feat: In-memory provider, gherkin spec test (#208)

Signed-off-by: Marcin Stepien <marcin.stepien@fluxon.com>

Author: mstepien

kotlin-sdk/api/android/kotlin-sdk.api

@@ -861,3 +861,68 @@ public abstract interface class dev/openfeature/kotlin/sdk/multiprovider/MultiPr
 	public abstract fun evaluate (Ljava/util/List;Ljava/lang/String;Ljava/lang/Object;Ldev/openfeature/kotlin/sdk/EvaluationContext;Lkotlin/jvm/functions/Function4;)Ldev/openfeature/kotlin/sdk/ProviderEvaluation;
 }
 
+public abstract interface class dev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator {
+	public abstract fun evaluate (Ldev/openfeature/kotlin/sdk/providers/memory/Flag;Ldev/openfeature/kotlin/sdk/EvaluationContext;)Ljava/lang/String;
+}
+
+public final class dev/openfeature/kotlin/sdk/providers/memory/Flag {
+	public static final field Companion Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Companion;
+	public fun <init> (Ljava/util/Map;Ljava/lang/String;Ldev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator;Ldev/openfeature/kotlin/sdk/EvaluationMetadata;Z)V
+	public synthetic fun <init> (Ljava/util/Map;Ljava/lang/String;Ldev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator;Ldev/openfeature/kotlin/sdk/EvaluationMetadata;ZILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public final fun component1 ()Ljava/util/Map;
+	public final fun component2 ()Ljava/lang/String;
+	public final fun component3 ()Ldev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator;
+	public final fun component4 ()Ldev/openfeature/kotlin/sdk/EvaluationMetadata;
+	public final fun component5 ()Z
+	public final fun copy (Ljava/util/Map;Ljava/lang/String;Ldev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator;Ldev/openfeature/kotlin/sdk/EvaluationMetadata;Z)Ldev/openfeature/kotlin/sdk/providers/memory/Flag;
+	public static synthetic fun copy$default (Ldev/openfeature/kotlin/sdk/providers/memory/Flag;Ljava/util/Map;Ljava/lang/String;Ldev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator;Ldev/openfeature/kotlin/sdk/EvaluationMetadata;ZILjava/lang/Object;)Ldev/openfeature/kotlin/sdk/providers/memory/Flag;
+	public fun equals (Ljava/lang/Object;)Z
+	public final fun getContextEvaluator ()Ldev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator;
+	public final fun getDefaultVariant ()Ljava/lang/String;
+	public final fun getDisabled ()Z
+	public final fun getFlagMetadata ()Ldev/openfeature/kotlin/sdk/EvaluationMetadata;
+	public final fun getVariants ()Ljava/util/Map;
+	public fun hashCode ()I
+	public fun toString ()Ljava/lang/String;
+}
+
+public final class dev/openfeature/kotlin/sdk/providers/memory/Flag$Builder {
+	public fun <init> ()V
+	public final fun build ()Ldev/openfeature/kotlin/sdk/providers/memory/Flag;
+	public final fun contextEvaluator (Ldev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator;)Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Builder;
