Circular constraint reference in typings/utils.d.ts

Describe the bug We are migrating to Envelop and ran into a very odd error when trying to boot up.

node_modules/typescript/lib/lib.es5.d.ts:1553:11 - error TS2313: Type parameter 'P' has a circular constraint.

just for reference, this line is Pick

/**
 * From T, pick a set of properties whose keys are in the union K
 */
type Pick<T, K extends keyof T> = {
    [P in K]: T[P];
};

This was all the output and we began bashing our own code to try and find the error, finally after running tsc --build --verbose we got it to print the origin inside Envelop

node_modules/typescript/lib/lib.es5.d.ts:1553:11 - error TS2313: Type parameter 'P' has a circular constraint.
1553     [P in K]: T[P];
               ~

  node_modules/@envelop/types/utils.d.ts:13:93
    13 export declare type Spread<A extends readonly [...any]> = A extends [infer L, ...infer R] ? SpreadTwo<L, Spread<R>> : {};
                                                                                                   ~~~~~~~~~~~~~~~~~~~~~~~
    Circularity originates in type at this location.

for reference, it’s this line with references its own type Spread<A extends readonly [...any]> = A extends [infer L, ...infer R] ? SpreadTwo<L, Spread<R>> : {};

I’ve tried updating the line to

Spread<A extends readonly [...any]> = A extends [infer L, ...infer R] ? SpreadTwo<L,R> : {};

Which solved the issue on our codebase. Doing the same in envelop repo produces green tests and builds.

I can make a PR with this change but wanted to check first if it should be moved into its own type or what the purpose of it is.

To Reproduce To be fair, I don’t know how to reproduce it in Envelop repository, I’ve tried with --build --verbose and it does not give the same output. My colleague and I get the same error on our different machines with our codebase.

Expected behavior No typings errors

Environment:

• OS:
• "@envelop/core": “^1.4.0”,
• typescript tested on 4.3.4 and 4.5.4
• tsc-watch: “^4.2.8” for development mode
• NodeJS: 12.18.3, 14.17.3

Additional context We use a monorepo, each service have its own packages/typings

[dotansimha]

@Cuel I think this comes for a specific TypeScript setup you have in your project? (and I guess that’s why skipLibCheck: true solves that). The reason it’s using a circular definition is that we wanted to be able to recursively merge the context type when more than 2 types are used, so we “iterate” the array of types [infer L, ...infer R] and merge the with the previous type.

I wonder why it’s not emitting this error in our codebase - do you have a specific tsconfig configuration file that checks that? 🤔

@kamilkisiela thoughts?

[Cuel]

For now we can get around it with skipLibCheck: true in tsconfig.json