In my shared code I have this and would a contract...

# multiplatform

[James Black]

In my shared code I have this and would a contract make sense here to so I don't have to force unwrap or use the null checks where I call the add function? I am trying to understand where the contract keyword makes sense.

fun addClothingToClothingWeather(clothing:ClothingTypes) {
        if(clothingWeatherData == null) clothingWeatherData = ClothingWeatherModel()
        clothingWeatherData!!.clothing?.toMutableList()?.add(clothing)
    }

@Serializable
data class ClothingWeatherModel(val clothing:List<ClothingTypes>? = emptyList(), val temperature:MainTemperature? = null, val situation:Situations? = null)

[Rick Clephas]

I don’t think a contract makes sense here. Why? Because you are working with mutable data.
Some concurrent could actually modify your clothingWeatherData variable and possibly set it to null. So you can’t really guarantee that it isn’t null.

FYI toMutableList actually makes a copy of your list, so the added clothing won’t be part of the original list in the ClothingWeatherModel.

Something like the following would work:

@Serializable
data class ClothingWeatherModel(
    val clothing:List<ClothingTypes>? = emptyList(),
    val temperature:MainTemperature? = null,
    val situation:Situations? = null
)

var clothingWeatherData: ClothingWeatherModel? = null

fun addClothingToClothingWeather(clothing:ClothingTypes) {
    val data = clothingWeatherData ?: ClothingWeatherModel()
    val list = data.clothing?.toMutableList()?.apply { add(clothing) } ?: listOf(clothing)
    clothingWeatherData = data.copy(clothing = list)
}

[James Black]

Thanks, I figured that out after I posted this that my list wasn't being put into the data class. I also decided to just initialize clothingWeatherData right away so it is always initialized.