Case classes with option types don't follow serialization configuration

[fasterxml]

Case classes with option types don't follow serialization configuration

[jsw]

This seems to be broken again in 2.7.4 and 2.7.5.

I setup my ObjectMapper using

val mapper = new ObjectMapper with ScalaObjectMapper
mapper.registerModule(DefaultScalaModule)
mapper.registerModule(new JavaTimeModule)
mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL)
mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
mapper.configure(DeserializationFeature.READ_DATE_TIMESTAMPS_AS_NANOSECONDS, false)

and the following test fails

val json = mapper.writeValueAsString(C(None, None))
assert(json === "{}")

[info] - should not serialize null fields *** FAILED ***
[info]   "{["a":null,"b":null]}" did not equal "{[]}" (JacksonUtilTest.scala:27)

[christophercurrie]

Thanks for the bug report, I'll take a look at why the works for normal classes and see what needs to be added to the case class logic.

[christophercurrie]

While I haven't yet worked out a way to support this using JsonInclude.Include.NON_NULL (which makes the most logical sense, but doesn't appear to have a hook in JsonSerializer, I have added support in OptionSerializer to recognize and honor JsonInclude.Include.NON_EMPTY to achieve the same goal.

[christophercurrie]

Reopening, as I realize now that this issue is slightly different than #9.

[christophercurrie]

I added what I think is a functionally equivalent pair of tests to CaseClassSerializerTest and was not able to reproduce the problem. If you can, please retest your use case with the latest code and reopen if you continue to have issues.

[christophercurrie]

Well it looks like my tests were bad. Reopening as I've fixed the tests and the problem still exists.

[christophercurrie]

Ok, filing in some more information so I don't forget it.

• The non-case class isn't succeeding because it's working properly, it's succeeding because the Scala module doesn't currently recognized the property. If I add @JsonProperty annotation to TestObject3, the test fails.
• Getting NOT_NULL recognized requires that Jackson recognize that it's possible for a non-null value in the JVM to be serialized as JSON "null". Jackson doesn't currently have a hook for this, but I've got an idea for an approach that might work by replacing BeanPropertyWriter with a new version that recognizes "null-like" values.

I should have a fix for this shortly.

[leons727]

With jackson 2.1.0 and jackson-module-scala 2.1.1-SNAPSHOT:

case class Foo(val a: String, val b: Option[Int] = None)

@RunWith(classOf[BlockJUnit4ClassRunner])
class TryJSON {

@test
def testNulls() {
val m = new ObjectMapper()
m.registerModule(new DefaultScalaModule())
m.setSerializationInclusion(JsonInclude.Include.NON_NULL)
println(m.writeValueAsString(new Foo(null, None)))
}
}

Prints:

{"a":null,"b":null}

Am I missing something?

[christophercurrie]

Nope, my tests are bad, #45 also reported this. Will fix ASAP and issue a 2.1.1 for it.

[christophercurrie]

This issue should be resolved in 2.1.1, just released.

[leons727]

Yes, works for me correctly now. Thanks for the quick turnaround!

[devshorts]

Seems still broken in 2.8.3 as well

[ptagr]

is there a workaround for this ?

[jsw]

Use JsonInclude.Include.NON_ABSENT. See issue 280