Parcel: unknown Statement of type "ForOfStatement"

[BobBuehler]

🐛 bug report

🎛 Configuration (.babelrc, package.json, cli command)

package.json

{
    "scripts": {
        "dev": "parcel ./src/index.html -d build/ --target=browser"
    }
}

.babelrc

{
    "presets": ["react"],
    "plugins": ["react-hot-loader/babel"]
}

🤔 Expected Behavior

It bundles and transpiles my es6 targetting node_module dependencies

😯 Current Behavior

regenerator-transform fails because it finds a for-of statement within a generator.

×  C:\git\my_webapp\node_modules\@private\core\dist\iterables.js: C:/git/my_webapp/node_modules/@private/core/dist/iterables.js: unknown Statement of type "ForOfStatement"
    at Emitter.Ep.explodeStatement (C:\git\my_webapp\node_modules\regenerator-transform\lib\emit.js:648:13)
    at C:\git\my_webapp\node_modules\regenerator-transform\lib\emit.js:344:12
    at Array.forEach (<anonymous>)
    at Emitter.Ep.explodeStatement (C:\git\my_webapp\node_modules\regenerator-transform\lib\emit.js:343:22)
    at Emitter.Ep.explode (C:\git\my_webapp\node_modules\regenerator-transform\lib\emit.js:298:40)
    at PluginPass.exit (C:\git\my_webapp\node_modules\regenerator-transform\lib\visit.js:122:15)
    at newFn (C:\git\my_webapp\node_modules\babel-traverse\lib\visitors.js:276:21)
    at NodePath._call (C:\git\my_webapp\node_modules\babel-traverse\lib\path\context.js:76:18)
    at NodePath.call (C:\git\my_webapp\node_modules\babel-traverse\lib\path\context.js:48:17)
    at NodePath.visit (C:\git\my_webapp\node_modules\babel-traverse\lib\path\context.js:117:8)

💁 Possible Solution

According to https://github.com/facebook/regenerator/issues/229 for-of statements need to be transformed before regenerator-transform can be applied. Maybe there is a way to force this.

🌍 Your Environment

| Software | Version(s) |
| ---------------- | ---------- |
| Parcel | 1.7.1 |
| Node | 9.11.1 |
| npm/Yarn | 1.6.0 |
| Operating System | Win 7 64bit |

[lbittner-pdftron]

Also getting this.. no other solutions posted anywhere work

[Offirmo]

[edited for clarification] I got this when migrating to babel 7. In the node_module which caused problem and which I own, I removed the .babelrc (which was no longer needed) and added the @babel/core: ^7 dependency and the error disappeared.

[devongovett]

Is anyone still having this issue? Sounds like possibly an issue in Babel rather than parcel itself?

[raine]

I start getting this in parcel v1.11.0 if I import p-memoize.

import pMemoize from 'p-memoize'

🚨  node_modules/map-age-cleaner/dist/index.js: unknown Statement of type "ForOfStatement"
    at Emitter.Ep.explodeStatement (node_modules/regenerator-transform/lib/emit.js:587:13)
    at node_modules/regenerator-transform/lib/emit.js:323:12
    at Array.forEach (<anonymous>)
    at Emitter.Ep.explodeStatement (node_modules/regenerator-transform/lib/emit.js:322:22)
    at Emitter.<anonymous> (node_modules/regenerator-transform/lib/emit.js:542:14)
    at LeapManager.LMp.withEntry (node_modules/regenerator-transform/lib/leap.js:143:14)
    at Emitter.Ep.explodeStatement (node_modules/regenerator-transform/lib/emit.js:541:24)
    at node_modules/regenerator-transform/lib/emit.js:323:12
    at Array.forEach (<anonymous>)
    at Emitter.Ep.explodeStatement (node_modules/regenerator-transform/lib/emit.js:322:22)

[mischnic]

Sounds like possibly an issue in Babel rather than parcel itself?

Well, Parcel doesn't transpile node_modules (neither with an option) and @babel/plugin-transform-regenerator can't handle for of.
In @raine's case and in an ideal world, https://www.npmjs.com/package/map-age-cleaner wouldn't use a for of loop.

[Offirmo]

@mischnic parced DOES transpile node_modules, provided the modules have a .babelrc

See my comment above.

[JoshyB]

Has anyone made any progress with this? I just started running into this last night and cannot figure out a solution. I am using Parcel-bundler as an express middleware and cannot get it to build at all.

node_modules/parcel-bundler/src/Bundler.js: unknown Statement of type "ForOfStatement"
    at Emitter.Ep.explodeStatement (node_modules/regenerator-transform/lib/emit.js:587:13)
    at node_modules/regenerator-transform/lib/emit.js:323:12
    at Array.forEach (<anonymous>)
    at Emitter.Ep.explodeStatement (node_modules/regenerator-transform/lib/emit.js:322:22)
    at Emitter.Ep.explodeStatement (node_modules/regenerator-transform/lib/emit.js:510:12)
    at node_modules/regenerator-transform/lib/emit.js:323:12
    at Array.forEach (<anonymous>)
    at Emitter.Ep.explodeStatement (node_modules/regenerator-transform/lib/emit.js:322:22)
    at Emitter.<anonymous> (node_modules/regenerator-transform/lib/emit.js:542:14)
    at LeapManager.LMp.withEntry (node_modules/regenerator-transform/lib/leap.js:143:14)
error Command failed with exit code 1.

[BobBuehler]

Closing was not what I meant to click. I'm surprised I had permission to do that. Sorry.

[Offirmo]

@JoshyB did my solution above help? https://github.com/parcel-bundler/parcel/issues/1269#issuecomment-427158354

[raine]

It had no effect for me.

[JoshyB]

@Offirmo I gave your solution a shot but it still wouldn't build. Same error.

[yuhr]

Same here, no one has resolved the issuee?

[yuhr]

I was facing into this error only when I use ipfs module, but FWIW now I found a workaround: in package.json setting like

  "browserslist": [
    "last 2 Chrome versions"
  ],

solved the issue for me (idea from https://github.com/ipfs/js-ipfs/blob/master/examples/browser-parceljs/package.json).

[pyros2097]

@yuhr Thanks ran into the same problem when using ipfs. Almost switched to webpack after seeing this https://github.com/orbitdb/example-orbitdb-todomvc-updated

[tehraven]

I was facing into this error only when I use ipfs module, but FWIW now I found a workaround: in package.json setting like

  "browserslist": [
    "last 2 Chrome versions"
  ],

solved the issue for me (idea from https://github.com/ipfs/js-ipfs/blob/master/examples/browser-parceljs/package.json).

This fixed my issue. Cheers.

[guillaumepotier]

@tehraven @yuhr may have fixed the issue, but the code you're shipping would not be supported by IE11. I'm still struggling with this problem, and I really need to support IE. Any help here?

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs.