Sameeran/ff 935 support for getparsedjsonassignment method (#13)

* Add getParsedJSONAssignment method and use in test

* Remove overly defensive optional chaining

* Increment version

* Test that overrides do not get logged

* Remove unused import

* Add test for new experiment key format

* Use td.reset so we can reuse the client between tests

* Clean up extra line

* Test logs variation assignment and experiment key

* wrap JSON stringify and parse with try catch

* Add deprecated comment

* Increment minor version

Author: sameerank

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@eppo/js-client-sdk-common",
-  "version": "1.4.1",
+  "version": "1.5.0",
   "description": "Eppo SDK for client-side JavaScript applications (base for both web and react native)",
   "main": "dist/index.js",
   "files": [

src/client/eppo-client.spec.ts

@@ -205,6 +205,11 @@ describe('EppoClient E2E test', () => {
             expect(stringAssignments).toEqual(expectedAssignments);
             break;
           }
+          case ValueTestType.JSONType: {
+            const jsonStringAssignments = assignments.map((a) => a?.stringValue ?? null);
+            expect(jsonStringAssignments).toEqual(expectedAssignments);
+            break;
+          }
         }
       },
     );
@@ -217,37 +222,51 @@ describe('EppoClient E2E test', () => {
   });
 
   it('returns subject from overrides when enabled is true', () => {
-    window.localStorage.setItem(
-      flagKey,
-      JSON.stringify({
-        ...mockExperimentConfig,
-        typedOverrides: {
-          '1b50f33aef8f681a13f623963da967ed': 'control',
-        },
-      }),
-    );
+    const entry = {
+      ...mockExperimentConfig,
+      enabled: false,
+      overrides: {
+        '1b50f33aef8f681a13f623963da967ed': 'override',
+      },
+      typedOverrides: {
+        '1b50f33aef8f681a13f623963da967ed': 'override',
+      },
+    };
+
+    storage.setEntries({ [flagKey]: entry });
+
     const client = new EppoClient(storage);
+    const mockLogger = td.object<IAssignmentLogger>();
+    client.setLogger(mockLogger);
+
     const assignment = client.getAssignment('subject-10', flagKey);
-    expect(assignment).toEqual('control');
+    expect(assignment).toEqual('override');
+    expect(td.explain(mockLogger.logAssignment).callCount).toEqual(0);
   });
 
   it('returns subject from overrides when enabled is false', () => {
     const entry = {
       ...mockExperimentConfig,
       enabled: false,
+      overrides: {
+        '1b50f33aef8f681a13f623963da967ed': 'override',
+      },
       typedOverrides: {
-        '1b50f33aef8f681a13f623963da967ed': 'control',
+        '1b50f33aef8f681a13f623963da967ed': 'override',
       },
     };
 
     storage.setEntries({ [flagKey]: entry });
 
     const client = new EppoClient(storage);
+    const mockLogger = td.object<IAssignmentLogger>();
+    client.setLogger(mockLogger);
     const assignment = client.getAssignment('subject-10', flagKey);
-    expect(assignment).toEqual('control');
+    expect(assignment).toEqual('override');
+    expect(td.explain(mockLogger.logAssignment).callCount).toEqual(0);
   });
 
-  it('logs variation assignment', () => {
+  it('logs variation assignment and experiment key', () => {
     const mockLogger = td.object<IAssignmentLogger>();
 
     storage.setEntries({ [flagKey]: mockExperimentConfig });
@@ -260,6 +279,13 @@ describe('EppoClient E2E test', () => {
     expect(assignment).toEqual('control');
     expect(td.explain(mockLogger.logAssignment).callCount).toEqual(1);
     expect(td.explain(mockLogger.logAssignment).calls[0].args[0].subject).toEqual('subject-10');
+    expect(td.explain(mockLogger.logAssignment).calls[0].args[0].featureFlag).toEqual(flagKey);
+    expect(td.explain(mockLogger.logAssignment).calls[0].args[0].experiment).toEqual(
+      `${flagKey}-${mockExperimentConfig.rules[0].allocationKey}`,
+    );
+    expect(td.explain(mockLogger.logAssignment).calls[0].args[0].allocation).toEqual(
+      `${mockExperimentConfig.rules[0].allocationKey}`,
+    );
   });
 
