cuid());\n \n return Response.json({ id, slug, isValid, isSlug, ids });\n }\n};","notes":"Collision-resistant ID generator. Creates sortable, URL-safe IDs. Includes cuid.slug() for shorter IDs and validation functions. Works on Workers with nodejs_compat.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-10","nodeCompat":true},"lastTested":"2026-01-13T18:36:00.000Z","testedBy":"manual","investigated":true},{"name":"d3-array","version":"3.2.4","weeklyDownloads":23436064,"status":"works","category":"utility","example":"import { min, max, mean, median, extent, group } from 'd3-array';\n\n// Usage:\nconst data = [1, 5, 2, 8, 3];\nconst minVal = min(data);\nconst maxVal = max(data);\nconst meanVal = mean(data);\nconst medianVal = median(data);\nconst extentVal = extent(data);\nconst grouped = group([{key: 'a', val: 1}, {key: 'b', val: 2}, {key: 'a', val: 3}], d => d.key);\nreturn { success: minVal === 1 && maxVal === 8 && meanVal === 3.8 && medianVal === 3, result: { minVal, maxVal, meanVal, medianVal, extentVal, grouped: grouped.size } };","notes":"D3 array manipulation library with statistical functions (min, max, mean, median), array transformations (group, bin, bisect), and data operations.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T22:29:48.522Z","testedBy":"automated"},{"name":"d3-scale","version":"4.0.2","weeklyDownloads":16890907,"status":"works","category":"utility","example":"import { scaleLinear, scaleLog, scalePow, scaleTime } from 'd3-scale';\n\n// Usage:\nconst linear = scaleLinear().domain([0, 10]).range([0, 100]);\nconst log = scaleLog().domain([1, 10]).range([0, 100]);\nconst pow = scalePow().exponent(2).domain([0, 10]).range([0, 100]);\nconst time = scaleTime().domain([new Date(2020, 0, 1), new Date(2021, 0, 1)]).range([0, 100]);\nconst linearVal = linear(5);\nconst logVal = log(5);\nconst powVal = pow(5);\nconst timeVal = time(new Date(2020, 6, 1));\nreturn { success: linearVal === 50 && logVal > 0 && powVal === 25 && timeVal > 0, result: { linearVal, logVal, powVal, timeVal } };","notes":"D3 scales for mapping data values to visual ranges. Includes linear, logarithmic, power, time, and categorical scales for data visualization.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T22:31:26.835Z","testedBy":"automated"},{"name":"d3-selection","version":"3.0.0","weeklyDownloads":9475891,"status":"not-applicable","category":"browser-framework","notes":"d3-selection is a D3.js library for data-driven DOM manipulation - selecting, modifying, and binding data to DOM elements (document.querySelector, element.appendChild, data binding with selection.data()). Requires browser APIs like document, window, HTMLElement, NodeList, and DOM tree manipulation which are not available in Workers' serverless environment. Designed exclusively for client-side browser-based data visualization and interactive DOM updates. Part of the D3.js ecosystem for creating dynamic, interactive visualizations in web browsers. For data visualization in Workers, use D3's non-DOM utilities (d3-array, d3-scale, d3-time, d3-format) for data processing and return data to client for rendering with D3.js, React, or other browser frameworks. Similar browser-only DOM manipulation libraries include jQuery, Zepto, cash-dom.","investigated":true,"testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T05:30:20.836Z","testedBy":"automated"},{"name":"d3-shape","version":"3.2.0","weeklyDownloads":20312077,"status":"works","category":"utility","example":"import { line, area, pie, arc } from 'd3-shape';\n\n// Usage:\nconst lineGenerator = line().x((d, i) => i * 10).y(d => d);\nconst linePath = lineGenerator([10, 20, 30, 20, 10]);\nconst areaGenerator = area().x((d, i) => i * 10).y0(0).y1(d => d);\nconst areaPath = areaGenerator([10, 20, 30, 20, 10]);\nconst pieGenerator = pie();\nconst pieData = pieGenerator([1, 2, 3]);\nconst arcGenerator = arc().innerRadius(0).outerRadius(100);\nconst arcPath = arcGenerator(pieData[0]);\nreturn { success: typeof linePath === 'string' && typeof areaPath === 'string' && pieData.length === 3 && typeof arcPath === 'string', result: { linePath: linePath.substring(0, 20), pieAngles: pieData.map(d => [d.startAngle, d.endAngle]) } };","notes":"D3 shape generators for SVG path data. Provides line(), area(), pie(), arc(), and more for creating data-driven shapes and charts.