Jackson JsonIgnore does not work in Kotlin

[VSMent]

Trying to hide DTO id field and assign JSON id field to DTO cityId

build.gradle (there are some spring related which are omitted here)

//plugins 
    id 'org.jetbrains.kotlin.jvm' version '1.3.70'
    id "org.jetbrains.kotlin.plugin.jpa" version "1.3.70"
    id "org.jetbrains.kotlin.plugin.noarg" version "1.3.70"
    id "org.jetbrains.kotlin.plugin.spring" version "1.3.70"
    id "org.jetbrains.kotlin.plugin.allopen" version "1.3.70"

// dependencies
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
    implementation "org.jetbrains.kotlin:kotlin-reflect"
    implementation "com.fasterxml.jackson.module:jackson-module-kotlin:2.10.2"

TestDto.kt

import com.fasterxml.jackson.annotation.JsonIgnore
import com.fasterxml.jackson.annotation.JsonIgnoreProperties
import com.fasterxml.jackson.annotation.JsonProperty

@JsonIgnoreProperties(ignoreUnknown = true)
data class TestDto(
        @JsonIgnore
        var id: Long? = null,
        var cityId: Int? = null
) {
    @JsonProperty("id")
    private fun unpackId(idObj: Int?) {
        cityId = idObj
    }
}

Test case that fails

    @Test
    fun createTestDto() {
        val dto:TestDto = jacksonObjectMapper().readValue("""{"id":12345}""")
        println(dto)
        assertThat(dto)
                .isNotNull
                .extracting("id").isEqualTo(null)
                .extracting("cityId").isEqualTo(12345)
    }

DTO Object is TestDto(id=12345, cityId=null) instead of TestDto(id=null, cityId=12345)

There was similar issue in FasterXML/jackson-module-kotlin/#124 that is present here #2001, but it should have been resolved till v2.10.2 by #2002

I have opened Stack Overflow question with actual code I am working on, but It seems to be module related issue.

[cowtowncoder]

Please file these issues under jackson-module-kotlin in future, unless they can be reproduced with just databind. I will transfer this now.

[VSMent]

@cowtowncoder ok. I was not really sure which module it belongs.

[hiddewie]

I added the test case as given in this issue locally, but it passes and the output seems correct.

See #387

[dinomite]

Fixed by #388 in 2.12