Rollup-plugin-typescript2: This syntax requires an imported helper but module 'tslib' cannot be found.
I see that the code has some references to tslib and importHelpers so I assume this should work transparently. If not, I'll be happy to know what is missing.
Here is how to reproduce:
Installed packages:
$ npm ls --depth=0
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
└── [email protected]
tsconfig.json:
{
"compilerOptions": {
"target": "es5"
}
}
rollup.config.js:
import typescript from 'rollup-plugin-typescript2';
export default {
entry: './main.ts',
plugins: [
typescript()
]
}
main.ts:
import {Foo} from './module';
console.log("HERE" + Foo);
And module.ts:
export class Foo {}
export class Bar extends Foo {}
When running rollup as follows:
./node_modules/.bin/rollup -c rollup.config.js
I get this error:
🚨 rpt2: module.ts (3,18): semantic error TS2354 This syntax requires an imported helper but module 'tslib' cannot be found.
module.ts
I think this is because the extends syntax requires an __extends helper from tslib, but typescript can't find tslib.
Expected result is that the required helpers become part of the bundle.
Thanks.
bluetech
All 19 comments
This is definitely supposed to work transparently (and works for me in my own projects). I'll try your exact setup, thanks.
ezolenko
on 18 Apr 2017
Looks like you need "moduleResolution": "node" in tsconfig, otherwise typescript can't find tslib in node_modules.
Not sure if that could pose problems on non-node setups, but I haven't heard anything to that effect yet.
ezolenko
on 19 Apr 2017
Indeed, with "moduleResolution": "node", it works as expected. Reading https://www.typescriptlang.org/docs/handbook/module-resolution.html, I think "node" is a better fit for me, so I'll just use it. May I suggest mentioning/recommending it in the README?
I see that you opened #14 for the "classic" case, so I'll close this. Thanks!
bluetech
on 19 Apr 2017
Not sure anyone else facing the same problem as mine.
I was having this problem https://github.com/rollup/rollup-plugin-typescript/issues/109, therefore I switch to this repo, but then I'm getting this tslib error.
as the tsconfig is already "moduleResolution": "node"
hueitan
on 19 Sep 2019
If you post your tsconfig, rollup config and package.json, somebody might spot something amiss.
ezolenko
on 19 Sep 2019
@hueitan i faced the same issue while already having "moduleResolution": "node". Fixed it by adding "tslib": "^1.10.0" to my devDependencies.
giniedp
on 28 Sep 2019
adding tslib as the dependencies work to me as well. although not the pretty solution
hueitan
on 1 Oct 2019
tslib is already a dependency of rollup-plugin-typescript2, how does it end up missing on your system?
Do you use npm install or something else?
ezolenko
on 1 Oct 2019
in my case i am using yarn. Deleting the yarn.lock and reinstalling fresh, i do not need an explicit mention of tslib in the package.json
I can reproduce it in the following repo:
https://github.com/giniedp/tweak-ui
git clone [email protected]:giniedp/tweak-ui.git
cd tweak-ui
git checkout v0.1.0
now edit the package.json and remove tslib. Then do
yarn install
yarn run build
you should run into
This syntax requires an imported helper named '__spreadArrays', but module 'tslib' has no exported member '__spreadArrays'
now delete the yarn.lock and then
yarn install
yarn run build
runs fine.
giniedp
on 1 Oct 2019
This was fixed with this
@hueitan i faced the same issue while already having
"moduleResolution": "node". Fixed it by adding"tslib": "^1.10.0"to my devDependencies.
Fixed! Mine was in regular dependencies.
imnickvaughn
on 4 Oct 2019
Fixed it by adding "tslib": "^1.10.0" to my dependencies.
vishnu-85
on 19 Jan 2020
npm i tslib -D
worked for me too
Seanmclem
on 28 Apr 2020
Like @ezolenko says: While npm i tslib -D works, this should _not_ be used as the solution, because:
tslibis already a dependency ofrollup-plugin-typescript2, how does it end up missing on your system?Do you use
npm installor something else?
What worked in my case and is the better solution is to delete package-lock and node_modules and reinstall.
rm -rf ./node_modules
rm -rf ./package-lock.json
npm i
mesqueeb
on 17 May 2020
@hueitan i faced the same issue while already having
"moduleResolution": "node". Fixed it by adding"tslib": "^1.10.0"to my devDependencies.
Thank you, It's so helpful
Yangsou
on 21 May 2020
None of the proposed solutions worked for me. Upgrading rollup-plugin-typescript2 did the trick.
npm i [email protected]
It turns out rollup was using [email protected] even when I had ^1.10.0 in devDependencies. I realized rollup-plugin-typescript2 was overriding the tslib version. I was using v0.20.1; upgraded to v0.27.1.
caroso1222
on 7 Jul 2020
Weird behavior, But restarting VS code worked for me. I didn't have the issue previously, it just came up after doing an package install.
zimejin
on 19 Jul 2020
Fixed it by adding "tslib": "^1.10.0" to my dependencies.
Thanks. Just added to peerDependencies and it works well for me, do not need to install
irodger
on 30 Nov 2020
I had this error:
semantic error TS2343: This syntax requires an impor
ted helper named '__spreadArray' which does not exist in 'tslib'. Consider upgrading your version of 'tslib'.
Fixed it by adding "tslib": "^2.1.0" to my dependencies.
yehonadav
on 1 Apr 2021
You can simply upgrade our tslib version. I did mine from [email protected] to tslib@^2.2.0 which is the latest one by the time and it fixed my "__spreadArray" issue.
aman2talk
on 16 Apr 2021
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Most helpful comment
@hueitan i faced the same issue while already having
"moduleResolution": "node". Fixed it by adding"tslib": "^1.10.0"to my devDependencies.