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T22:34:38.737Z","testedBy":"automated"},{"name":"datafire","version":"2.27.1","weeklyDownloads":114,"status":"not-applicable","category":"cli","notes":"DataFire is a CLI framework and API integration platform for building and hosting API workflows. Designed as a global CLI tool (npm install -g datafire) for creating projects that integrate with 1000+ APIs (AWS, Azure, MongoDB, Slack, GitHub, etc.). Actions can be triggered by URL, on a schedule, or manually. Requires filesystem access for project management, server infrastructure for running on ports, and the DataFire.io hosting platform for deployment. Similar API integration frameworks include Zapier, n8n, Node-RED. Not applicable to Workers which is a serverless HTTP runtime without CLI/project scaffolding capabilities.","errorMessage":"Cannot read properties of undefined (reading 'substring')","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T04:08:59.976Z","testedBy":"automated"},{"name":"date-fns","version":"4.1.0","weeklyDownloads":36195317,"status":"works","category":"date-time","example":"import { format, parseISO } from 'date-fns';\n\n// Usage:\nconst date = parseISO('2026-01-08');\nconst formatted = format(date, 'yyyy-MM-dd');\nreturn { success: formatted === '2026-01-08', result: formatted };","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-08T23:01:42.286Z","testedBy":"automated"},{"name":"dayjs","version":"1.11.19","weeklyDownloads":29726853,"status":"works","category":"date-time","example":"import dayjs from 'dayjs';\n\n// Usage:\nconst date = dayjs('2026-01-08');\nconst formatted = date.format('YYYY-MM-DD');\nreturn { success: formatted === '2026-01-08', result: formatted };","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-08T23:01:30.980Z","testedBy":"automated"},{"name":"deasync","version":"0.1.31","weeklyDownloads":390984,"status":"not-applicable","category":"native-module","notes":"deasync is a native C++ addon (uses node-gyp for compilation) that manipulates Node.js's event loop to turn async functions into synchronous ones via blocking operations. It requires compiling platform-specific native code and direct access to Node.js internals (libuv event loop) which are not available in Workers. Workers uses V8 isolates with a completely different execution model that doesn't support native addons or event loop blocking. Native modules require C++ bindings, node-gyp compilation, and OS-specific compiled binaries (.node files) which cannot run in Workers' sandboxed JavaScript-only runtime. For synchronous-looking code in Workers, use modern async/await syntax or top-level await in modules. Similar native modules that manipulate event loops include fibers, synchronize, sync-rpc.","investigated":true,"testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T05:03:24.219Z","testedBy":"automated"},{"name":"debounce","version":"3.0.0","weeklyDownloads":11611829,"status":"works","category":"async","example":"import debounce from 'debounce';\n\n// Usage:\nlet callCount = 0;\nconst debouncedFn = debounce(() => { callCount++; }, 100);\ndebouncedFn();\ndebouncedFn();\ndebouncedFn();\n// Wait for debounce delay\nawait new Promise(resolve => setTimeout(resolve, 150));\nreturn { success: callCount === 1, result: callCount };","notes":"Delays function calls until a set time elapses after the last invocation.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T22:39:09.569Z","testedBy":"automated"},{"name":"debug","version":"4.4.3","weeklyDownloads":392562383,"status":"works","category":"utility","example":"import debug from 'debug';\n\n// Create namespaced loggers\nconst logApp = debug('app:main');\nconst logHttp = debug('app:http');\n\n// Enable namespaces\ndebug.enable('app:*');\n\nexport default {\n async fetch(request) {\n const url = new URL(request.url);\n logApp('Request: %s %s', request.method, url.pathname);\n logHttp('Headers: %O', Object.fromEntries(request.headers));\n \n return Response.json({ debugEnabled: debug.enabled('app:main') });\n }\n};","notes":"Lightweight debugging utility with namespace-based logging. Works in Workers - debug output appears in console/logs.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-13T23:35:00.000Z","testedBy":"manual","investigated":true},{"name":"decamelize","version":"6.0.1","weeklyDownloads":38139427,"status":"works","category":"string","example":"import decamelize from 'decamelize';\n\n// Usage:\nconst result = decamelize('unicornRainbow');\nconst custom = decamelize('unicornRainbow', { separator: '-' });\nreturn { success: result === 'unicorn_rainbow' && custom === 'unicorn-rainbow', result: { result, custom } };","notes":"Converts camelCase strings to lowercase with custom separator (default underscore).","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T22:40:53.788Z","testedBy":"automated"},{"name":"decimal.js","version":"10.6.0","weeklyDownloads":30848538,"status":"works","category":"utility","example":"import