TypeScript build errors

[kamilmielnik]

When using node-fetch-cjs as a dependency in a TypeScript project, I get the following errors during compilation:

> tsc --project .

node_modules/node-fetch-cjs/dist/index.d.ts:4:24 - error TS2307: Cannot find module 'formdata-polyfill/esm.min.js' or its corresponding type declarations.

4 import {FormData} from 'formdata-polyfill/esm.min.js';
                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

node_modules/node-fetch-cjs/dist/index.d.ts:12:8 - error TS2307: Cannot find module 'fetch-blob/from.js' or its corresponding type declarations.

12 } from 'fetch-blob/from.js';
          ~~~~~~~~~~~~~~~~~~~~

node_modules/node-fetch-cjs/dist/index.d.ts:24:2 - error TS2323: Cannot redeclare exported variable 'FormData'.

24  FormData,
    ~~~~~~~~

node_modules/node-fetch-cjs/dist/index.d.ts:25:2 - error TS2323: Cannot redeclare exported variable 'Blob'.

25  Blob,
    ~~~~

node_modules/node-fetch-cjs/dist/index.d.ts:221:14 - error TS2323: Cannot redeclare exported variable 'Blob'.

221 export const Blob: typeof globalThis.Blob;
                 ~~~~

node_modules/node-fetch-cjs/dist/index.d.ts:223:22 - error TS2323: Cannot redeclare exported variable 'FormData'.

223 export declare const FormData: { new (): FormData; prototype: FormData; };
                         ~~~~~~~~


Found 6 errors in the same file, starting at: node_modules/node-fetch-cjs/dist/index.d.ts:4

The workaround for this is to set skipLibCheck to true in tsconfig.json:

  "skipLibCheck": true,

Unfortunately this workaround "pollutes" the dependency chain, i.e. any package that uses a package that uses node-fetch-cjs will have to do this.

[kamilmielnik]

The workaround for this is to set skipLibCheck to true in tsconfig.json:

Another workaround (which I ended up going with) is to use patch-package and adjust the types manually: https://github.com/limesquid/favicon-thief/pull/18/files#diff-19296082039c0cf585632cd8d284d6470b79e98f67c3ff42643c0333010ceae3R1.
This way there's no need to use skipLibCheck: true.