yargs: @types/typescript does not work with `import` syntax

Reproduce by running the following in an empty directory:

npm init
npm i yargs
echo "import yargs from 'yargs';" > index.ts
tsc index.ts

We get the error

index.ts:1:19 - error TS2307: Cannot find module 'yargs' or its corresponding type declarations.

1 import yargs from 'yargs'
                    ~~~~~~~


Found 1 error.

Reproduced with yargs 16.0.3 and tsc 4.0.2.

About this issue

Original URL
State: closed
Created 4 years ago
Comments: 15 (6 by maintainers)

Most upvoted comments

https://github.com/yargs/yargs#typescript yargs doesn’t ship built-in types yet, so one has to install @types/yargs as well.

AviVahl on Sep 10, 2020

@bcoe you can already import yargs as 'yargs'; if you have esModuleInterop turned on (default in tsc --init) and @types/yargs in place. We do so in stylable: https://github.com/wix/stylable/blob/master/packages/cli/src/cli.ts

We are getting yargs in its require form though, as our modules transpile to commonjs (meaning a require('yargs') is being called).

EDIT: just to clarify… esModuleInterop causes allowSyntheticDefaultImports to be turned on, which causes the type checker to allow importing “commonjs modules” (.d.ts says export =) using default import.

AviVahl on Sep 10, 2020

I apologize for the confusion it created having this briefly work in v15. We do not intend to ship TypeScript definitions in yargs or yargs-parser in the near future.

Here’s a post on the topic.

@types/yargs is well supported and used widely by the community, but deviates sigificantly from the actual TypeScript API surface of the library.

Basically, we had the choice break TypeScript for 1000s of existing libraries, or ship without types ourselves… I think this is the right call.

The other problem with shipping the library itself with the types is that breaking changes to types vs the API surface become indistinguishable.

bcoe on Sep 10, 2020