cloudflare/miniflare v2.0.0 on GitHub

Miniflare 2 has been completely redesigned from version 1 with 3 primary design goals:

📚 Modular: Miniflare 2 splits Workers components (KV, Durable Objects, etc.) into separate packages (@miniflare/kv, @miniflare/durable-objects, etc.) that you can import separately for testing.
✨ Lightweight: Miniflare 1 included 122 third-party packages with a total install size of 88MB. Miniflare 2 reduces this to 24 packages and 6MB by leveraging features included with Node.js 16.
✅ Accurate: Miniflare 2 more accurately replicates the quirks and thrown errors of the real Workers runtime, so you'll know before you deploy if things are going to break.

Check out the migration guide if you're upgrading from version 1.

Notable Changes

✳️ Node.js 16.7.0 is now the minimum required version
🤹 Added a custom Jest test environment, allowing you to run unit tests in the Miniflare sandbox, with isolated storage for each test
🔌 Added support for running multiple workers in the same Miniflare instance
⚡️ Added a live reload feature (--live-reload) that automatically refreshes your browser when your worker reloads
🚪 Added Durable Object input and output gates, and write coalescing
🛑 Added the DurableObjectState#blockConcurrencyWhile(callback) method
📅 Added support for compatibility dates and flags: durable_object_fetch_requires_full_url, fetch_refuses_unknown_protocols, formdata_parser_supports_files
📚 Added a proper CommonJS module loader
🗺 Automatically fetch the incoming Request#cf object from a trusted Cloudflare endpoint
🎲 Added support for crypto.randomUUID()
🔐 Added support for the NODE-ED25519 algorithm
✉️ Added support for sending/receiving binary WebSocket messages

Breaking Changes

Node.js 16.7.0 is now the minimum required version. You should use the latest Node.js version if possible, as Cloudflare Workers use a very up-to-date version of V8. Consider using a Node.js version manager such as https://volta.sh/ or https://github.com/nvm-sh/nvm.
Changed the storage format for Durable Objects and cached responses. If you're using file-system or Redis storage, you'll need to delete these directories/namespaces.
Changed the Durable Object ID format to include a hash of the object name. Durable Object IDs generated in Miniflare 1 cannot be used with Miniflare 2.
Correctly implement the Durable Object script_name option. In Miniflare 1, this incorrectly expected a script path instead of a script name. This now relies on mounting the other worker. See 📌 Durable Objects for more details.
Removed the non-standard DurableObjectStub#storage() method. To access Durable Object storage outside a worker, use the new Miniflare#getDurableObjectStorage(id) method, passing a DurableObjectId obtained from a stub. See 📌 Durable Objects for more details.
Renamed the --disable-cache/disableCache: true option to --no-cache/cache: false
Renamed the --disable-updater option to --no-update-check
When using the API, wrangler.toml, package.json and .env are no longer automatically loaded from their default locations. To re-enable this behaviour, set these options to true:
```
const mf = new Miniflare({
  wranglerConfigPath: true,
  packagePath: true,
  envPath: true,
});
```
Replaced the ConsoleLog class with the Log class from @miniflare/shared. You can construct this with a LogLevel to control how much information is logged to the console:
```
import { Miniflare, Log, LogLevel } from "miniflare";

const mf = new Miniflare({
  log: new Log(LogLevel.DEBUG),
});
```

Load WASM bindings from the standard wasm_modules wrangler.toml key instead of miniflare.wasm_bindings.

[miniflare]
wasm_bindings = [
  { name = "MODULE1", path="module1.wasm" },
  { name = "MODULE2", path="module2.wasm" }
]

...should now be...

