is not deterministic

[cgt]

JsonJacksonApprovals creates the Jackson ObjectMapper by calling new ObjectMapper(). This ObjectMapper will not support Java 8 time types because support for that comes in a separate module (jackson-datatype-jsr310). Whenever I use approvals, I end up having to make my own copy of JsonJacksonApprovals where I change the asJson method to the following:

public static String asJson(Object o, Function1<ObjectMapper, ObjectMapper> objectMapperBuilder) {
    try {
        final var mapper = JsonMapper.builder()
            .findAndAddModules()
            .enable(SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS)
            .enable(MapperFeature.SORT_PROPERTIES_ALPHABETICALLY)
            .build();
        ObjectMapper objectMapper = objectMapperBuilder.call(mapper);
        return objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(o);
    } catch (JsonProcessingException e) {
        throw ObjectUtils.throwAsError(e);
    }
}

findAndAddModules automatically finds the Jackson Java 8 time module if available. Additionally, I enable two settings for ensuring that the output is deterministic. Without those settings, I've seen the fields change order in the document, which spuriously causes the approvals to fail.

Is there any particular reason why all these settings are not enabled by default? It would be great if I didn't have to copy and modify JsonJacksonApprovals every time I use it.

[LarsEckart]

Thanks for reaching out and raising this issue, I wasn't aware of the built-in sorting feature for example.

We get together next Monday again and look into this so that you can get an answer and perhaps even a new release with this feature.

[ScottBob]

One thing I might suggest is to use this approach instead of overriding the method:

    JsonJacksonApprovals.verifyAsJson(o, om -> om.findAndRegisterModules()
        .enable(SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS)
        .enable(MapperFeature.SORT_PROPERTIES_ALPHABETICALLY)
    );

If you want these settings regularly, you can wrap this in a function, and it should keep things succinct.

[LarsEckart]

In release 26.0.0 we have changed the default behaviour so that it will automatically find and register modules, and it will order map keys alphabetically. We did not pull in the sorting of properties, because it would break backwards compatibility.

Scott's suggestion is the preferred way we see to still enable it.