feat: add eval reasons to WASM Bucketing

lib/shared/bucketing-assembly-script/__tests__/protobufVariableHelper.ts

@@ -1,4 +1,9 @@
-import { SDKVariable, VariableType as VariableTypeStr } from '@devcycle/types'
+import {
+    EVAL_REASON_DETAILS,
+    EVAL_REASONS,
+    SDKVariable,
+    VariableType as VariableTypeStr,
+} from '@devcycle/types'
 import { variableForUser_PB, VariableType } from './bucketingImportHelper'
 import { VariableForUserParams_PB, SDKVariable_PB } from '../protobuf/compiled'
 
@@ -9,6 +14,10 @@ type SDKVariable_PB_Type = {
     boolValue: boolean
     doubleValue: number
     stringValue: string
+    eval?: {
+        reason: EVAL_REASONS
+        details?: string
+    }
     _feature?: {
         value: string
         isNull: boolean
@@ -22,6 +31,7 @@ const pbSDKVariableToJS = (pbSDKVariable: SDKVariable_PB_Type): SDKVariable => {
             key: pbSDKVariable.key,
             value: pbSDKVariable.boolValue,
             type: VariableTypeStr.boolean,
+            eval: pbSDKVariable.eval,
             _feature: pbSDKVariable._feature?.value,
         }
     } else if (pbSDKVariable.type === 1) {
@@ -30,6 +40,7 @@ const pbSDKVariableToJS = (pbSDKVariable: SDKVariable_PB_Type): SDKVariable => {
             key: pbSDKVariable.key,
             value: pbSDKVariable.doubleValue,
             type: VariableTypeStr.number,
+            eval: pbSDKVariable.eval,
             _feature: pbSDKVariable._feature?.value,
         }
     } else if (pbSDKVariable.type === 2) {
@@ -38,6 +49,7 @@ const pbSDKVariableToJS = (pbSDKVariable: SDKVariable_PB_Type): SDKVariable => {
             key: pbSDKVariable.key,
             value: pbSDKVariable.stringValue,
             type: VariableTypeStr.string,
+            eval: pbSDKVariable.eval,
             _feature: pbSDKVariable._feature?.value,
         }
     } else if (pbSDKVariable.type === 3) {
@@ -46,6 +58,7 @@ const pbSDKVariableToJS = (pbSDKVariable: SDKVariable_PB_Type): SDKVariable => {
             key: pbSDKVariable.key,
             value: JSON.parse(pbSDKVariable.stringValue),
             type: VariableTypeStr.json,
+            eval: pbSDKVariable.eval,
             _feature: pbSDKVariable._feature?.value,
         }
     }

lib/shared/bucketing-assembly-script/__tests__/types/protobuf.test.ts

@@ -105,6 +105,10 @@ describe('protobuf variable tests', () => {
             isNull: true,
             value: '',
         },
+        eval: {
+            details: 'User ID AND Country',
+            reason: 'TARGETING_MATCH',
+        },
         key: 'swagTest',
         stringValue: 'YEEEEOWZA',
         type: VariableType.String,
@@ -288,7 +292,6 @@ describe('protobuf variable tests', () => {
                     boolValue: true,
                     doubleValue: 0,
                     stringValue: '',
-                    evalReason: { value: '', isNull: true },
                     _feature: {
                         value: '615356f120ed334a6054564f',
                         isNull: false,

lib/shared/bucketing-assembly-script/__tests__/variable.test.ts

@@ -25,6 +25,10 @@ describe('variableForUser tests', () => {
         expect(variable1).toEqual({
             _id: '615356f120ed334a6054564c',
             _feature: '614ef6aa473928459060721a',
+            eval: {
+                details: 'User ID AND Country',
+                reason: 'TARGETING_MATCH',
+            },
             key: 'swagTest',
             type: 'String',
             value: 'YEEEEOWZA',
@@ -38,6 +42,10 @@ describe('variableForUser tests', () => {
         expect(variable2).toEqual({
             _id: '61538237b0a70b58ae6af71y',
             _feature: '614ef6aa473928459060721a',
+            eval: {
+                details: 'User ID AND Country',
+                reason: 'TARGETING_MATCH',
+            },
             key: 'bool-var',
             type: 'Boolean',
             value: false,
@@ -51,6 +59,10 @@ describe('variableForUser tests', () => {
         expect(variable3).toEqual({
             _id: '61538237b0a70b58ae6af71s',
             _feature: '614ef6aa473928459060721a',
+            eval: {
+                details: 'User ID AND Country',
+                reason: 'TARGETING_MATCH',
+            },
             key: 'num-var',
             type: 'Number',
             value: 610.61,
@@ -64,6 +76,10 @@ describe('variableForUser tests', () => {
         expect(variable4).toEqual({
             _id: '61538237b0a70b58ae6af71q',
             _feature: '614ef6aa473928459060721a',
+            eval: {
+                details: 'User ID AND Country',
+                reason: 'TARGETING_MATCH',
+            },
             key: 'json-var',
             type: 'JSON',
             value: '{"hello":"world","num":610,"bool":true}',
@@ -85,6 +101,10 @@ describe('variableForUser tests', () => {
         expect(variable1).toEqual({
             _id: '615356f120ed334a6054564c',
             _feature: '614ef6aa473928459060721a',
+            eval: {
+                details: 'User ID AND Country',
+                reason: 'TARGETING_MATCH',
+            },
             key: 'swagTest',
             type: 'String',
             value: 'YEEEEOWZA',

lib/shared/bucketing-assembly-script/assembly/bucketing/bucketing.ts

@@ -14,6 +14,9 @@ import {
     Variation,
     FeatureVariation,
     FeatureV2 as Feature,
+    EvalReason,
+    EVAL_REASONS,
+    EVAL_REASON_DETAILS,
 } from '../types'
 