[wasm_modules]
MODULE1 = "module1.wasm"
MODULE2 = "module2.wasm"

Renamed the buildWatchPath option to buildWatchPaths. This is now an array of string paths to watch as opposed to a single string.
Replaced the Miniflare#reloadOptions() method with the Miniflare#reload() and Miniflare#setOptions({ ... }) methods. reload() will reload options from wrangler.toml (useful if not watching), and setOptions() accepts the same options object as the new Miniflare constructor, applies those options, then reloads the worker.
Replaced the Miniflare#getCache() method the Miniflare#getCaches() method. This returns the global caches object. See ✨ Cache .
Miniflare#createServer() now always returns a Promise which you must await to get a http.Server/https.Server instance. You may want to check out the new Miniflare#startServer() method which automatically starts a server using the configured host and port.
Redis support is no longer included by default. If you're persisting KV, Durable Objects or cached responses in Redis, you must install the @miniflare/storage-redis optional peer dependency.
Replaced how Miniflare sanitises file paths for file-system storage so namespace separators (/, \, : and |) now create new directories.
The result of Miniflare#dispatchScheduled will no longer include undefined if a module scheduled handler doesn't return a value

Features and Fixes

Cache:

Added support for cf.cacheKey, cf.cacheTtl and cf.cacheTtlByStatus on Request. Closes issue #37, thanks @cdloh.
Added the CF-Cache-Status: HIT header to matched Responses
Log warning when trying to use cache with workers_dev = true in wrangler.toml. Cache operations are a no-op on workers.dev subdomains.
Throw errors when trying to cache Web Socket, non-GET, 206 Partial Content, or Vary: * responses
Throw an error when trying to open a cache with a name longer than 1024 characters

CLI:

Separated command line options into sections
Validate types of all command line options

Core:

Added support for running multiple workers in the same Miniflare instance. See 🔌 Multiple Workers for more details.
Added support for compatibility dates and flags, specifically the flags durable_object_fetch_requires_full_url, fetch_refuses_unknown_protocols, formdata_parser_supports_files are now supported. This feature is exposed under the --compat-date and --compat-flag CLI options, in addition to the standard keys in wrangler.toml. Closes issue #48, thanks @PaganMuffin. See 📅 Compatibility Dates for more details.
Added a proper CommonJS module loader. Workers built with Webpack will be more likely to work with Miniflare now. Closes issue #44, thanks @TimTinkers.
Don't crash on unhandled promise rejections when using the CLI. Instead, log them. Closes issue #115, thanks @togglydev.
Limit the number of subrequests to 50, as per the Workers runtime. Closes issue #117, thanks @leader22 for the suggestion.
To match the behaviour of the Workers runtime, some functionality, such as asynchronous I/O (fetch, Cache API, KV), timeouts (setTimeout, setInterval), and generating cryptographically-secure random values (crypto.getRandomValues, crypto.subtle.generateKey), can now only be performed while handling a request.
This behaviour can be disabled by setting the --global-async-io/globalAsyncIO, --global-timers/globalTimers and --global-random/globalRandom options respectively, which may be useful for tests or libraries that need async I/O for setup during local development. Note the Miniflare Jest environment automatically enables these options.
KV namespaces and caches returned from Miniflare#getKVNamespace() and getCaches() are unaffected by this change, so they can still be used in tests without setting any additional options.
To match the behaviour of the Workers runtime, Miniflare now enforces recursion depth limits. Durable Object fetches can recurse up to 16 times, and service bindings can recurse up to 32 times. This means if a Durable Object fetch triggers another Durable Object fetch, and so on 16 times, an error will be thrown.
Incoming request headers are now immutable. Closes issue #36, thanks @grahamlyons.
Disabled dynamic WebAssembly compilation in the Miniflare sandbox
Fixed instanceof on primitives such as Object, Array, Promise, etc. from outside the Miniflare sandbox. This makes it much easier to run Rust workers in Miniflare, as wasm-bindgen frequently generates this code.
Added a new --verbose/verbose: true option that enables verbose logging with more debugging information
Throw a more helpful error with suggested fixes when Miniflare can't find your worker's script
Only rebuild parts of the sandbox that need to change when options are updated

