refactor(telemetry): update telemetry attributes and remove unused evaluation data

packages/shared/src/evaluation/evaluation.ts

@@ -3,7 +3,7 @@ import type { JsonValue } from '../types/structure';
 export type FlagValueType = 'boolean' | 'string' | 'number' | 'object';
 
 /**
- * Represents a JSON node value, or Date.
+ * Represents a JSON node value.
  */
 export type FlagValue = boolean | string | number | JsonValue;
 

packages/shared/src/telemetry/attributes.ts

@@ -20,6 +20,14 @@ export const TelemetryAttribute = {
    * - example: `flag_not_found`
    */
   ERROR_CODE: 'error.type',
+  /**
+   * A message explaining the nature of an error occurring during flag evaluation.
+   *
+   * - type: `string`
+   * - requirement level: `recommended`
+   * - example: `Flag not found`
+   */
+  ERROR_MESSAGE: 'error.message',
   /**
    * A semantic identifier for an evaluated flag value.
    *
@@ -28,39 +36,40 @@ export const TelemetryAttribute = {
    * - condition: variant is defined on the evaluation details
    * - example: `blue`; `on`; `true`
    */
-  VARIANT: 'feature_flag.variant',
+  VARIANT: 'feature_flag.result.variant',
   /**
-   * The unique identifier for the flag evaluation context. For example, the targeting key.
+   * The evaluated value of the feature flag.
    *
-   * - type: `string`
-   * - requirement level: `recommended`
-   * - example: `5157782b-2203-4c80-a857-dbbd5e7761db`
+   * - type: `undefined`
+   * - requirement level: `conditionally required`
+   * - condition: variant is not defined on the evaluation details
+   * - example: `#ff0000`; `1`; `true`
    */
-  CONTEXT_ID: 'feature_flag.context.id',
+  VALUE: 'feature_flag.result.value',
   /**
-   * A message explaining the nature of an error occurring during flag evaluation.
+   * The unique identifier for the flag evaluation context. For example, the targeting key.
    *
    * - type: `string`
    * - requirement level: `recommended`
-   * - example: `Flag not found`
+   * - example: `5157782b-2203-4c80-a857-dbbd5e7761db`
    */
-  ERROR_MESSAGE: 'feature_flag.evaluation.error.message',
+  CONTEXT_ID: 'feature_flag.context.id',
   /**
    * The reason code which shows how a feature flag value was determined.
    *
    * - type: `string`
    * - requirement level: `recommended`
    * - example: `targeting_match`
    */
-  REASON: 'feature_flag.evaluation.reason',
+  REASON: 'feature_flag.result.reason',
   /**
    * Describes a class of error the operation ended with.
    *
    * - type: `string`
    * - requirement level: `recommended`
    * - example: `flag_not_found`
    */
-  PROVIDER: 'feature_flag.provider_name',
+  PROVIDER: 'feature_flag.provider.name',
   /**
    * The identifier of the flag set to which the feature flag belongs.
    *

packages/shared/src/telemetry/evaluation-event.ts

@@ -1,14 +1,19 @@
 import { ErrorCode, StandardResolutionReasons, type EvaluationDetails, type FlagValue } from '../evaluation/evaluation';
 import type { HookContext } from '../hooks/hooks';
-import type { JsonValue } from '../types';
 import { TelemetryAttribute } from './attributes';
-import { TelemetryEvaluationData } from './evaluation-data';
 import { TelemetryFlagMetadata } from './flag-metadata';
 
 type EvaluationEvent = {
+  /**
+   * The name of the feature flag evaluation event.
+   */
   name: string;
-  attributes: Record<string, string | number | boolean>;
-  body: Record<string, JsonValue>;
+  /**
+   * The attributes of an OpenTelemetry compliant event for flag evaluation.
+   * @experimental The attributes are subject to change.
+   * @see https://opentelemetry.io/docs/specs/semconv/feature-flags/feature-flags-logs/
+   */
+  attributes: Record<string, string | number | boolean | FlagValue>;
 };
 
 const FLAG_EVALUATION_EVENT_NAME = 'feature_flag.evaluation';
@@ -28,12 +33,11 @@ export function createEvaluationEvent(
     [TelemetryAttribute.PROVIDER]: hookContext.providerMetadata.name,
     [TelemetryAttribute.REASON]: (evaluationDetails.reason ?? StandardResolutionReasons.UNKNOWN).toLowerCase(),
   };
-  const body: EvaluationEvent['body'] = {};
 
   if (evaluationDetails.variant) {
     attributes[TelemetryAttribute.VARIANT] = evaluationDetails.variant;
   } else {
-    body[TelemetryEvaluationData.VALUE] = evaluationDetails.value;
+    attributes[TelemetryAttribute.VALUE] = evaluationDetails.value;
   }
 
   const contextId =
@@ -62,6 +66,5 @@ export function createEvaluationEvent(
   return {
     name: FLAG_EVALUATION_EVENT_NAME,
     attributes,
-    body,
   };
 }

packages/shared/src/telemetry/index.ts

@@ -1,4 +1,3 @@
 export * from './attributes';
-export * from './evaluation-data';
 export * from './flag-metadata';
 export * from './evaluation-event';

packages/shared/test/telemetry.spec.ts

@@ -1,7 +1,7 @@
 import { createEvaluationEvent } from '../src/telemetry/evaluation-event';
 import { ErrorCode, StandardResolutionReasons, type EvaluationDetails } from '../src/evaluation/evaluation';
 import type { HookContext } from '../src/hooks/hooks';
-import { TelemetryAttribute, TelemetryFlagMetadata, TelemetryEvaluationData } from '../src/telemetry';
+import { TelemetryAttribute, TelemetryFlagMetadata } from '../src/telemetry';
 
 describe('evaluationEvent', () => {
   const flagKey = 'test-flag';
@@ -43,9 +43,7 @@ describe('evaluationEvent', () => {
       [TelemetryAttribute.PROVIDER]: 'test-provider',
       [TelemetryAttribute.REASON]: StandardResolutionReasons.STATIC.toLowerCase(),
       [TelemetryAttribute.CONTEXT_ID]: 'test-target',
-    });
-    expect(result.body).toEqual({
-      [TelemetryEvaluationData.VALUE]: true,
+      [TelemetryAttribute.VALUE]: true,
     });
   });
 
@@ -61,7 +59,7 @@ describe('evaluationEvent', () => {
     const result = createEvaluationEvent(mockHookContext, details);
 
     expect(result.attributes[TelemetryAttribute.VARIANT]).toBe('test-variant');
-    expect(result.attributes[TelemetryEvaluationData.VALUE]).toBeUndefined();
+    expect(result.attributes[TelemetryAttribute.VALUE]).toBeUndefined();
   });
 
   it('should include flag metadata when provided', () => {