Evaluate without impressions: add impressionsDisabled option to feature evaluation

CHANGES.txt

@@ -1,3 +1,6 @@
+2.10.0 (December 16, 2025)
+ - Added property `impressionsDisabled` in getTreatment(s) `evaluationOptions` parameter, to disable impressions per evaluations.
+
 2.9.0 (November 26, 2025)
  - Updated the SDK’s initial synchronization in Node.js (server-side) to use the `startup.requestTimeoutBeforeReady` and `startup.retriesOnFailureBeforeReady` options to control the timeout and retry behavior of segment requests.
  - Updated the order of storage operations to prevent inconsistent states when using the `LOCALSTORAGE` storage type and the browser’s `localStorage` fails due to quota limits.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@splitsoftware/splitio-commons",
-  "version": "2.9.0",
+  "version": "2.9.1-rc.2",
   "description": "Split JavaScript SDK common components",
   "main": "cjs/index.js",
   "module": "esm/index.js",

src/evaluator/index.ts

@@ -30,6 +30,7 @@ export function evaluateFeature(
   splitName: string,
   attributes: SplitIO.Attributes | undefined,
   storage: IStorageSync | IStorageAsync,
+  options?: SplitIO.EvaluationOptions
 ): MaybeThenable<IEvaluationResult> {
   let parsedSplit;
 
@@ -47,6 +48,7 @@ export function evaluateFeature(
       split,
       attributes,
       storage,
+      options,
     )).catch(
       // Exception on async `getSplit` storage. For example, when the storage is redis or
       // pluggable and there is a connection issue and we can't retrieve the split to be evaluated
@@ -60,6 +62,7 @@ export function evaluateFeature(
     parsedSplit,
     attributes,
     storage,
+    options,
   );
 }
 
@@ -69,6 +72,7 @@ export function evaluateFeatures(
   splitNames: string[],
   attributes: SplitIO.Attributes | undefined,
   storage: IStorageSync | IStorageAsync,
+  options?: SplitIO.EvaluationOptions,
 ): MaybeThenable<Record<string, IEvaluationResult>> {
   let parsedSplits;
 
@@ -80,13 +84,13 @@ export function evaluateFeatures(
   }
 
   return thenable(parsedSplits) ?
-    parsedSplits.then(splits => getEvaluations(log, key, splitNames, splits, attributes, storage))
+    parsedSplits.then(splits => getEvaluations(log, key, splitNames, splits, attributes, storage, options))
       .catch(() => {
         // Exception on async `getSplits` storage. For example, when the storage is redis or
         // pluggable and there is a connection issue and we can't retrieve the split to be evaluated
         return treatmentsException(splitNames);
       }) :
-    getEvaluations(log, key, splitNames, parsedSplits, attributes, storage);
+    getEvaluations(log, key, splitNames, parsedSplits, attributes, storage, options);
 }
 
 export function evaluateFeaturesByFlagSets(
@@ -96,6 +100,7 @@ export function evaluateFeaturesByFlagSets(
   attributes: SplitIO.Attributes | undefined,
   storage: IStorageSync | IStorageAsync,
   method: string,
+  options?: SplitIO.EvaluationOptions,
 ): MaybeThenable<Record<string, IEvaluationResult>> {
   let storedFlagNames: MaybeThenable<Set<string>[]>;
 
@@ -111,7 +116,7 @@ export function evaluateFeaturesByFlagSets(
     }
 
     return featureFlags.size ?
-      evaluateFeatures(log, key, setToArray(featureFlags), attributes, storage) :
+      evaluateFeatures(log, key, setToArray(featureFlags), attributes, storage, options) :
       {};
   }
 
@@ -138,6 +143,7 @@ function getEvaluation(
   splitJSON: ISplit | null,
   attributes: SplitIO.Attributes | undefined,
   storage: IStorageSync | IStorageAsync,
+  options?: SplitIO.EvaluationOptions,
 ): MaybeThenable<IEvaluationResult> {
   let evaluation: MaybeThenable<IEvaluationResult> = {
     treatment: CONTROL,
@@ -154,14 +160,16 @@ function getEvaluation(
       return evaluation.then(result => {
         result.changeNumber = splitJSON.changeNumber;
         result.config = splitJSON.configurations && splitJSON.configurations[result.treatment] || null;
-        result.impressionsDisabled = splitJSON.impressionsDisabled;
+        // @ts-expect-error impressionsDisabled is not exposed in the public typings yet.
+        result.impressionsDisabled = options?.impressionsDisabled || splitJSON.impressionsDisabled;
 
         return result;
       });
     } else {
       evaluation.changeNumber = splitJSON.changeNumber;
       evaluation.config = splitJSON.configurations && splitJSON.configurations[evaluation.treatment] || null;
-      evaluation.impressionsDisabled = splitJSON.impressionsDisabled;
+      // @ts-expect-error impressionsDisabled is not exposed in the public typings yet.
+      evaluation.impressionsDisabled = options?.impressionsDisabled || splitJSON.impressionsDisabled;
     }
   }
 