Added a new reload event to Miniflare instances that is dispatched whenever the worker reloads:

const mf = new Miniflare({ ... });
mf.addEventListener("reload", (event) => {
  console.log("Worker reloaded!");
});

Added a new Miniflare#getGlobalScope() method for getting the global scope of the Miniflare sandbox. This allows you to access and manipulate the Miniflare environment whilst your worker is running without reloading it. Closes issue #38, thanks @cdloh.
Added a new Miniflare#startScheduler() method that starts a CRON scheduler that dispatches scheduled events according to CRON expressions in options
Miniflare-added CF-* headers are now included in the HTML error response
Updated build script to use ES module exports of dependencies where possible. Thanks @lukeed for the PR.

Bindings:

Added --global KEY=VALUE/globals: { KEY: "value" } option for binding arbitrary values to the global scope. This behaves exactly like the --binding/bindings: { ... } option, but always binds to the global scope, even in modules mode.
Added a new global variable MINIFLARE to the Miniflare sandbox, which will always have the value true when your script is running within Miniflare
Miniflare now stringifies all environment variables from wrangler.toml. Closes issue #50, thanks @ozburo.
Adds highly experimental support for service bindings. This is primarily meant for internal testing, and users outside the beta can't deploy workers using this feature yet, but feel free to play around with them locally and let us know what you think in the Cloudflare Workers Discord server.
To enable these, mount your service (so Miniflare knows where to find it) then add the binding. Note the bound service name must match the mounted name:
```
$ miniflare --mount auth=./auth --service AUTH_SERVICE=auth # or -S
```
```
# wrangler.toml
experimental_services = [
  # Note environment is currently ignored
  { name = "AUTH_SERVICE", service = "auth", environment = "production" }
]

[miniflare.mounts]
auth = "./auth"
```
```
const mf = new Miniflare({
  mounts: { auth: "./auth" },
  serviceBindings: { AUTH_SERVICE: "auth" },
});
```
...then to use the service binding:
```
export default {
  async fetch(request, env, ctx) {
    const res = await env.AUTH_SERVICE.fetch("...");
    // ...
  },
};
```
If ./auth/wrangler.toml contains its own service bindings, those services must also be mounted in the root worker (i.e. in wrangler.toml not ./auth/wrangler.toml). Nested mounts are not supported.

Builds:

When running your worker's build script, Miniflare will set the environment variable MINIFLARE=1. Closes issue #65, thanks @maraisr.
Added an alias, -B, for the --build-command option
Multiple build watch paths can now be specified. If any of them change, your worker will rebuild and reload.
Pass the --env flag to wrangler build when --wrangler-env is set for type = "webpack"/"rust" builds
Fixed an issue where workers would not rebuild if the build watch path started with ./. Closes issue #53, thanks @janat08.

Standards:

Added support for crypto.randomUUID()
Added support for structuredClone. Note the transfer option is only supported on Node.js >= 17.
Added support for queueMicrotask
Added support for the NODE-ED25519 algorithm to crypto.subtle.sign() and crypto.subtle.verify()
Added support for AbortSignal.timeout()
Added support for crypto.DigestStream
Added support for scheduler.wait()
Added support for FixedLengthStream. Closes issue #123, thanks @vlovich.
Throw an error when attempting to create a new TextDecoder with a non-UTF-8 encoding
Throw errors when attempting to use FetchEvent/ScheduledEvent methods with incorrectly bound this
Throw errors when attempting to call respondWith() twice, or after the fetch handler has finished executing synchronously. Closes issue #63, thanks @Kikobeats.
Added support for the unhandledrejection and rejectionhandled events
Throw an error (with a suggested fix) when trying to access an env binding globally in modules mode
Throw errors when trying to use addEventListener(), removeEventListener() and dispatchEvent() globals in modules mode
Split the FetchError: No fetch handler responded and unable to proxy request to upstream? error into more specific errors with suggested fixes
Added the non-standard Headers#getAll() method. This can only be used with the Set-Cookie header.
Switch to a more spec-compliant fetch implementation, and get crypto, EventTarget and Web Streams from Node.js. Closes issues #56 and #59, thanks @jasnell, @jonathannorris and @SupremeTechnopriest.
Added support for the Response#encodeBody property. If this is omitted or set to auto, Responses with a Content-Encoding header that includes gzip, deflate or br will be automatically encoded. Closes issue #72, thanks @SupremeTechnopriest.
Return a non-opaque Response containing headers when fetching with a redirect mode set to manual in response to a redirect, closes issue #133, thanks @hansede, @vzaramel and @hnrqer.
Set the redirect mode of incoming requests to manual, matching the behaviour of the Workers runtime
Remove extra headers not sent by Cloudflare Workers with fetch requests. Closes issue #139, thanks @dfcowell.
Request/Response bodys are now byte streams, allowing them to be read with bring-your-own-buffer readers
Throw an error when attempting to construct a WebSocket response with a status other than 101
Throw an error when attempting to clone a WebSocket response
Added support for the non-standard ReadableStreamBYOBReader#readAtLeast(size, buffer) method
Include File in the Miniflare sandbox. Closes issue #66, thanks @tranzium.

