Gson -> Moshi name snafu detector

thing.kt

@Test
fun verifySerializedNameMatchesJsonName() {
  // Reflections library
  Reflections("com.foobar").getTypesAnnotatedWith(JsonClass::class.java)
      .flatMap { clz ->
        // FieldUtils is in Apache Commons
        FieldUtils.getAllFieldsList(clz).filter { !Modifier.isStatic(it.modifiers) }
      }
      .forEach { field ->
        val serializedNameAnnotation = field.declaredAnnotations.find { it is SerializedName } as? SerializedName
        val jsonAnnotation = field.declaredAnnotations.find { it is Json } as? Json

        if (serializedNameAnnotation != null) {
          val serializedName = serializedNameAnnotation.value
          val jsonName = jsonAnnotation?.name ?: field.name // The field's name is the implicit name in Moshi

          if (serializedName != jsonName) {
            if (jsonAnnotation == null) {
              fail("$field is annotated with a custom @SerializedName but not @Json")
            }
            else {
              fail("$field @SerializedName and @Json have different names")
            }
          }
        }
      }
}