node_updates.kt

@Composable
fun Component(hasDiv: Boolean) {
    // Note that Component does not add anything to tree directly
    // Only calls to emit change "virtual DOM"
    // Here it is called from div -> tag -> emit
    if (hasDiv) {
        div() // <-- adding or removing node here based on parameter, updating tree
    }
}

@Composable
fun Test() {
    // Changing this state results in re-execution of places it used in
    var hasDiv by state { false }
    // For example, state can be changed based on event from user (click)
    button(onClick = { hasDiv = !hasDiv })
    
    // This function will be re-invoked whenever hasDiv changes value
    Component(hasDiv)
}