Durable Objects:

Added input and output gates for ensuring consistency without explicit transactions
Added write coalescing for put/delete without interleaving awaits for automatic atomic writes
Added the DurableObjectState#blockConcurrencyWhile(callback) method. This prevents new fetch events being delivered to your object whilst the callback runs. Closes issue #45, thanks @gmencz.
Added the DurableObjectId#equals(id) method for comparing if 2 Durable Object IDs have the same hex-ID
Automatically resolve relative URLs passed to DurableObjectStub#fetch(input, init?) against https://fast-host. Closes issue #27, thanks @halzy.
Throw an error if the string passed to DurableObjectNamespace#idFromString(hexId) is not 64 hex digits
Throw an error if the hex-ID passed to DurableObjectNamespace#idFromString(hexId) is for a different Durable Object
Throw an error if the ID passed to DurableObjectNamespace#get(id) is for a different Durable Object
Throw an error when keys are greater than 2KiB or undefined
Throw an error when values are greater than 128KiB
Throw an error when attempting to get, put or delete more than 128 keys, or when attempting to modify more than 128 keys in a transaction
Throw an error when attempting to put an undefined value
Throw an error when attempting to list keys with a negative limit
Throw an error when attempting to perform an operation in a rolledback transaction or in a transaction that has already committed
Throw an error when attempting to call deleteAll() in a transaction
Throw an error when a Durable Object fetch handler doesn't return a Response
Use the same V8 serialization as Cloudflare Workers to store values
Fixed an issue where keys added in a transaction callback were not reported as deleted in the same transaction
Fixed an issue where keys added in a transaction callback were not included in the list of keys in the same transaction

HTMLRewriter:

Remove Content-Length header from HTMLRewriter transformed Responses
Don't start transforming until transformed Response body is needed
Throw an error when attempting to transform body streams containing non-ArrayBuffer/ArrayBufferView chunks

HTTP Server:

Added a live reload feature, that automatically refreshes your browser when your worker reloads. For this to work, pass the --live-reload option, and return an HTML response containing a <body> tag with the Content-Type set to text/html. See ⚡️ Live Reload for more details.

addEventListener("fetch", (event) => {
  const body = `
    <!DOCTYPE html>
    <html>
    <body>
      <p>Try update me!</p>
    </body>
    </html>
  `;

  const res = new Response(body, {
    headers: { "Content-Type": "text/html; charset=utf-8" },
  });

  event.respondWith(res);
});

Added --open/-O option that automatically opens your browser once your worker is running. You can optionally specify a different URL to open with --open https://example.com. Closes issue #121, thanks @third774 for the suggestion.
Automatically fetch the incoming Request#cf object from a trusted Cloudflare endpoint, so the values are the same as you'd get for real. Closes issue #61, thanks @aaronsdevera and @Electroid.