 import { murmurhashV3 } from '../helpers/murmurhash'
@@ -131,14 +134,20 @@ export function _doesUserPassRollout(
 class SegmentedFeatureData {
     public feature: PublicFeature
     public target: PublicTarget
+    public reasonDetails: string | null
+}
+
+class TargetResult { 
+    public target: PublicTarget
+    public reasonDetails: string
 }
 
 function evaluateSegmentationForFeature(
     config: ConfigBody,
     feature: Feature,
     user: DVCPopulatedUser,
     clientCustomData: JSON.Obj,
-): Target | null {
+): TargetResult | null {
     // Returns the first target for which the user passes segmentation
     for (let i = 0; i < feature.configuration.targets.length; i++) {
         const target = feature.configuration.targets[i]
@@ -150,15 +159,20 @@ function evaluateSegmentationForFeature(
             const rolloutHash = boundedHashData.rolloutHash
             doesUserPassRollout = _doesUserPassRollout(target.rollout, rolloutHash)
         }
-        if (
-            doesUserPassRollout && _evaluateOperator(
+
+        if (doesUserPassRollout) {
+            const evalResult = _evaluateOperator(
                 target._audience.filters,
                 config.audiences,
                 user,
                 clientCustomData,
             )
-        ) {
-            return target
+            if(evalResult.result) {
+                return {
+                    target,
+                    reasonDetails: evalResult.reasonDetails || ""
+                }
+            }
         }
     }
     return null
@@ -197,6 +211,7 @@ export function getSegmentedFeatureDataFromConfig(
 class TargetAndHashes {
     public target: Target
     public boundedHashData: BoundedHash
+    public reasonDetails: string
 }
 
 function doesUserQualifyForFeature(
@@ -205,13 +220,15 @@ function doesUserQualifyForFeature(
     user: DVCPopulatedUser,
     clientCustomData: JSON.Obj,
 ): TargetAndHashes | null {
-    const target = evaluateSegmentationForFeature(
+    const targetResult = evaluateSegmentationForFeature(
         config,
         feature,
         user,
         clientCustomData,
     )
-    if (!target) return null
+    if (!targetResult) return null
+    const target = targetResult.target
+    const reasonDetails = targetResult.reasonDetails
 
     const bucketingValue = _getUserValueForBucketingKey( user, target )
     const boundedHashData = _generateBoundedHashes(bucketingValue, target._id)
@@ -223,27 +240,34 @@ function doesUserQualifyForFeature(
     return {
         target,
         boundedHashData,
+        reasonDetails
     }
 }
 
 export function bucketUserForVariation(
     feature: Feature,
     targetAndHashes: TargetAndHashes,
 ): Variation {
-    const variation_id = targetAndHashes.target.decideTargetVariation(
+    const variationResult = targetAndHashes.target.decideTargetVariation(
         targetAndHashes.boundedHashData.bucketingHash,
     )
-    const variation = feature.getVariationById(variation_id)
+    const variation = feature.getVariationById(variationResult.variation)
     if (variation) {
         return variation
     } else {
-        throw new Error(`Config missing variation: ${variation_id}`)
+        throw new Error(`Config missing variation: ${variationResult.variation}`)
     }
 }
 
-class BucketedFeature {
-    feature: Feature
-    variation: Variation
+function _getEvalReason(
+    targetAndHashes: TargetAndHashes 
+): EvalReason {
+    const target = targetAndHashes.target
+    const hasRollout = target.rollout !== null
+    const hasMultipleDistributions = target.distribution.length !== 1
+
+    const reason = hasRollout || hasMultipleDistributions ? EVAL_REASONS.SPLIT : EVAL_REASONS.TARGETING_MATCH
+    return  new EvalReason(reason, targetAndHashes.reasonDetails)
 }
 
 export function _generateBucketedConfig(
@@ -288,6 +312,10 @@ export function _generateBucketedConfig(
             continue
         }
 
+        const evalReason = featureOverride 
+            ? new EvalReason(EVAL_REASONS.OVERRIDE, EVAL_REASON_DETAILS.OVERRIDE)
+            : _getEvalReason(targetAndHashes!)
+
         featureKeyMap.set(
             feature.key,
             new SDKFeature(
@@ -297,7 +325,7 @@ export function _generateBucketedConfig(
                 variation._id,
                 variation.name,
                 variation.key,
-                null,
+                evalReason,
             ),
         )
         featureVariationMap.set(feature._id, variation._id)
@@ -321,8 +349,8 @@ export function _generateBucketedConfig(
                 variable.type,
                 variable.key,
                 variationVar.value,
-                null,
                 feature._id,
+                evalReason, 
             )
             variableMap.set(variable.key, newVar)
         }
@@ -340,9 +368,7 @@ export function _generateBucketedConfig(
 
 class BucketedVariableResponse {
     public variable: SDKVariable
-
     public variation: Variation
-
     public feature: Feature
 }
 
@@ -376,13 +402,15 @@ export function _generateBucketedVariableForUser(
         throw new Error('Internal error processing configuration')
     }
 
+    const evalReason = _getEvalReason(targetAndHashes)
+
     const sdkVar = new SDKVariable(
         variable._id,
         variable.type,
         variable.key,
         variationVar.value,
-        null,
         featureForVariable._id,
+        evalReason,
     )
     return { variable: sdkVar, variation, feature: featureForVariable }
 }
@@ -411,4 +439,4 @@ export function _getUserValueForBucketingKey(
         }
     }
     return user.user_id
-}
+}