Nullable types for fields with default values in Kotlin

Currently a schema like

input ColorFilter {
    color: String = "red"
}

generates a Kotlin class like (shortened to the constructor)

public data class ColorFilter(
  @JsonProperty("color")
  public val color: String? = "red"
)

According to the spec

An input field is required if it has a non‐null type and does not have a default value. Otherwise, the input object field is optional.

To my understanding this would allow to generate

public data class ColorFilter(
  @JsonProperty("color")
  public val color: String = "red"
)

as the field will be always set in this case. This would using the generated class a tad easier as it avoids using ?. or !!.

Start by tracing how GraphQL input fields with default values become Kotlin constructor properties; the issue does not name a source file, test, or entry point. Compare the generated nullability with the GraphQL required-field rule, and consider the work done when defaulted fields generate as non-null while other optional fields retain their current behavior.