@@ -175,6 +183,7 @@ function getEvaluations(
   splits: Record<string, ISplit | null>,
   attributes: SplitIO.Attributes | undefined,
   storage: IStorageSync | IStorageAsync,
+  options?: SplitIO.EvaluationOptions,
 ): MaybeThenable<Record<string, IEvaluationResult>> {
   const result: Record<string, IEvaluationResult> = {};
   const thenables: Promise<void>[] = [];
@@ -184,7 +193,8 @@ function getEvaluations(
       key,
       splits[splitName],
       attributes,
-      storage
+      storage,
+      options
     );
     if (thenable(evaluation)) {
       thenables.push(evaluation.then(res => {

src/sdkClient/__tests__/clientInputValidation.spec.ts

@@ -107,4 +107,24 @@ describe('clientInputValidationDecorator', () => {
 
     expect(logSpy).not.toBeCalled();
   });
+
+  test('should ignore the properties in the 4th argument if an empty object is passed', () => {
+    expect(clientWithValidation.getTreatment('key', 'ff', undefined, { impressionsDisabled: true })).toBe(EVALUATION_RESULT);
+    expect(client.getTreatment).toHaveBeenLastCalledWith('key', 'ff', undefined, { impressionsDisabled: true });
+
+    expect(clientWithValidation.getTreatment('key', 'ff', undefined, { impressionsDisabled: false })).toBe(EVALUATION_RESULT);
+    expect(client.getTreatment).toHaveBeenLastCalledWith('key', 'ff', undefined, undefined);
+
+    expect(clientWithValidation.getTreatment('key', 'ff', undefined, { impressionsDisabled: true })).toBe(EVALUATION_RESULT);
+    expect(client.getTreatment).toHaveBeenLastCalledWith('key', 'ff', undefined, { impressionsDisabled: true });
+
+    expect(clientWithValidation.getTreatment('key', 'ff', undefined, { impressionsDisabled: null })).toBe(EVALUATION_RESULT);
+    expect(client.getTreatment).toHaveBeenLastCalledWith('key', 'ff', undefined, undefined);
+
+    expect(clientWithValidation.getTreatment('key', 'ff', undefined, { impressionsDisabled: false })).toBe(EVALUATION_RESULT);
+    expect(client.getTreatment).toHaveBeenLastCalledWith('key', 'ff', undefined, undefined); // impressionsDisabled false is the default behavior, so we don't pass it along
+
+    expect(clientWithValidation.getTreatment('key', 'ff', undefined, { properties: undefined })).toBe(EVALUATION_RESULT);
+    expect(client.getTreatment).toHaveBeenLastCalledWith('key', 'ff', undefined, undefined);
+  });
 });

src/sdkClient/client.ts

@@ -52,7 +52,7 @@ export function clientFactory(params: ISdkFactoryContext): SplitIO.IClient | Spl
     };
 
     const evaluation = readinessManager.isReadyFromCache() ?
-      evaluateFeature(log, key, featureFlagName, attributes, storage) :
+      evaluateFeature(log, key, featureFlagName, attributes, storage, options) :
       isAsync ? // If the SDK is not ready, treatment may be incorrect due to having splits but not segments data, or storage is not connected
         Promise.resolve(treatmentNotReady) :
         treatmentNotReady;
@@ -81,7 +81,7 @@ export function clientFactory(params: ISdkFactoryContext): SplitIO.IClient | Spl
     };
 
     const evaluations = readinessManager.isReadyFromCache() ?
-      evaluateFeatures(log, key, featureFlagNames, attributes, storage) :
+      evaluateFeatures(log, key, featureFlagNames, attributes, storage, options) :
       isAsync ? // If the SDK is not ready, treatment may be incorrect due to having splits but not segments data, or storage is not connected
         Promise.resolve(treatmentsNotReady(featureFlagNames)) :
         treatmentsNotReady(featureFlagNames);
@@ -110,7 +110,7 @@ export function clientFactory(params: ISdkFactoryContext): SplitIO.IClient | Spl
     };
 
     const evaluations = readinessManager.isReadyFromCache() ?
-      evaluateFeaturesByFlagSets(log, key, flagSetNames, attributes, storage, methodName) :
+      evaluateFeaturesByFlagSets(log, key, flagSetNames, attributes, storage, methodName, options) :
       isAsync ?
         Promise.resolve({}) :
         {};

src/utils/inputValidation/eventProperties.ts

@@ -70,7 +70,13 @@ export function validateEventProperties(log: ILogger, maybeProperties: any, meth
 export function validateEvaluationOptions(log: ILogger, maybeOptions: any, method: string): SplitIO.EvaluationOptions | undefined {
   if (isObject(maybeOptions)) {
     const properties = validateEventProperties(log, maybeOptions.properties, method).properties;
-    return properties && Object.keys(properties).length > 0 ? { properties } : undefined;
+    let options =  properties && Object.keys(properties).length > 0 ? { properties } : undefined;
+
+    const impressionsDisabled = maybeOptions.impressionsDisabled;
+    if (!impressionsDisabled) return options;
+
+    // @ts-expect-error impressionsDisabled is not exposed in the public typings yet.
+    return options ? { ...options, impressionsDisabled } : { impressionsDisabled };
   } else if (maybeOptions) {
     log.error(ERROR_NOT_PLAIN_OBJECT, [method, 'evaluation options']);
   }

types/splitio.d.ts

@@ -918,8 +918,16 @@ declare namespace SplitIO {
    * Evaluation options object for getTreatment methods.
    */
   type EvaluationOptions = {
+    /**
+     * Whether the evaluation/s will track impressions or not.
+     *
+     * @defaultValue `false`
+     */
+    // impressionsDisabled?: boolean;
     /**
      * Optional properties to append to the generated impression object sent to Split backend.
+     *
+     * @defaultValue `undefined`
      */
     properties?: Properties;
   }