Decimal from 'decimal.js';\n\n// Usage:\nconst x = new Decimal(0.1);\nconst y = new Decimal(0.2);\nconst result = x.plus(y).toString();\nreturn { success: result === '0.3', result };","notes":"Arbitrary-precision decimal arithmetic","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-10T06:30:11.164Z","testedBy":"automated"},{"name":"decompress","version":"4.2.1","weeklyDownloads":2654151,"status":"not-applicable","category":"dev-tool","notes":"decompress is a filesystem-based archive extraction library for extracting archives (zip, tar.gz, tar.bz2, etc.) to disk. Requires filesystem access to write extracted files to an output directory. The API takes a file path (string or Buffer) as input and an output directory path (string) as the second parameter: decompress('unicorn.zip', 'dist'). Workers is a stateless serverless environment without persistent filesystem access - files cannot be written to disk. This is designed for build-time/development workflows and local file extraction tasks, not for runtime use in Workers. For archive handling in Workers, use streaming APIs with libraries that work with Buffers/ArrayBuffers directly (e.g., jszip for zip files, fflate for compression), or return raw file data to client for extraction. Similar filesystem-based extraction tools include extract-zip, unzipper, tar-fs.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T06:13:56.353Z","testedBy":"automated"},{"name":"deep-diff","version":"1.0.2","weeklyDownloads":2120194,"status":"works","category":"utility","example":"import { diff, applyChange } from 'deep-diff';\n\n// Usage:\nconst lhs = { name: 'Alice', age: 30, city: 'NYC' };\nconst rhs = { name: 'Alice', age: 31, city: 'LA' };\nconst differences = diff(lhs, rhs);\nconst hasChanges = differences && differences.length === 2;\nconst ageChanged = differences.some(d => d.path[0] === 'age' && d.lhs === 30 && d.rhs === 31);\nconst cityChanged = differences.some(d => d.path[0] === 'city' && d.lhs === 'NYC' && d.rhs === 'LA');\nreturn { success: hasChanges && ageChanged && cityChanged, result: differences };","notes":"Calculate deep differences between objects. Captures changes (added, deleted, edited, array changes) and can apply/revert changes.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T22:43:50.320Z","testedBy":"automated"},{"name":"deep-equal","version":"2.2.3","weeklyDownloads":20172521,"status":"works","category":"utility","example":"import deepEqual from 'deep-equal';\n\n// Usage:\nconst result1 = deepEqual({ a: 1, b: { c: 2 } }, { a: 1, b: { c: 2 } });\nconst result2 = deepEqual({ a: 1 }, { a: 2 });\nreturn { success: result1 && !result2, result: { result1, result2 } };","notes":"Deep equality comparison for objects","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-10T06:30:35.022Z","testedBy":"automated"},{"name":"deep-extend","version":"0.6.0","weeklyDownloads":40313151,"status":"works","category":"utility","example":"import deepExtend from 'deep-extend';\n\n// Usage:\nconst result = deepExtend({ a: 1, b: { c: 2 } }, { b: { d: 3 } });\nreturn { success: result.a === 1 && result.b.c === 2 && result.b.d === 3, result };","notes":"Recursively extend objects","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-10T06:30:55.249Z","testedBy":"automated"},{"name":"deepmerge","version":"4.3.1","weeklyDownloads":47726009,"status":"works","category":"utility","example":"import deepmerge from 'deepmerge';\n\n// Usage:\nconst result = deepmerge({ a: 1, b: { c: 2 } }, { b: { d: 3 } });\nreturn { success: result.a === 1 && result.b.c === 2 && result.b.d === 3, result };","notes":"Deep merge of objects","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-10T06:32:14.701Z","testedBy":"automated"},{"name":"del","version":"8.0.1","weeklyDownloads":11287516,"status":"not-applicable","category":"dev-tool","notes":"del is a filesystem deletion utility for removing files and directories from disk (like rm -rf, rimraf). Used extensively in build scripts and development workflows (gulp tasks, cleanup scripts, pre-build cleaning) to delete build directories, temporary files, and old artifacts. Requires persistent filesystem access (fs.unlink, fs.rmdir) which is not available in Workers' stateless serverless environment. Workers has no persistent filesystem to delete from. Similar filesystem deletion tools include rimraf, fs-extra.remove(), graceful-fs. For cleanup tasks in Workers context, handle file operations in the build pipeline or use external storage services (R2, KV, Durable Objects). Original error was a module resolution issue with 'ignore' dependency.