From 9ff0294c48f2ce81e95ce30219e19c6db8013327 Mon Sep 17 00:00:00 2001
From: Nicklas Lundin <nicklasl@spotify.com>
Date: Tue, 7 Nov 2023 15:46:23 +0100
Subject: [PATCH] refactor: make targeting key immutable and update mutating
 functions

Signed-off-by: Nicklas Lundin <nicklasl@spotify.com>
---
 .../java/dev/openfeature/sdk/EvaluationContext.kt  |  2 +-
 .../java/dev/openfeature/sdk/ImmutableContext.kt   | 14 +++++++++-----
 .../java/dev/openfeature/sdk/EvalContextTests.kt   |  8 +++++---
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/OpenFeature/src/main/java/dev/openfeature/sdk/EvaluationContext.kt b/OpenFeature/src/main/java/dev/openfeature/sdk/EvaluationContext.kt
index 3141278d..5ac86e6a 100644
--- a/OpenFeature/src/main/java/dev/openfeature/sdk/EvaluationContext.kt
+++ b/OpenFeature/src/main/java/dev/openfeature/sdk/EvaluationContext.kt
@@ -2,7 +2,7 @@ package dev.openfeature.sdk
 
 interface EvaluationContext : Structure {
     fun getTargetingKey(): String
-    fun setTargetingKey(targetingKey: String)
+    fun withTargetingKey(targetingKey: String): EvaluationContext
 
     // Make sure these are implemented for correct object comparisons
     override fun hashCode(): Int
diff --git a/OpenFeature/src/main/java/dev/openfeature/sdk/ImmutableContext.kt b/OpenFeature/src/main/java/dev/openfeature/sdk/ImmutableContext.kt
index a0bd19d8..d60a4ad1 100644
--- a/OpenFeature/src/main/java/dev/openfeature/sdk/ImmutableContext.kt
+++ b/OpenFeature/src/main/java/dev/openfeature/sdk/ImmutableContext.kt
@@ -1,15 +1,19 @@
 package dev.openfeature.sdk
 
-class ImmutableContext
-(private var targetingKey: String = "", attributes: Map<String, Value> = mapOf()) : EvaluationContext {
+class ImmutableContext(
+    private val targetingKey: String = "",
+    attributes: Map<String, Value> = mapOf()
+) : EvaluationContext {
     private val structure: ImmutableStructure = ImmutableStructure(attributes)
     override fun getTargetingKey(): String {
         return targetingKey
     }
 
-    override fun setTargetingKey(targetingKey: String) {
-        this.targetingKey = targetingKey
-    }
+    override fun withTargetingKey(targetingKey: String): ImmutableContext =
+        ImmutableContext(
+            targetingKey = targetingKey,
+            attributes = this.structure.asMap()
+        )
 
     override fun keySet(): Set<String> {
         return structure.keySet()
diff --git a/OpenFeature/src/test/java/dev/openfeature/sdk/EvalContextTests.kt b/OpenFeature/src/test/java/dev/openfeature/sdk/EvalContextTests.kt
index 7fcc6220..3d1170ab 100644
--- a/OpenFeature/src/test/java/dev/openfeature/sdk/EvalContextTests.kt
+++ b/OpenFeature/src/test/java/dev/openfeature/sdk/EvalContextTests.kt
@@ -7,10 +7,12 @@ import java.util.Date
 class EvalContextTests {
 
     @Test
-    fun testContextStoresTargetingKey() {
+    fun testContextIsImmutableButStoresTargetingKey() {
         val ctx = ImmutableContext()
-        ctx.setTargetingKey("test")
-        Assert.assertEquals("test", ctx.getTargetingKey())
+        Assert.assertEquals("", ctx.getTargetingKey())
+
+        val newCtx = ctx.withTargetingKey("test")
+        Assert.assertEquals("test", newCtx.getTargetingKey())
     }
 
     @Test