fix: variant stickiness (#70)

* fix: variant stickiness
* chore: update client specification

lib/package.json

@@ -36,7 +36,7 @@
     "@types/react": "18.2.63",
     "@types/react-dom": "18.2.19",
     "@types/semver": "7.5.8",
-    "@unleash/client-specification": "5.1.0",
+    "@unleash/client-specification": "5.1.4",
     "@vitest/coverage-v8": "^1.3.1",
     "eslint-config-custom": "workspace:*",
     "next": "14.1.2",

lib/src/core/client/strategy/strategy.ts

@@ -251,8 +251,10 @@ export class Strategy {
     );
 
     if (enabled && Array.isArray(variants) && variants.length > 0) {
+      const stickiness = variants[0].stickiness || parameters.stickiness;
       const variantDefinition = selectVariantDefinition(
         parameters.groupId,
+        stickiness,
         variants,
         context
       );

lib/src/core/variant.ts

@@ -62,6 +62,7 @@ function findOverride(
 
 export function selectVariantDefinition(
   groupId: string,
+  stickiness: string | undefined,
   variants: VariantDefinition[],
   context: Context
 ): VariantDefinition | null {
@@ -74,8 +75,6 @@ export function selectVariantDefinition(
     return variantOverride;
   }
 
-  const { stickiness } = variants[0];
-
   const target = normalizedValue(
     getSeed(context, stickiness),
     groupId,
@@ -103,5 +102,6 @@ export function selectVariant(
   feature: FeatureInterface,
   context: Context
 ): VariantDefinition | null {
-  return selectVariantDefinition(feature.name, feature.variants || [], context);
+  const stickiness = feature.variants?.[0]?.stickiness ?? undefined;
+  return selectVariantDefinition(feature.name, stickiness, feature.variants || [], context);
 }