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T02:59:17.365Z","testedBy":"automated"},{"name":"depd","version":"2.0.0","weeklyDownloads":69104358,"status":"works","category":"utility","example":"import depd from 'depd';\n\nconst deprecate = depd('my-module');\n\nfunction oldFunction() {\n deprecate('oldFunction() is deprecated');\n return 'result';\n}\n\nexport default {\n async fetch(request) {\n const result = oldFunction();\n return Response.json({ result, message: 'Check console for deprecation warning' });\n }\n};","notes":"Deprecation warning utility for Node.js modules. Works in Workers for issuing console warnings about deprecated API usage.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-13T23:35:00.000Z","testedBy":"manual","investigated":true},{"name":"destroy","version":"1.2.0","weeklyDownloads":37606886,"status":"works","category":"utility","notes":"Destroy a stream safely, handling different stream types.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-10T06:32:49.921Z","testedBy":"manual-wrangler","investigated":true,"example":"import destroy from 'destroy';\nimport { Readable } from 'node:stream';\n\n// Usage:\nconst stream = new Readable({ read() {} });\ndestroy(stream);\nreturn { success: stream.destroyed, result: { destroyed: stream.destroyed } };"},{"name":"detect-port","version":"2.1.0","weeklyDownloads":5262020,"status":"not-applicable","category":"dev-tool","notes":"detect-port is a CLI/dev tool utility for finding available network ports on a local machine. It checks if a port is occupied and returns an available alternative port. Used extensively by development servers (webpack-dev-server, create-react-app, gatsby, storybook, vite, umi, flipper, micro) to automatically find free ports during local development. Requires network port binding via net.createServer() to test port availability and OS-level network APIs which are not available in Workers' serverless environment. Workers is an HTTP request/response runtime without access to network port binding or server lifecycle management. Similar port detection utilities include get-port, portfinder, port-scanner. Not applicable to Workers which doesn't have network server capabilities.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T05:05:10.497Z","testedBy":"automated"},{"name":"devalue","version":"5.6.1","weeklyDownloads":3398301,"status":"works","category":"utility","example":"import { stringify, parse } from 'devalue';\n\n// Usage:\nconst obj = { a: 1, b: new Date('2026-01-10'), c: /test/ };\nconst str = stringify(obj);\nconst result = parse(str);\nreturn { success: result.a === 1 && result.b instanceof Date, result };","notes":"Serialize JavaScript values (including Date, RegExp, Map, Set)","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-10T06:31:38.272Z","testedBy":"automated"},{"name":"diff","version":"8.0.2","weeklyDownloads":60704392,"status":"works","category":"utility","example":"import * as diff from 'diff';\n\n// Usage:\nconst result = diff.diffChars('hello', 'hallo');\nreturn { success: result.length > 0 && result.some(p => p.added || p.removed), result };","notes":"Text diff implementation (characters, words, lines, JSON)","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-10T06:33:01.056Z","testedBy":"automated"},{"name":"dinero.js","version":"1.9.1","weeklyDownloads":252901,"status":"works","category":"utility","example":"import Dinero from 'dinero.js';\n\n// Usage:\nconst price = Dinero({ amount: 500, currency: 'USD' });\nconst total = price.add(Dinero({ amount: 200, currency: 'USD' }));\nreturn { success: total.getAmount() === 700, result: total.toFormat('$0,0.00') };","notes":"Money/currency handling with precision","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-10T06:33:12.338Z","testedBy":"automated"},{"name":"discord.js","version":"14.25.1","weeklyDownloads":327396,"status":"use-alternative","category":"utility","notes":"discord.js is a Discord bot library that requires persistent WebSocket connections to Discord's Gateway API for real-time events (listening to messages, presence updates, voice state changes, etc.). Designed for long-running Node.js bot applications that maintain always-on Gateway connections. Workers is a stateless serverless environment without support for persistent WebSocket connections or long-running processes. The main discord.js package uses @discordjs/ws for Gateway WebSocket management which is incompatible with Workers' request/response lifecycle. Note: The discord.js website shows 'Powered by Cloudflare Workers' because their documentation site is