   it('handles logging exception', () => {
@@ -326,6 +352,12 @@ describe('EppoClient E2E test', () => {
           if (sa === null) return null;
           return EppoValue.String(sa);
         }
+        case ValueTestType.JSONType: {
+          const sa = globalClient.getJSONStringAssignment(subjectKey, experiment);
+          const oa = globalClient.getParsedJSONAssignment(subjectKey, experiment);
+          if (oa == null || sa === null) return null;
+          return EppoValue.JSON(sa, oa);
+        }
       }
     });
   }
@@ -368,6 +400,20 @@ describe('EppoClient E2E test', () => {
           if (sa === null) return null;
           return EppoValue.String(sa);
         }
+        case ValueTestType.JSONType: {
+          const sa = globalClient.getJSONStringAssignment(
+            subject.subjectKey,
+            experiment,
+            subject.subjectAttributes,
+          );
+          const oa = globalClient.getParsedJSONAssignment(
+            subject.subjectKey,
+            experiment,
+            subject.subjectAttributes,
+          );
+          if (oa == null || sa === null) return null;
+          return EppoValue.JSON(sa, oa);
+        }
       }
     });
   }
@@ -390,6 +436,9 @@ describe('EppoClient E2E test', () => {
       });
 
       it('overrides returned assignment', async () => {
+        const mockLogger = td.object<IAssignmentLogger>();
+        client.setLogger(mockLogger);
+        td.reset();
         const variation = await client.getAssignment(
           'subject-identifer',
           flagKey,
@@ -412,9 +461,13 @@ describe('EppoClient E2E test', () => {
         );
 
         expect(variation).toEqual('my-overridden-variation');
+        expect(td.explain(mockLogger.logAssignment).callCount).toEqual(0);
       });
 
       it('uses regular assignment logic if onPreAssignment returns null', async () => {
+        const mockLogger = td.object<IAssignmentLogger>();
+        client.setLogger(mockLogger);
+        td.reset();
         const variation = await client.getAssignment(
           'subject-identifer',
           flagKey,
@@ -436,6 +489,7 @@ describe('EppoClient E2E test', () => {
         );
 
         expect(variation).not.toEqual(null);
+        expect(td.explain(mockLogger.logAssignment).callCount).toEqual(1);
       });
     });
 

src/client/eppo-client.ts

@@ -69,7 +69,7 @@ export interface IEppoClient {
     assignmentHooks?: IAssignmentHooks,
   ): number | null;
 
-  getJSONAssignment(
+  getJSONStringAssignment(
     subjectKey: string,
     flagKey: string,
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
@@ -84,6 +84,7 @@ export default class EppoClient implements IEppoClient {
 
   constructor(private configurationStore: IConfigurationStore) {}
 
+  // @deprecated getAssignment is deprecated in favor of the typed get<Type>Assignment methods
   public getAssignment(
     subjectKey: string,
     flagKey: string,
@@ -92,13 +93,8 @@ export default class EppoClient implements IEppoClient {
     assignmentHooks?: IAssignmentHooks | undefined,
   ): string | null {
     return (
-      this.getAssignmentVariation(
-        subjectKey,
-        flagKey,
-        subjectAttributes,
-        assignmentHooks,
-        ValueType.StringType,
-      )?.stringValue ?? null
+      this.getAssignmentVariation(subjectKey, flagKey, subjectAttributes, assignmentHooks)
+        .stringValue ?? null
     );
   }
 
@@ -115,7 +111,7 @@ export default class EppoClient implements IEppoClient {
         subjectAttributes,
         assignmentHooks,
         ValueType.StringType,
-      )?.stringValue ?? null
+      ).stringValue ?? null
     );
   }
 
@@ -132,7 +128,7 @@ export default class EppoClient implements IEppoClient {
         subjectAttributes,
         assignmentHooks,
         ValueType.BoolType,
-      )?.boolValue ?? null
+      ).boolValue ?? null
     );
   }
 
@@ -149,11 +145,11 @@ export default class EppoClient implements IEppoClient {
         subjectAttributes,
         assignmentHooks,
         ValueType.NumericType,
-      )?.numericValue ?? null
+      ).numericValue ?? null
     );
   }
 
-  public getJSONAssignment(
+  public getJSONStringAssignment(
     subjectKey: string,
     flagKey: string,
     subjectAttributes: Record<string, EppoValue> = {},
@@ -165,8 +161,25 @@ export default class EppoClient implements IEppoClient {
         flagKey,
         subjectAttributes,
         assignmentHooks,
-        ValueType.StringType,
-      )?.stringValue ?? null
+        ValueType.JSONType,
+      ).stringValue ?? null
+    );
+  }
+
+  public getParsedJSONAssignment(
+    subjectKey: string,
+    flagKey: string,
+    subjectAttributes: Record<string, EppoValue> = {},
+    assignmentHooks?: IAssignmentHooks | undefined,
+  ): object | null {
+    return (
+      this.getAssignmentVariation(
+        subjectKey,
+        flagKey,
+        subjectAttributes,
+        assignmentHooks,
+        ValueType.JSONType,
+      ).objectValue ?? null
     );
   }
 
