feat: Clone OptimizelyUserContext before calling decide api (#643)

* Clone OptimizelyUsercOntext before calling decide apis

* Add description to decision params

Author: yavorona

packages/optimizely-sdk/lib/optimizely_decision/index.ts

@@ -17,11 +17,17 @@ import OptimizelyUserContext from '../optimizely_user_context';
 
 export interface OptimizelyDecision {
   variationKey: string | null;
+  // The boolean value indicating if the flag is enabled or not
   enabled: boolean;
+  // The collection of variables associated with the decision
   variables: { [variableKey: string]: unknown };
+  // The rule key of the decision
   ruleKey: string | null;
+  // The flag key for which the decision has been made for
   flagKey: string;
+  // A copy of the user context for which the decision has been made for
   userContext: OptimizelyUserContext;
+  // An array of error/info messages describing why the decision has been made.
   reasons: string[];
 }
 

packages/optimizely-sdk/lib/optimizely_user_context/index.ts

@@ -69,7 +69,7 @@ export default class OptimizelyUserContext {
     options: OptimizelyDecideOptions[] = []
   ): OptimizelyDecision {
 
-    return this.optimizely.decide(this, key, options);
+    return this.optimizely.decide(this.cloneUserContext(), key, options);
   }
 
   /**
@@ -85,7 +85,7 @@ export default class OptimizelyUserContext {
     options: OptimizelyDecideOptions[] = [],
   ): { [key: string]: OptimizelyDecision } {
 
-    return this.optimizely.decideForKeys(this, keys, options);
+    return this.optimizely.decideForKeys(this.cloneUserContext(), keys, options);
   }
 
   /**
@@ -97,7 +97,7 @@ export default class OptimizelyUserContext {
     options: OptimizelyDecideOptions[] = []
   ): { [key: string]: OptimizelyDecision } {
 
-    return this.optimizely.decideAll(this, options);
+    return this.optimizely.decideAll(this.cloneUserContext(), options);
   }
 
   /**
@@ -108,4 +108,12 @@ export default class OptimizelyUserContext {
   trackEvent(eventName: string, eventTags?: EventTags): void {
     this.optimizely.track(eventName, this.userId, this.attributes, eventTags);
   }
+
+  private cloneUserContext(): OptimizelyUserContext {
+    return new OptimizelyUserContext({
+      optimizely: this.getOptimizely(),
+      userId: this.getUserId(),
+      attributes: this.getAttributes(),
+    })
+  }
 }