+	public final fun defaultVariant (Ljava/lang/String;)Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Builder;
+	public final fun disabled (Z)Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Builder;
+	public final fun flagMetadata (Ldev/openfeature/kotlin/sdk/EvaluationMetadata;)Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Builder;
+	public final fun variant (Ljava/lang/String;Ljava/lang/Object;)Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Builder;
+	public final fun variants (Ljava/util/Map;)Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Builder;
+}
+
+public final class dev/openfeature/kotlin/sdk/providers/memory/Flag$Companion {
+	public final fun builder ()Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Builder;
+}
+
+public final class dev/openfeature/kotlin/sdk/providers/memory/InMemoryProvider : dev/openfeature/kotlin/sdk/FeatureProvider {
+	public fun <init> ()V
+	public fun <init> (Ljava/util/Map;)V
+	public synthetic fun <init> (Ljava/util/Map;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun getBooleanEvaluation (Ljava/lang/String;ZLdev/openfeature/kotlin/sdk/EvaluationContext;)Ldev/openfeature/kotlin/sdk/ProviderEvaluation;
+	public fun getDoubleEvaluation (Ljava/lang/String;DLdev/openfeature/kotlin/sdk/EvaluationContext;)Ldev/openfeature/kotlin/sdk/ProviderEvaluation;
+	public fun getHooks ()Ljava/util/List;
+	public fun getIntegerEvaluation (Ljava/lang/String;ILdev/openfeature/kotlin/sdk/EvaluationContext;)Ldev/openfeature/kotlin/sdk/ProviderEvaluation;
+	public fun getMetadata ()Ldev/openfeature/kotlin/sdk/ProviderMetadata;
+	public fun getObjectEvaluation (Ljava/lang/String;Ldev/openfeature/kotlin/sdk/Value;Ldev/openfeature/kotlin/sdk/EvaluationContext;)Ldev/openfeature/kotlin/sdk/ProviderEvaluation;
+	public fun getStringEvaluation (Ljava/lang/String;Ljava/lang/String;Ldev/openfeature/kotlin/sdk/EvaluationContext;)Ldev/openfeature/kotlin/sdk/ProviderEvaluation;
+	public fun initialize (Ldev/openfeature/kotlin/sdk/EvaluationContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun observe ()Lkotlinx/coroutines/flow/Flow;
+	public fun onContextSet (Ldev/openfeature/kotlin/sdk/EvaluationContext;Ldev/openfeature/kotlin/sdk/EvaluationContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun shutdown ()V
+	public fun track (Ljava/lang/String;Ldev/openfeature/kotlin/sdk/EvaluationContext;Ldev/openfeature/kotlin/sdk/TrackingEventDetails;)V
+	public final fun updateFlags (Ljava/util/Map;)V
+}
+
+public final class dev/openfeature/kotlin/sdk/providers/memory/InMemoryProvider$InMemoryProviderMetadata : dev/openfeature/kotlin/sdk/ProviderMetadata {
+	public fun <init> (Ljava/lang/String;)V
+	public fun getName ()Ljava/lang/String;
+	public fun getOriginalMetadata ()Ljava/util/Map;
+}
+

