Typescript 4.7 with new moduleResolution mode node16/nodenext does not resolve types

[chrisui]

Current behavior

Types are not correctly resolved when using typescript 4.7 with moduleResolution set to "node16".

https://www.typescriptlang.org/docs/handbook/module-resolution.html

error TS2688: Cannot find type definition file for 'cypress'.

Desired behavior

Types should be resolved.

Test code to reproduce

{
  "compilerOptions": {
    "target": "ES2022",
    "lib": ["ES2022"],
    "skipLibCheck": true,
    "strict": true,
    "forceConsistentCasingInFileNames": true,
    "module": "node16",
    "moduleResolution": "node16",
    "allowJs": true,
    "resolveJsonModule": true,
    "isolatedModules": true,
    "esModuleInterop": true,
    "types": ["node", "cypress"]
  }
}

Cypress Version

10.1.0

Other

I believe this being due to new module resolution logic requiring explicit extension. Currently the package.json types field just says types (referring to the folder where historically it would've been inferred to use index.d.ts) but now needs to be explicit and configured as types/index.d.ts

[chrisui]

Validated that hacking the package.json to be explicit about file appears to solve this issue in my local project.

Ie. In package.json

From

"types": "types",

To

"types": "types/index.d.ts",

[smmccabe]

I get the same problem, but the above fix doesn't work. Also this isn't a problem with cypress v9, just with cypress v10, at least for me. I've been using nodenext since typescript 4.5 as experimental and it has always worked fine with cypress up until now.

[chrisui]

I may have jumped the gun on my fix that worked - possibly a version mismatch which would validate @smmccabe saying this has been a regression.

[lmiller1990]

Interesting, I will dig into this one tomorrow. One thing we changed from 9.x to 10.x was adding the exports field in package.json, I wonder if this is related?

https://github.com/cypress-io/cypress/blob/develop/cli/package.json#L119-L143

Thanks for the info @smmccabe, I'll verify on my end if it's a regression just to be sure - if so, that narrows the surface area down quite a bit, which is good.

[smmccabe]

You are correct, the exports need to also specify types, see microsoft/TypeScript#33079 and https://devblogs.microsoft.com/typescript/announcing-typescript-4-7-beta/#package-json-exports-imports-and-self-referencing

example:

    ".": {
      "import": "./index.mjs",
      "require": "./index.js",
      "types": "./types/index.d.ts"
    },

I hacked that in and it worked

[lmiller1990]

Nice job debugging this. Would you like to make a PR contributing a fix @smmccabe?

[smmccabe]

already made one just before you posted that :P

[louisscruz]

I think the blast radius of this issue might be larger than described here. I'm seeing the type issues mentioned above in TypeScript 4.5.2 in a Yarn PnP project. After "unplugging" and applying the fix from #22498, the issue goes away.