@@ -175,8 +188,8 @@ export default class EppoClient implements IEppoClient {
     flagKey: string,
     subjectAttributes: Record<string, EppoValue> = {},
     assignmentHooks: IAssignmentHooks | undefined,
-    valueType: ValueType,
-  ): EppoValue | null {
+    valueType?: ValueType,
+  ): EppoValue {
     const { allocationKey, assignment } = this.getAssignmentInternal(
       subjectKey,
       flagKey,
@@ -197,7 +210,7 @@ export default class EppoClient implements IEppoClient {
     flagKey: string,
     subjectAttributes = {},
     assignmentHooks: IAssignmentHooks | undefined,
-    valueType: ValueType,
+    expectedValueType?: ValueType,
   ): { allocationKey: string | null; assignment: EppoValue } {
     validateNotBlank(subjectKey, 'Invalid argument: subjectKey cannot be blank');
     validateNotBlank(flagKey, 'Invalid argument: flagKey cannot be blank');
@@ -208,11 +221,13 @@ export default class EppoClient implements IEppoClient {
     const allowListOverride = this.getSubjectVariationOverride(
       subjectKey,
       experimentConfig,
-      valueType,
+      expectedValueType,
     );
 
-    if (allowListOverride) {
-      if (!allowListOverride.isExpectedType()) return nullAssignment;
+    if (!allowListOverride.isNullType()) {
+      if (!allowListOverride.isExpectedType()) {
+        return nullAssignment;
+      }
       return { ...nullAssignment, assignment: allowListOverride };
     }
 
@@ -242,27 +257,16 @@ export default class EppoClient implements IEppoClient {
     const shard = getShard(`assignment-${subjectKey}-${flagKey}`, subjectShards);
     const assignedVariation = variations.find((variation) =>
       isShardInRange(shard, variation.shardRange),
-    )?.typedValue;
+    );
 
     const internalAssignment = {
       allocationKey: matchedRule.allocationKey,
-      assignment: EppoValue.Null(),
+      assignment: EppoValue.generateEppoValue(
+        expectedValueType,
+        assignedVariation?.value,
+        assignedVariation?.typedValue,
+      ),
     };
-
-    switch (valueType) {
-      case ValueType.BoolType:
-        internalAssignment['assignment'] = EppoValue.Bool(assignedVariation as boolean);
-        break;
-      case ValueType.NumericType:
-        internalAssignment['assignment'] = EppoValue.Numeric(assignedVariation as number);
-        break;
-      case ValueType.StringType:
-        internalAssignment['assignment'] = EppoValue.String(assignedVariation as string);
-        break;
-      default:
-        return nullAssignment;
-    }
-
     return internalAssignment.assignment.isExpectedType() ? internalAssignment : nullAssignment;
   }
 
@@ -314,25 +318,13 @@ export default class EppoClient implements IEppoClient {
   private getSubjectVariationOverride(
     subjectKey: string,
     experimentConfig: IExperimentConfiguration,
-    valueType: ValueType,
-  ): EppoValue | null {
+    expectedValueType?: ValueType,
+  ): EppoValue {
     const subjectHash = md5(subjectKey);
-    const overridden =
+    const override = experimentConfig?.overrides && experimentConfig.overrides[subjectHash];
+    const typedOverride =
       experimentConfig?.typedOverrides && experimentConfig.typedOverrides[subjectHash];
-    if (overridden) {
-      switch (valueType) {
-        case ValueType.BoolType:
-          return EppoValue.Bool(overridden as unknown as boolean);
-        case ValueType.NumericType:
-          return EppoValue.Numeric(overridden as unknown as number);
-        case ValueType.StringType:
-          return EppoValue.String(overridden as string);
-        default:
-          return null;
-      }
-    }
-
-    return null;
+    return EppoValue.generateEppoValue(expectedValueType, override, typedOverride);
   }
 
   /**

src/dto/experiment-configuration-dto.ts

@@ -5,7 +5,8 @@ export interface IExperimentConfiguration {
   name: string;
   enabled: boolean;
   subjectShards: number;
-  typedOverrides: Record<string, string>;
+  overrides: Record<string, string>;
+  typedOverrides: Record<string, number | boolean | string | object>;
   allocations: Record<string, IAllocation>;
   rules: IRule[];
 }

src/dto/variation-dto.ts

@@ -7,6 +7,7 @@ export interface IShardRange {
 
 export interface IVariation {
   name: string;
+  value: string;
   typedValue: IValue;
   shardRange: IShardRange;
 }