hosted on Workers, not because the bot library works on Workers. For Discord interactions on Workers, use @discordjs/rest (REST API only) or @discordjs/core (thin wrapper for REST + webhook-based interactions). These packages support slash commands, webhooks, and REST API calls without requiring Gateway connections.","alternative":"@discordjs/rest or @discordjs/core for REST-only Discord interactions (slash commands, webhooks)","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T04:49:58.795Z","testedBy":"automated","investigated":true},{"name":"dockerode","version":"4.0.9","weeklyDownloads":2088808,"status":"not-applicable","category":"dev-tool","notes":"dockerode is a Docker Remote API client library for programmatic control of Docker containers, images, networks, and volumes. Requires network access to Docker daemon (unix socket or HTTP/TCP), filesystem operations for container tar archives (uses tar-fs for copying files to/from containers), and Docker daemon connectivity which doesn't exist in Workers' serverless environment. Designed for Docker automation, CI/CD pipelines, container orchestration, and development tooling that manage Docker infrastructure. Not applicable to Workers which is a stateless serverless HTTP runtime without access to Docker daemon or container management capabilities. Similar Docker client libraries include dockerode alternatives (dockerode-compose), Kubernetes clients (kubernetes-client), or container management SDKs.","errorMessage":"Package dockerode needs manual test configuration - do not use generic Object.keys() test","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T06:03:59.980Z","testedBy":"automated"},{"name":"dom-helpers","version":"6.0.1","weeklyDownloads":19549207,"status":"not-applicable","category":"browser-framework","notes":"Browser-only DOM manipulation library requiring DOM APIs (document, window, HTMLElement, classList, event handling, style manipulation, CSS classes). Used by react-bootstrap for cross-browser DOM utilities. Provides functions for addClass/removeClass, CSS styles, event handling, element dimensions (height/width), scroll position, and other DOM operations. Not applicable to Workers which is a serverless HTTP runtime without DOM APIs.","errorMessage":null,"testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T05:57:34.138Z","testedBy":"automated"},{"name":"dompurify","version":"3.3.1","weeklyDownloads":16647201,"status":"use-alternative","category":"security","alternative":"sanitize-html","notes":"DOMPurify requires a real DOM (window/document) which Workers doesn't have. isomorphic-dompurify also doesn't work (isSupported: false). Use sanitize-html instead - it's a pure string-based HTML sanitizer that works perfectly on Workers without DOM dependencies.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-10","nodeCompat":true},"lastTested":"2026-01-13T18:44:00.000Z","testedBy":"manual","investigated":true},{"name":"dotenv","version":"17.2.3","weeklyDownloads":73297109,"status":"not-applicable","category":"config","notes":"Not needed in Workers. Use environment bindings in wrangler.toml or dashboard instead of .env files.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T00:10:15.991Z","testedBy":"manual"},{"name":"dotenv-expand","version":"12.0.3","weeklyDownloads":21675175,"status":"not-applicable","category":"config-tool","notes":"Expands .env variables - use wrangler.toml for config in Workers","investigated":true,"testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-10T06:36:50.725Z","testedBy":"automated"},{"name":"download","version":"8.0.0","weeklyDownloads":1526206,"status":"not-applicable","category":"dev-tool","notes":"download is a filesystem-based HTTP file downloader for downloading and extracting files to disk. The API takes a URL and optional destination directory path (e.g., download('http://example.com/foo.jpg', 'dist')), downloads the file via HTTP/HTTPS, and writes it to the filesystem using fs.writeFileSync or createWriteStream. Supports extracting archives with the extract option using decompress to extract zip/tar files to disk. Requires persistent filesystem write access for saving downloaded files and stream piping to disk. Workers is a stateless serverless environment without persistent filesystem write access. For file downloads in Workers, fetch() data directly and return Response to client, or upload to R2 storage using env.R2_BUCKET.put(). Similar filesystem-based download utilities include node-fetch with fs.createWriteStream, axios with fs streams, got with pipe to filesystem.","errorMessage":"Cannot read properties of undefined (reading 'match')","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T04:34:58.322Z","testedBy":"automated"},{"name":"download-git-repo","version":"3.0.2","weeklyDownloads":81963,"status":"not-applicable","category":"dev-tool","notes":"download-git-repo is a CLI/dev tool for downloading and extracting git repositories from GitHub, GitLab, and Bitbucket to disk. Used in scaffolding tools (vue-cli, create-app, yeoman generators) for cloning starter templates and boilerplates during project initialization. Requires node:os module (not available in Workers), filesystem access to extract repository contents to local directories, and git protocol or HTTP download capabilities. Similar repository download tools include degit (lightweight git clone), giget (minimal git clone), download (HTTP file downloader), or git clone CLI. Not applicable to Workers which is a serverless HTTP runtime without filesystem access or project scaffolding capabilities.","errorMessage":"No such module \"node:os\".","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T03:10:33.851Z","testedBy":"automated"},{"name":"draft-js","version":"0.11.7","weeklyDownloads":867470,"status":"not-applicable","category":"browser-framework","notes":"Draft.js is a browser-only React framework for building rich text editors. Requires react-dom (peer dependency) for DOM manipulation APIs like document, window, HTMLElement, selection APIs, contentEditable, and DOM event handling. Provides Editor component that renders contentEditable , manages editor state with EditorState and ContentState, handles keyboard events and text input, supports rich text formatting (bold, italic, links, lists), block-level styling (headings, quotes), entity system for custom data, and decorator system for syntax highlighting. Used extensively in web applications for WYSIWYG editing (Facebook, Medium-style editors, comment systems, content management). Designed exclusively for browser environments with full DOM APIs. Not applicable to Workers which is a serverless HTTP runtime without DOM APIs. For rich text editing in Workers, return HTML/Markdown to client and use Draft.js in the browser application, or process rich text data structures (ContentState JSON) server-side for storage/rendering.","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T05:28:27.983Z","testedBy":"automated"},{"name":"drizzle-orm","version":"0.45.1","weeklyDownloads":3424449,"status":"works","category":"database","example":"import { sql } from 'drizzle-orm';\n\n// Usage:\nconst query = sql`SELECT * FROM users WHERE id = ${123}`;\nreturn { success: query.queryChunks.length > 0, result: 'SQL query built' };","notes":"TypeScript ORM with SQL-like syntax","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-10T06:40:40.149Z","testedBy":"automated"},{"name":"echarts","version":"6.0.0","weeklyDownloads":1456373,"status":"not-applicable","category":"ui","example":"import * as pkg from 'echarts';\n\n// Usage:\nconst keys = Object.keys(pkg);\nreturn { success: keys.length > 0, result: { exports: keys.slice(0, 5) } };","notes":"ECharts browser charting library - requires DOM","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T04:31:46.938Z","testedBy":"automated","investigated":true},{"name":"ejs","version":"3.1.10","weeklyDownloads":19966501,"status":"doesnt-work","category":"templating","notes":"EJS uses new Function() to compile templates at runtime, which is blocked in Workers for security. Pre-compile templates at build time or use edge-compatible alternatives like liquidjs or eta.","errorMessage":"Code generation from strings disallowed for this context","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T01:20:21.327Z","testedBy":"manual","alternative":"liquidjs, eta, or pre-compiled templates"},{"name":"elasticsearch","version":"16.7.3","weeklyDownloads":296894,"status":"use-alternative","category":"database","notes":"DEPRECATED package (no longer maintained since 2020). Official legacy Elasticsearch JavaScript client for connecting to Elasticsearch servers via HTTP REST API. Replaced by @elastic/elasticsearch (the new official client). The old client is no longer maintained and users are strongly advised to migrate to the new client. While theoretically an HTTP REST client could work in Workers, this legacy package is unmaintained and has compatibility issues. Original error 'Cannot read properties of undefined (reading 'bold')' occurred due to outdated dependencies and lack of maintenance.","alternative":"@elastic/elasticsearch (new official client) - may work with Workers, needs