Added a metaProvider option that allows you fetch metadata for an incoming Request:

const mf = new Miniflare({
  async metaProvider(req) {
    return {
      forwardedProto: req.headers["X-Forwarded-Proto"],
      realIp: req.headers["X-Forwarded-For"],
      cf: {
        // Could get these from a geo-IP database
        colo: "SFO",
        country: "US",
        // ...
      },
    };
  },
});

Split out the Node request to Request object conversion logic into a convertNodeRequest(req, meta?) function. You can import this from @miniflare/http-server.
Only return a pretty-error page when the request Accept header includes text/html
Added a new Miniflare#startServer(options?) method that starts an HTTP server using the configured port and host. options can be a http.ServerOptions or https.ServerOptions object. Closes issue #39, thanks @amlwwalker
Include a default Content-Type header of text/plain in Responses. Closes issue #57, thanks @Rysertio.

Jest Environment:

Added a custom Jest test environment, allowing you to run unit tests in the Miniflare sandbox, with isolated storage for each test. See 🤹 Jest Environment for more details.

KV:

Throw an error when keys are empty, ., .., undefined, or greater than 512B when UTF-8 encoded
Throw an error when values are greater than 25MiB
Throw an error when metadata is greater than 1KiB
Throw an error when the cacheTtl option is less than 60s
Throw an error when expirationTtl is non-numeric, less than or equal 0, or less than 60s
Throw an error when expiration is non-numeric, less than or equal the current time, or less than 60s in the future
Throw an error when the limit passed to KVNamespace#list() is non-numeric, less than or equal 0, or greater than 1000

Scheduler:

Moved the /.mf/scheduled endpoint for triggering scheduled events to /cdn-cgi/mf/scheduled. Closes issue #42, thanks @ObsidianMinor.
Switched the CRON validation and scheduling package from node-cron to cron-schedule. This improves error messages for invalid CRON expressions, and removes a transitive dependency on moment-timezone, reducing the installation size by 5MB.

Workers Sites:

Added support for the new __STATIC_CONTENT_MANIFEST text module allowing you to use Workers Sites in modules mode

Web Sockets:

Added support for sending/receiving binary messages. Closes issue #67, thanks @NostalgiaRunner.
Removed the WebSocket#readyState property. Closes issue #47, thanks @aboodman.
Wait for worker response before opening WebSocket in client, closes issue #88, thanks @TimTinkers.
http and https protocols are now required for WebSocket upgrades via fetch as per the workers runtime
Throw an error when attempting to use a WebSocket in a Response that has already been used
Throw an error when attempting to use a WebSocket in a Response after calling accept() on it
Throw an error when attempting to construct a WebSocket using the WebSocket constructor
Throw an error when attempting to call WebSocket#send() or WebSocket#close() without first calling accept(). Closes issue #43, thanks @aboodman.
Throw an error when attempting to call WebSocket#send() after calling close()
Throw an error when attempting to call WebSocket#close() on an already closed WebSocket
Throw an error when attempting to call WebSocket#close() with an invalid close code
Make WebSocket event constructors more spec-compliant

Changes Since `2.0.0-rc.5`

Return a Response containing headers when fetching with a redirect mode set to manual in response to a redirect, closes issue #133, thanks @hansede, @vzaramel and @hnrqer.
Set the redirect mode of incoming requests to manual, matching the behaviour of the Workers runtime
Removed default fetch headers automatically added by undici, closes issue #139, thanks @dfcowell
Removed the --proxy-primitive/proxy_primitive_instanceof option. This is now the default behaviour, whilst still allowing prototype/constructor checks to succeed. See 🕸 Web Standards for more details.

cloudflare/miniflare v2.0.0 on GitHub

Notable Changes

Breaking Changes

Features and Fixes

Changes Since 2.0.0-rc.5

cloudflare/miniflare v2.0.0
on GitHub

Changes Since `2.0.0-rc.5`