@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.

[AviVahl]

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

[AviVahl]

@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.