kotlin-sdk/api/jvm/kotlin-sdk.api

@@ -861,3 +861,68 @@ public abstract interface class dev/openfeature/kotlin/sdk/multiprovider/MultiPr
 	public abstract fun evaluate (Ljava/util/List;Ljava/lang/String;Ljava/lang/Object;Ldev/openfeature/kotlin/sdk/EvaluationContext;Lkotlin/jvm/functions/Function4;)Ldev/openfeature/kotlin/sdk/ProviderEvaluation;
 }
 
+public abstract interface class dev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator {
+	public abstract fun evaluate (Ldev/openfeature/kotlin/sdk/providers/memory/Flag;Ldev/openfeature/kotlin/sdk/EvaluationContext;)Ljava/lang/String;
+}
+
+public final class dev/openfeature/kotlin/sdk/providers/memory/Flag {
+	public static final field Companion Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Companion;
+	public fun <init> (Ljava/util/Map;Ljava/lang/String;Ldev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator;Ldev/openfeature/kotlin/sdk/EvaluationMetadata;Z)V
+	public synthetic fun <init> (Ljava/util/Map;Ljava/lang/String;Ldev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator;Ldev/openfeature/kotlin/sdk/EvaluationMetadata;ZILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public final fun component1 ()Ljava/util/Map;
+	public final fun component2 ()Ljava/lang/String;
+	public final fun component3 ()Ldev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator;
+	public final fun component4 ()Ldev/openfeature/kotlin/sdk/EvaluationMetadata;
+	public final fun component5 ()Z
+	public final fun copy (Ljava/util/Map;Ljava/lang/String;Ldev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator;Ldev/openfeature/kotlin/sdk/EvaluationMetadata;Z)Ldev/openfeature/kotlin/sdk/providers/memory/Flag;
+	public static synthetic fun copy$default (Ldev/openfeature/kotlin/sdk/providers/memory/Flag;Ljava/util/Map;Ljava/lang/String;Ldev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator;Ldev/openfeature/kotlin/sdk/EvaluationMetadata;ZILjava/lang/Object;)Ldev/openfeature/kotlin/sdk/providers/memory/Flag;
+	public fun equals (Ljava/lang/Object;)Z
+	public final fun getContextEvaluator ()Ldev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator;
+	public final fun getDefaultVariant ()Ljava/lang/String;
+	public final fun getDisabled ()Z
+	public final fun getFlagMetadata ()Ldev/openfeature/kotlin/sdk/EvaluationMetadata;
+	public final fun getVariants ()Ljava/util/Map;
+	public fun hashCode ()I
+	public fun toString ()Ljava/lang/String;
+}
+
+public final class dev/openfeature/kotlin/sdk/providers/memory/Flag$Builder {
+	public fun <init> ()V
+	public final fun build ()Ldev/openfeature/kotlin/sdk/providers/memory/Flag;
+	public final fun contextEvaluator (Ldev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator;)Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Builder;
+	public final fun defaultVariant (Ljava/lang/String;)Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Builder;
+	public final fun disabled (Z)Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Builder;
+	public final fun flagMetadata (Ldev/openfeature/kotlin/sdk/EvaluationMetadata;)Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Builder;
+	public final fun variant (Ljava/lang/String;Ljava/lang/Object;)Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Builder;
+	public final fun variants (Ljava/util/Map;)Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Builder;
+}
+
+public final class dev/openfeature/kotlin/sdk/providers/memory/Flag$Companion {
+	public final fun builder ()Ldev/openfeature/kotlin/sdk/providers/memory/Flag$Builder;
+}
+
+public final class dev/openfeature/kotlin/sdk/providers/memory/InMemoryProvider : dev/openfeature/kotlin/sdk/FeatureProvider {
+	public fun <init> ()V
+	public fun <init> (Ljava/util/Map;)V
+	public synthetic fun <init> (Ljava/util/Map;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun getBooleanEvaluation (Ljava/lang/String;ZLdev/openfeature/kotlin/sdk/EvaluationContext;)Ldev/openfeature/kotlin/sdk/ProviderEvaluation;
+	public fun getDoubleEvaluation (Ljava/lang/String;DLdev/openfeature/kotlin/sdk/EvaluationContext;)Ldev/openfeature/kotlin/sdk/ProviderEvaluation;
+	public fun getHooks ()Ljava/util/List;
+	public fun getIntegerEvaluation (Ljava/lang/String;ILdev/openfeature/kotlin/sdk/EvaluationContext;)Ldev/openfeature/kotlin/sdk/ProviderEvaluation;
+	public fun getMetadata ()Ldev/openfeature/kotlin/sdk/ProviderMetadata;
+	public fun getObjectEvaluation (Ljava/lang/String;Ldev/openfeature/kotlin/sdk/Value;Ldev/openfeature/kotlin/sdk/EvaluationContext;)Ldev/openfeature/kotlin/sdk/ProviderEvaluation;
+	public fun getStringEvaluation (Ljava/lang/String;Ljava/lang/String;Ldev/openfeature/kotlin/sdk/EvaluationContext;)Ldev/openfeature/kotlin/sdk/ProviderEvaluation;
+	public fun initialize (Ldev/openfeature/kotlin/sdk/EvaluationContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun observe ()Lkotlinx/coroutines/flow/Flow;
+	public fun onContextSet (Ldev/openfeature/kotlin/sdk/EvaluationContext;Ldev/openfeature/kotlin/sdk/EvaluationContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun shutdown ()V
+	public fun track (Ljava/lang/String;Ldev/openfeature/kotlin/sdk/EvaluationContext;Ldev/openfeature/kotlin/sdk/TrackingEventDetails;)V
+	public final fun updateFlags (Ljava/util/Map;)V
+}
+
+public final class dev/openfeature/kotlin/sdk/providers/memory/InMemoryProvider$InMemoryProviderMetadata : dev/openfeature/kotlin/sdk/ProviderMetadata {
+	public fun <init> (Ljava/lang/String;)V
+	public fun getName ()Ljava/lang/String;
+	public fun getOriginalMetadata ()Ljava/util/Map;
+}
+

