Feature request: treat absent values for dataclasses as default

Suppose we have a config like this:

some_key {
      importantProperty = some_value
}

and trying to read data class by some_key:

data class SomeKeyConfig(
    val importantProperty: String,
    val minorProperty: Int = 500
)

val config = Config.extract<SomeKeyConfig>("some_key")

Current behavior is IllegalArgumentException. So, one should mark minorProperty as nullable and provide custom getter. It would be nice to avoid that and simply get a data class with default values where needed.

[ov7a]

Looks good for my use-case. Looking at code - isn’t there a possible caveat with null values? HOCON allows to use null value. There may be a problem with (may be you should write a test for it)

key = {
    age = 10
    name = null
}

data class Person(val age:Int, val name: String? = "Sir Null")

From this config, Person(10, null) is expected.

[mmorihiro]

Fixed in 263a89a494e3a7101517c30afbc1c39a9acf53fe