miniflare throws SyntaxError with module format worker configuration but works with wrangler

Hi,

I setup a module format worker using esbuild, and got it working using wrangler. However when I went to setup tests using miniflare the exact same configuration throws an error:

SyntaxError: Unexpected token 'export'

I have been bashing my head against it for a while, but cannot work out what the issue is. I created a minimal test repo to show the issue: https://github.com/autotelic/esm-wrangler-miniflare.git

All help gratefully received!

[eadmundo]

worked perfectly 😄 thanks so much @mrbbot (and also for everything you’ve done in developing miniflare, an amazing tool!)

[mrbbot]

Hey! 👋 Unlike Wrangler 2, Miniflare isn’t able to auto-detect you’re using a module format worker. You’ll need to add the --modules flag to your miniflare package.json script. Miniflare also doesn’t support the main field in wrangler.toml, but will read your main module from the module field in package.json (like Wrangler 1).

-  "main": "./dist/index.js",
+  "module": "./dist/index.js",
   "scripts": {
     "build": "esbuild --format=esm --bundle --sourcemap --outdir=dist ./src/index.js",
     "wrangler": "wrangler dev",
-    "miniflare": "miniflare"
+    "miniflare": "miniflare --modules"
   },