Fun, full-featured, fully-local simulator for developing and testing Cloudflare Workers
See https://miniflare.dev for more detailed documentation.
- ๐จ Fetch Events (with HTTP server and manual triggering)
- โฐ Scheduled Events (with manual and cron triggering)
- ๐ Variables and Secrets with
.env
Files - ๐ Modules Support
- ๐ฆ KV (with optional persistence)
- โจ Cache (with optional persistence)
- ๐ Durable Objects (with optional persistence)
- ๐ Workers Sites
- โ๏ธ WebSockets
- ๐ Custom & Wrangler Builds Support
- โ๏ธ WebAssembly Support
- ๐บ Source Map Support
- ๐ธ Web Standards: Base64, Timers, Fetch, Encoding, URL, Streams, Crypto
- ๐ HTMLRewriter
- ๐ Automatic Reload on File Changes
- ๐ช Written in TypeScript
Miniflare is installed using npm:
$ npm install -g miniflare # either globally..
$ npm install -D miniflare # ...or as a dev dependency
$ miniflare worker.js --watch --debug
[mf:dbg] Options:
[mf:dbg] - Scripts: worker.js
[mf:dbg] Reloading worker.js...
[mf:inf] Worker reloaded!
[mf:dbg] Watching .env, worker.js, wrangler.toml...
[mf:inf] Listening on :8787
[mf:inf] - http://127.0.0.1:8787
import { Miniflare } from "miniflare";
const mf = new Miniflare({
script: `
addEventListener("fetch", (event) => {
event.respondWith(new Response("Hello Miniflare!"));
});
`,
});
const res = await mf.dispatchFetch("http://localhost:8787/");
console.log(await res.text()); // Hello Miniflare!
Usage: miniflare [script] [options]
Options:
-h, --help Show help [boolean]
-v, --version Show version number [boolean]
-H, --host HTTP server host to listen on (all by default)[string]
-p, --port HTTP server port (8787 by default) [number]
-d, --debug Log debug messages [boolean]
-c, --wrangler-config Path to wrangler.toml [string]
--wrangler-env Environment in wrangler.toml to use [string]
-m, --modules Enable modules [boolean]
--modules-rule Modules import rule (TYPE=GLOB) [array]
--build-command Command to build project [string]
--build-base-path Working directory for build command [string]
--build-watch-path Directory to watch for rebuilding on changes [string]
-w, --watch Watch files for changes [boolean]
-u, --upstream URL of upstream origin [string]
-t, --cron Cron pattern to trigger scheduled events with [array]
-k, --kv KV namespace to bind [array]
--kv-persist Path to persist KV data to (omit path for default)
--cache-persist Path to persist cached data to (omit path for default)
-s, --site Path to serve Workers Site files from [string]
--site-include Glob pattern of site files to serve [array]
--site-exclude Glob pattern of site files not to serve [array]
-o, --do Durable Object to bind (NAME=CLASS) [array]
--do-persist Path to persist Durable Object data to (omit path for
default)
-e, --env Path to .env file [string]
-b, --binding Bind variable/secret (KEY=VALUE) [array]
--wasm WASM module to bind (NAME=PATH) [array]
Many thanks to dollarshaveclub/cloudworker and gja/cloudflare-worker-local for inspiration.
Durable Object's transactions are implemented using Optimistic Concurrency Control (OCC) as described in "On optimistic methods for concurrency control." ACM Transactions on Database Systems. Thanks to Alistair O'Brien for helping me understand this.