Handle special characters when decoding obfuscated configurations (#187)

* make test output more helpful

* failing test

* use pure JS method

* bump version

* undo incorrect IDE suggestion for importing SparkMD5 as default

* feedback from PR

* fix linter issues

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@eppo/js-client-sdk-common",
-  "version": "4.7.0",
+  "version": "4.7.1",
   "description": "Common library for Eppo JavaScript SDKs (web, react native, and node)",
   "main": "dist/index.js",
   "files": [

src/configuration-requestor.ts

@@ -1,14 +1,7 @@
 import { IConfigurationStore } from './configuration-store/configuration-store';
 import { hydrateConfigurationStore } from './configuration-store/configuration-store-utils';
 import { IHttpClient } from './http-client';
-import {
-  BanditVariation,
-  BanditParameters,
-  Flag,
-  BanditReference,
-} from './interfaces';
-
-type Entry = Flag | BanditVariation[] | BanditParameters;
+import { BanditVariation, BanditParameters, Flag, BanditReference } from './interfaces';
 
 // Requests AND stores flag configurations
 export default class ConfigurationRequestor {
@@ -63,7 +56,8 @@ export default class ConfigurationRequestor {
             entries: banditResponse.bandits,
             environment: configResponse.environment,
             createdAt: configResponse.createdAt,
-            format: configResponse.format,});
+            format: configResponse.format,
+          });
 
           this.banditModelVersions = this.getLoadedBanditModelVersionsFromStore(
             this.banditModelConfigurationStore,

src/evaluator.ts

@@ -142,6 +142,7 @@ export class Evaluator {
         configDetails.configFormat,
       );
     } catch (err: any) {
+      console.error('>>>>', err);
       const flagEvaluationDetails = flagEvaluationDetailsBuilder.gracefulBuild(
         'ASSIGNMENT_ERROR',
         `Assignment Error: ${err.message}`,

src/events/default-event-dispatcher.spec.ts

@@ -12,6 +12,7 @@ global.fetch = jest.fn();
 
 const mockNetworkStatusListener = {
   isOffline: () => false,
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   onNetworkStatusChange: (_: (_: boolean) => void) => null as unknown as void,
 };
 
@@ -154,6 +155,7 @@ describe('DefaultEventDispatcher', () => {
   describe('offline handling', () => {
     it('skips delivery when offline', async () => {
       let isOffline = false;
+      // eslint-disable-next-line @typescript-eslint/no-unused-vars
       let cb = (_: boolean) => null as unknown as void;
       const networkStatusListener = {
         isOffline: () => isOffline,
@@ -188,6 +190,7 @@ describe('DefaultEventDispatcher', () => {
 
     it('resumes delivery when back online', async () => {
       let isOffline = true;
+      // eslint-disable-next-line @typescript-eslint/no-unused-vars
       let cb = (_: boolean) => null as unknown as void;
       const networkStatusListener = {
         isOffline: () => isOffline,

src/events/no-op-event-dispatcher.ts

@@ -2,6 +2,7 @@ import Event from './event';
 import EventDispatcher from './event-dispatcher';
 
 export default class NoOpEventDispatcher implements EventDispatcher {
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   dispatch(_: Event): void {
     // Do nothing
   }

src/flag-evaluation-details-builder.ts

@@ -11,7 +11,7 @@ export const flagEvaluationCodes = [
   'BANDIT_ERROR',
 ] as const;
 
-export type FlagEvaluationCode = typeof flagEvaluationCodes[number];
+export type FlagEvaluationCode = (typeof flagEvaluationCodes)[number];
 
 export enum AllocationEvaluationCode {
   UNEVALUATED = 'UNEVALUATED',

src/obfuscation.spec.ts

@@ -17,6 +17,17 @@ describe('obfuscation', () => {
     });
   });
 
+  it('encodes/decodes special characters', () => {
+    const strings = ['kümmert', 'піклуватися', '照顾', '🤗🌸'];
+
+    strings.forEach((string) => {
+      expect(decodeBase64(encodeBase64(string))).toEqual(string);
+      expect(decodeBase64(encodeBase64(string))).toEqual(string);
+    });
+
+    expect(decodeBase64('a8O8bW1lcnQ=')).toEqual('kümmert');
+  });
+
   describe('salt', () => {
     it('converts from bytes to base64 string', () => {
       const chars = new Uint8Array([101, 112, 112, 111]); // eppo

src/obfuscation.ts

@@ -8,11 +8,11 @@ export function getMD5Hash(input: string, salt = ''): string {
 }
 
 export function encodeBase64(input: string) {
-  return base64.btoaPolyfill(input);
+  return base64.encode(input);
 }
 
 export function decodeBase64(input: string) {
-  return base64.atobPolyfill(input);
+  return base64.decode(input);
 }
 
 export function obfuscatePrecomputedFlags(

test/testHelpers.ts

@@ -1,10 +1,10 @@
 import * as fs from 'fs';
 
-import { AttributeType, VariationType } from '../src';
-import { IAssignmentDetails } from '../src/client/eppo-client';
+import { isEqual } from 'lodash';
+
+import { AttributeType, ContextAttributes, IAssignmentDetails, VariationType } from '../src';
 import { IFlagEvaluationDetails } from '../src/flag-evaluation-details-builder';
 import { IBanditParametersResponse, IUniversalFlagConfigResponse } from '../src/http-client';
-import { ContextAttributes } from '../src/types';
 
 export const TEST_DATA_DIR = './test/data/ufc/';
 export const ASSIGNMENT_TEST_DATA_DIR = TEST_DATA_DIR + 'tests/';
@@ -125,16 +125,17 @@ export function validateTestAssignments(
   flag: string,
 ) {
   for (const { subject, assignment } of assignments) {
-    if (typeof assignment !== 'object') {
-      // the expect works well for objects, but this comparison does not
-      if (assignment !== subject.assignment) {
-        throw new Error(
-          `subject ${
-            subject.subjectKey
-          } was assigned ${assignment?.toString()} when expected ${subject.assignment?.toString()} for flag ${flag}`,
-        );
-      }
+    if (!isEqual(assignment, subject.assignment)) {
+      // More friendly error message
+      console.error(
+        `subject ${subject.subjectKey} was assigned ${JSON.stringify(
+          assignment,
+          undefined,
+          2,
+        )} when expected ${JSON.stringify(subject.assignment, undefined, 2)} for flag ${flag}`,
+      );
     }
-    expect(subject.assignment).toEqual(assignment);
+
+    expect(assignment).toEqual(subject.assignment);
   }
 }