Make addSuperclassConstructorParameter args nullable

[PaulWoitaschek]

I want to add a nullable property to an enum. This doesn't currently work using the format function becuase the arg elements are not declared as nullable.

TypeSpec.enumBuilder("Sample")
  .primaryConstructor(
    FunSpec.constructorBuilder()
      .addParameter(
        ParameterSpec.builder(
          "myNullableString",
          String::class.asTypeName().copy(nullable = true)
        ).build()
      )
      .build()
  )
  .addEnumConstant(
    name = "Rock",
    typeSpec = TypeSpec.anonymousClassBuilder()
      .addSuperclassConstructorParameter("%S", "Hello")
      .build()
  )
  .addEnumConstant(
    name = "Paper",
    typeSpec = TypeSpec.anonymousClassBuilder()
      .addSuperclassConstructorParameter("%S", null) // <-- this doesn't compile
      .addSuperclassConstructorParameter(CodeBlock.of("%S", null)) // <-- workaround
      .build()
  )
  .build()

[Egorand]

Looks like an omission, CodeBlock args are usually nullable. Should be an easy fix.

[JakeWharton]

What is the code you are trying to emit? As far as I can tell, this is working as intended. You either want just "null" for a null literal in the source or "%S", "null" for the string "null".

[PaulWoitaschek]

I want to emit a null when my string is null:

package my.something.t

import com.squareup.kotlinpoet.*

fun main() {
  val builder = TypeSpec.enumBuilder("Sample")
      .primaryConstructor(
          FunSpec.constructorBuilder()
              .addParameter(
                  ParameterSpec.builder(
                      "myNullableString",
                      String::class.asTypeName().copy(nullable = true)
                  ).build()
              )
              .build()
      )

  fun appendEnumConstant(name: String, value: String?) {
    builder.addEnumConstant(
        name = name,
        typeSpec = TypeSpec.anonymousClassBuilder()
            .addSuperclassConstructorParameter("%S", value) // (1)
            .addSuperclassConstructorParameter(CodeBlock.of("%S", value)) // (2)
            .build()
    )

  }
  appendEnumConstant("Rock", "Something")
  appendEnumConstant("Scissor", null)
  println(builder.build())
}

I want the line marked with (1) to compile.

enum class Sample(
  myNullableString: kotlin.String?
) {
  Rock("Something"),

  Scissor(null)
}

[JakeWharton]

Yeah I'm not super enthusiastic about that behavior, and I'm tempted to even classify the existing CodeBlock behavior a bug. Having a null literal produced from %S seems quite odd.