Fix immutability

Signed-off-by: Bence Hornák <[email protected]>

Author: bencehornak

kotlin-sdk/build.gradle.kts

@@ -47,6 +47,7 @@ kotlin {
     sourceSets {
         commonMain.dependencies {
             implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.7.3")
+            implementation("org.jetbrains.kotlinx:kotlinx-collections-immutable:0.4.0")
         }
         commonTest.dependencies {
             implementation("org.jetbrains.kotlin:kotlin-test:2.1.21")

kotlin-sdk/src/commonMain/kotlin/dev/openfeature/kotlin/sdk/ImmutableStructure.kt

@@ -1,9 +1,11 @@
 package dev.openfeature.kotlin.sdk
 
+import kotlinx.collections.immutable.toImmutableList
+import kotlinx.collections.immutable.toImmutableMap
 import kotlin.time.ExperimentalTime
 
 class ImmutableStructure(attributes: Map<String, Value> = mapOf()) : Structure {
-    private val attributes: Map<String, Value> = attributes.toMap()
+    private val attributes: Map<String, Value> = attributes.toImmutableMap()
 
     constructor(vararg pairs: Pair<String, Value>) : this(pairs.toMap())
 
@@ -16,18 +18,18 @@ class ImmutableStructure(attributes: Map<String, Value> = mapOf()) : Structure {
     }
 
     override fun asMap(): Map<String, Value> {
-        return attributes.toMap()
+        return attributes
     }
 
     override fun asObjectMap(): Map<String, Any?> {
-        return attributes.mapValues { convertValue(it.value) }.toMap()
+        return attributes.mapValues { convertValue(it.value) }.toImmutableMap()
     }
 
     @OptIn(ExperimentalTime::class)
     private fun convertValue(value: Value): Any? {
         return when (value) {
-            is Value.List -> value.list.map { t -> convertValue(t) }.toList()
-            is Value.Structure -> value.structure.mapValues { t -> convertValue(t.value) }.toMap()
+            is Value.List -> value.list.map { t -> convertValue(t) }.toImmutableList()
+            is Value.Structure -> value.structure.mapValues { t -> convertValue(t.value) }.toImmutableMap()
             is Value.Null -> return null
             is Value.String -> value.asString()
             is Value.Boolean -> value.asBoolean()