testing","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T04:37:12.850Z","testedBy":"automated","investigated":true},{"name":"electron","version":"unknown","weeklyDownloads":1729996,"status":"not-applicable","category":"desktop","example":"\n\n// Usage:\n","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T05:02:57.836Z","testedBy":"automated"},{"name":"element-ui","version":"2.15.14","weeklyDownloads":107446,"status":"not-applicable","category":"browser-framework","notes":"Browser-only Vue 2.x desktop component library. Provides UI components (buttons, forms, tables, dialogs, menus, date pickers, etc.) that require DOM APIs (document, window, HTMLElement) for rendering and user interaction. Designed exclusively for client-side browser environments with full DOM support. Element UI is the predecessor to Element Plus (Vue 3.x version). Not applicable to Workers which is a serverless HTTP runtime without DOM APIs.","errorMessage":"document is not defined","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T03:24:29.100Z","testedBy":"automated","investigated":true},{"name":"elliptic","version":"6.6.1","weeklyDownloads":10482180,"status":"use-alternative","category":"crypto","notes":"Pure JavaScript elliptic curve cryptography library for ECDSA, EdDSA, and ECDH operations. Supports curves: secp256k1, p192, p224, p256, p384, p521, curve25519, ed25519. Fails with 'Unexpected token \":\"' parse error when bundled for Workers - likely due to code incompatible with Workers runtime. Workers has the built-in Web Crypto API (crypto.subtle) which provides native elliptic curve cryptography (ECDSA with P-256/P-384/P-521, ECDH) with better performance and security than pure JavaScript implementations.","alternative":"Web Crypto API (crypto.subtle.sign/verify with ECDSA, crypto.subtle.deriveKey/deriveBits with ECDH) - built-in","errorMessage":"Unexpected token ':'","investigated":true,"testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T22:58:07.230Z","testedBy":"automated"},{"name":"email-validator","version":"2.0.4","weeklyDownloads":1119780,"status":"works","category":"validation","example":"import validator from 'email-validator';\n\n// Usage:\nconst valid = validator.validate('test@example.com');\nconst invalid = validator.validate('notanemail');\nreturn { success: valid && !invalid, result: { valid, invalid } };","notes":"Simple email validation","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-10T06:41:02.054Z","testedBy":"automated"},{"name":"ember-cli-babel","version":"8.2.0","weeklyDownloads":662071,"status":"not-applicable","category":"build-tool","notes":"ember-cli-babel is an Ember CLI plugin (build-time tool) that uses Babel and @babel/preset-env to transpile JavaScript code during the Ember CLI build process. It's configured in ember-cli-build.js as part of the Ember CLI build pipeline. Transpilation happens during development/build time, not at runtime. Similar build-time transpilation tools include babel-loader (webpack), @vitejs/plugin-react (vite), and other framework-specific Babel plugins. Not applicable to Workers which is a runtime environment, not a build tool. Modern bundlers (wrangler, webpack, vite, esbuild) handle JavaScript transpilation during the build step.","errorMessage":"Cannot read properties of undefined (reading 'length')","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T02:37:33.724Z","testedBy":"automated"},{"name":"ember-cli-htmlbars","version":"7.0.0","weeklyDownloads":424660,"status":"not-applicable","category":"build-tool","notes":"Ember CLI plugin (Broccoli plugin) for compiling Handlebars/HTMLBars templates during the Ember CLI build process. Provides custom AST transform registration and integrates with ember-template-compiler. Like all framework-specific build plugins (vue-loader for webpack, svelte-loader, @angular/compiler-cli), this is designed for development/build workflows, not runtime execution. Template compilation happens during the build step before deployment. Not applicable to Workers which is a runtime environment.","errorMessage":"Cannot read properties of undefined (reading 'native')","testedWith":{"wranglerVersion":"3.114.16","compatibilityDate":"2026-01-08","nodeCompat":true},"lastTested":"2026-01-09T03:09:04.897Z","testedBy":"automated"},{"name":"emotion","version":"11.0.0","weeklyDownloads":640636,"status":"not-applicable","category":"browser-framework","notes":"emotion is an older/deprecated CSS-in-JS library for styling React components (modern Emotion uses @emotion/react, @emotion/css, @emotion/styled instead). CSS-in-JS libraries like Emotion are designed for browser environments where they inject styles into the DOM via