[Bug] TS2742 The inferred type of … cannot be named without a reference to …

[bradleyayers]

Describe the bug

When using pnpify, ttypescript, and yarn workspaces, trying to compile (pnpify ttsc -b -p tsconfig.json) one of my workspaces I receive numerous TS2742 errors, one example is:

src/routing/RoutingContext.tsx:21:14 - error TS2742: The inferred type of 'RoutingContext' cannot be named without a reference to '../../../../.yarn/cache/@types-prop-types-npm-15.5.5-d376afe0878cf73ef7826a6fbbde3b8bbd763fa63a05ffcc0b452aaca80cefd1.zip/node_modules/@types/prop-types/node_modules/@types/react'. This is likely not portable. A type annotation is necessary.

In one of my workspaces there's 20 of these, so I could go around and actually add type annotations to these, but it would be a regression in developer experience to have to do this. Looks potentially related to microsoft/TypeScript#29221

To Reproduce

Not sure what the minimal reproduction is, I can do more investigation if this issue is foreign and needs more explanation.

Environment if relevant (please complete the following information):

• OS: OSX
• Node version 10.9.0
• TypeScript 3.5.1
• Yarn version 2

Additional context

[bradleyayers]

Turns out this was due to React not being imported in the files, yet was seemingly made available globally implicitly. Adding import React from "react"; to the top of problematic files fixed this.

[bradleyayers]

There was actually another set of these errors that came from having two versions of @types/react installed. I think a second version was pulled in via transitive dependency so adding a "@types/react": "^16.8.19", to my root workspace resolutions fixed it.

[flyskywhy]

I solved it by move project position to a clean folder which has no parent node_modules/. For example, if

npm install @textile/js-http-client
cd node_modules/@textile/js-http-client/
npm install
./node_modules/.bin/tsc

will get error:

src/modules/account.ts:53:3 - error TS2742: The inferred type of 'sync' cannot be named without a reference to '@textile/js-http-client/node_modules/web-streams-polyfill'. This is likely not portable. A type annotation is necessary.

53   sync(apply?: boolean, wait?: number) {

but if

mv node_modules/@textile/js-http-client/ ../
cd ../js-http-client/
npm install
./node_modules/.bin/tsc

everything is OK.

[anupam-io]

Happened because not defineing the return type of an async function. I defined the return type as Promise<any>, and the error went away.

[marek-hanzal]

I've encountered the same problem (it's not related to this issue), but may help: I do not want to put dummy imports around the files, so I've tried to add just types to tsconfig.json aaaaaand! It helped!

[InfiniteXyy]

I also encountered this problem in monorepo. My solution is to remove the exclude: ["node_modules"] in the public pacakge.

[marek-hanzal]

I've another note on the topic: I've removed PNPM and used just NPM in the cost of less obvious phantom package detection (but lint covers this). 99% of TS problems dissapeared when I've switch to NPM (or maybe YARN).