[FSSDK-11466] Upgrade JS SDK version and modernize

.env.example

@@ -0,0 +1,10 @@
+# Optimizely SDK Configuration
+# Get your SDK key from the Optimizely dashboard: Settings > Environments
+OPTIMIZELY_SDK_KEY=your_optimizely_sdk_key
+
+# Optional: Set datafile cache TTL in seconds (default is 300 seconds / 5 minutes)
+# Example values: "300" (5 minutes), "600" (10 minutes), etc
+OPTIMIZELY_DATAFILE_CACHE_TTL_SECONDS="300"
+
+# Optional: Set log level for development (Error, Warn, Info, Debug)
+# LOG_LEVEL=Error

.gitignore

@@ -11,96 +11,41 @@ report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
 
 # Runtime data
 pids
-*.pid
-*.seed
-*.pid.lock
-
-# Directory for instrumented libs generated by jscoverage/JSCover
-lib-cov
-
-# Coverage directory used by tools like istanbul
-coverage
-*.lcov
-
-# nyc test coverage
-.nyc_output
-
-# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
-.grunt
-
-# Bower dependency directory (https://bower.io/)
-bower_components
-
-# node-waf configuration
-.lock-wscript
-
-# Compiled binary addons (https://nodejs.org/api/addons.html)
-build/Release
-
-# Dependency directories
+## Node / dependency folders
 node_modules/
-jspm_packages/
-
-# TypeScript v1 declaration files
-typings/
-
-# TypeScript cache
-*.tsbuildinfo
-
-# Optional npm cache directory
-.npm
-
-# Optional eslint cache
-.eslintcache
 
-# Microbundle cache
-.rpt2_cache/
-.rts2_cache_cjs/
-.rts2_cache_es/
-.rts2_cache_umd/
-
-# Optional REPL history
-.node_repl_history
-
-# Output of 'npm pack'
-*.tgz
-
-# Yarn Integrity file
-.yarn-integrity
+## Build / test output
+dist/
+coverage/
+.nyc_output/
+*.lcov
 
-# dotenv environment variables file
+## Environment files
 .env
 .env.test
 
-# parcel-bundler cache (https://parceljs.org/)
-.cache
+## Cloudflare Wrangler
+.wrangler/
 
-# Next.js build output
-.next
+## Logs
+logs
+*.log
 
-# Nuxt.js build / generate output
-.nuxt
-dist
+## Editor / OS files
+.DS_Store
+.vscode/
+thumbs.db
 
-# Gatsby files
+## Tool caches
 .cache/
-# Comment in the public line in if your project uses Gatsby and *not* Next.js
-# https://nextjs.org/blog/next-9-1#public-directory-support
-# public
-
-# vuepress build output
-.vuepress/dist
-
-# Serverless directories
-.serverless/
-
-# FuseBox cache
-.fusebox/
+.rpt2_cache/
 
-# DynamoDB Local files
-.dynamodb/
+## npm
+.npm
+.npmrc
 
-# TernJS port file
-.tern-port
+## Misc
+.node_repl_history
 
-worker
+## Distribution / packaging
+dist/

.vscode/extensions.json

@@ -0,0 +1,3 @@
+{
+	"recommendations": ["biomejs.biome"]
+}

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+	"cSpell.words": ["miniflare"]
+}

CHANGELOG.md

@@ -1,18 +1,63 @@
 # Change Log
+
 All notable changes to this project will be documented in this file.
- 
+
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
-
+
+## [1.0.0] - October 10, 2025
+
+### Changed
+
+- Updated `@optimizely/optimizely-sdk` to version `6.1.0` with ES modules support.
+- Migrated from addEventListener pattern to modern Cloudflare Workers fetch handler export syntax.
+- Replaced `uuid` package with native `crypto.randomUUID()` for user ID generation.
+- Replaced Webpack build with native ES modules.
+- Migrated configuration from `wrangler.toml` to `wrangler.jsonc`.
+- Refactored request handler to return standardized response format: `{statusCode: number, body: string, headers: Object}`.
+- Implemented graceful degradation: worker continues to function even if Optimizely initialization fails.
+- Enhanced error handling with try-catch blocks around all Optimizely operations - errors are logged but don't break the worker.
+- Added comprehensive JSDoc documentation throughout the codebase.
+- Improved datafile caching with module-scope cache and configurable TTL via `OPTIMIZELY_DATAFILE_CACHE_TTL_SECONDS` environment variable (default: 300 seconds).
+- Updated `cookie` package from `0.4.2` to `1.0.2`.
+- Migrated from Prettier to Biome for code formatting and linting.
+
+### Added
+
+- New `CloudflareRequestHandler` class implementing custom request handler for Cloudflare Workers environment.
+- New `getOptimizelyClient` helper function for centralized client management with smart caching.
+- New `getDatafile` helper function for fetching datafiles from Optimizely CDN.
+- Comprehensive unit test suite using Vitest and vitest-environment-miniflare.
+- Test files: `index.test.js`, `optimizely_helper.test.js`, `request_handler.test.js`.
+- Test utilities and setup files for easier testing.
+- `biome.jsonc` configuration for code quality tools.
+- `vitest.config.js` for test configuration.
+
+### Removed
+
+- Removed `uuid` package dependency (replaced with native Web Crypto API).
+- Removed Webpack build configuration (`webpack.config.js`).
+- Removed old `wrangler.toml` (replaced with `wrangler.jsonc`).
+- Removed Prettier in favor of Biome.
+
+### Fixed
+
+- Response body is now always returned as a string for consistent interface with Optimizely SDK expectations.
+- Worker no longer returns 500 errors on Optimizely failures; continues with degraded functionality.
+- Improved AbortError handling in request handler with proper error wrapping.
+
 ## [0.2.0] - April 4, 2022
 
 ### Added
+
 - Added cookie based user id memorization to support sticky [bucketing](https://docs.developers.optimizely.com/full-stack/v4.0/docs/how-bucketing-works).
 
 ### Changed
+
 - Updated `@optimizely/optimizely-sdk` version to `4.9.1`.
-  
+
 ## [0.1.0] - November 18, 2021
- 
+
 ### Added
+
 - First version of Cloudflare worker template with datafile caching and event dispatcher.

CONTRIBUTING.md

@@ -41,4 +41,4 @@ The YEAR above should be the year of the contribution. If work on the file has b
 
 ## Contact
 
-If you have questions, please contact [email protected].
+If you have questions, please contact [email protected].