kotlin-sdk/build.gradle.kts

@@ -38,6 +38,9 @@ kotlin {
                 }
             }
         }
+        testRuns["test"].executionTask.configure {
+            useJUnitPlatform()
+        }
     }
     linuxX64 {}
     js {
@@ -59,11 +62,19 @@ kotlin {
             implementation("org.jetbrains.kotlinx:kotlinx-collections-immutable:0.4.0")
         }
         commonTest.dependencies {
-            implementation("org.jetbrains.kotlin:kotlin-test:2.2.10")
+            implementation(kotlin("test"))
             implementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.7.3")
             implementation("org.jetbrains.kotlinx:kotlinx-coroutines-debug:1.7.3")
             implementation("org.jetbrains.kotlinx:atomicfu:0.29.0")
         }
+        val jvmTest by getting {
+            resources.srcDir("../spec/specification/assets/gherkin")
+            dependencies {
+                implementation("org.junit.platform:junit-platform-suite:1.10.1")
+                implementation("io.cucumber:cucumber-java:7.15.0")
+                implementation("io.cucumber:cucumber-junit-platform-engine:7.15.0")
+            }
+        }
     }
 }
 

kotlin-sdk/src/commonMain/kotlin/dev/openfeature/kotlin/sdk/providers/memory/ContextEvaluator.kt

@@ -0,0 +1,18 @@
+package dev.openfeature.kotlin.sdk.providers.memory
+
+import dev.openfeature.kotlin.sdk.EvaluationContext
+
+/**
+ * Context evaluator - use for resolving flag according to evaluation context, for handling targeting.
+ */
+fun interface ContextEvaluator<T> {
+    /**
+     * Evaluates the flag's specific variant based on the provided evaluation context.
+     *
+     * @param flag the feature flag representation
+     * @param evaluationContext the context used for targeting
+     * @return the resolved variant key (a string matching a key in the flag's variants map),
+     *         or null if no match was found.
+     */
+    fun evaluate(flag: Flag<T>, evaluationContext: EvaluationContext?): String?
+}

kotlin-sdk/src/commonMain/kotlin/dev/openfeature/kotlin/sdk/providers/memory/Flag.kt

@@ -0,0 +1,43 @@
+package dev.openfeature.kotlin.sdk.providers.memory
+
+import dev.openfeature.kotlin.sdk.EvaluationMetadata
+
+/**
+ * Flag representation for the in-memory provider.
+ */
+data class Flag<T>(
+    val variants: Map<String, T>,
+    val defaultVariant: String? = null,
+    val contextEvaluator: ContextEvaluator<T>? = null,
+    val flagMetadata: EvaluationMetadata? = null,
+    val disabled: Boolean = false
+) {
+    init {
+        if (defaultVariant != null && !variants.containsKey(defaultVariant)) {
+            throw IllegalArgumentException("defaultVariant ($defaultVariant) is not present in variants map")
+        }
+    }
+
+    companion object {
+        fun <T> builder() = Builder<T>()
+    }
+
+    class Builder<T> {
+        private val variants = mutableMapOf<String, T>()
+        private var defaultVariant: String? = null
+        private var contextEvaluator: ContextEvaluator<T>? = null
+        private var flagMetadata: EvaluationMetadata? = null
+        private var disabled: Boolean = false
+
+        fun variant(name: String, value: T) = apply { this.variants[name] = value }
+        fun variants(variants: Map<String, T>) = apply { this.variants.putAll(variants) }
+        fun defaultVariant(defaultVariant: String?) = apply { this.defaultVariant = defaultVariant }
+        fun contextEvaluator(contextEvaluator: ContextEvaluator<T>) = apply { this.contextEvaluator = contextEvaluator }
+        fun flagMetadata(flagMetadata: EvaluationMetadata) = apply { this.flagMetadata = flagMetadata }
+        fun disabled(disabled: Boolean) = apply { this.disabled = disabled }
+
+        fun build(): Flag<T> {
+            return Flag(variants.toMap(), defaultVariant, contextEvaluator, flagMetadata, disabled)
+        }
+    }
+}