Maximum call stack size exceeded when emitting declaration file that should reference an unnameable infinite conditional type

[bluepichu]

Bug Report

🔎 Search Terms

maximum call stack size exceeded, declaration emit, unnameable, unnamable, unexported, infinite conditional type

🕗 Version & Regression Information

Crash on 4.2.4, 4.3.0-beta, 4.4.0-dev.20210523

⏯ Repo Link

https://github.com/bluepichu/typescript-issue-44225

(Can't use the playground since this requires multiple files.)

💻 Code

// a.ts

type TupleIntersection<T extends unknown[]> =
	T extends [] ? unknown :
	T extends [infer Hd, ...infer Tl] ? Hd & TupleIntersection<Tl> :
	never;

export const intersectionCheck =
	<Types extends unknown[] = []>() =>
		<Intersection extends TupleIntersection<Types>>(obj: Intersection) => obj;

// b.ts

import { intersectionCheck } from "./a";

export const intersectionCheckWrapper =
	<Types extends unknown[] = []>() =>
		<Obj>(obj: Obj) => intersectionCheck<Types>()(obj);

Note: this only occurs with declaration emit enabled (since it's a crash in declaration emit), and only when TupleIntersection is not exported (see "workaround" below).

🙁 Actual behavior

Crash during declaration emit:

/Users/bluepichu/.config/yarn/global/node_modules/typescript/lib/tsc.js:88057
                throw e;
                ^

RangeError: Maximum call stack size exceeded
    at forEachSymbolTableInScope (/Users/bluepichu/.config/yarn/global/node_modules/typescript/lib/tsc.js:38598:31)
    at getAccessibleSymbolChain (/Users/bluepichu/.config/yarn/global/node_modules/typescript/lib/tsc.js:38617:20)
    at isAnySymbolAccessible (/Users/bluepichu/.config/yarn/global/node_modules/typescript/lib/tsc.js:38727:45)
    at isSymbolAccessibleWorker (/Users/bluepichu/.config/yarn/global/node_modules/typescript/lib/tsc.js:38770:30)
    at isTypeSymbolAccessible (/Users/bluepichu/.config/yarn/global/node_modules/typescript/lib/tsc.js:38709:26)
    at typeToTypeNodeHelper (/Users/bluepichu/.config/yarn/global/node_modules/typescript/lib/tsc.js:39169:26)
    at typeToTypeNodeHelper (/Users/bluepichu/.config/yarn/global/node_modules/typescript/lib/tsc.js:39226:41)
    at mapToTypeNodes (/Users/bluepichu/.config/yarn/global/node_modules/typescript/lib/tsc.js:39676:40)
    at typeToTypeNodeHelper (/Users/bluepichu/.config/yarn/global/node_modules/typescript/lib/tsc.js:39186:37)
    at typeToTypeNodeOrCircularityElision (/Users/bluepichu/.config/yarn/global/node_modules/typescript/lib/tsc.js:39252:28)

🙂 Expected behavior

src/b.ts:5:49 - error TS2345: Argument of type 'Obj' is not assignable to parameter of type 'TupleIntersection<Types>'.

5   <Obj>(obj: Obj) => intersectionCheck<Types>()(obj);
                                                  ~~~


Found 1 error.

Notes and Workaround

If TupleIntersection is exported by a.ts, then you get the compile error as expected and no crash, even if b.ts doesn't explicitly import it. This is because, since a.ts is exporting TupleIntersection, it can be referenced in b.d.ts as import("./a").TupleIntersection.

I think the issue here is that declaration emit is trying to infinitely unroll the conditional type since it has no name for the type that it can reference. I'm not really sure what the compiler is supposed to do in this case though. (Maybe it should complain at the intersectionCheck declaration in a.ts that it's using a private name that needs to be exported?)

I think this is probably the same issue referenced by this comment on #42948, though the top-level issue there seems to have a different (though possibly related) cause.

[weswigham]

This no longer crashes and reports the error as expected. The declaration emit output is

export declare const intersectionCheckWrapper: <Types extends unknown[] = []>() => <Obj>(obj: Obj) => Types extends [] ? unknown : Types extends [infer Hd, ...infer Tl] ? Hd & (Tl extends [] ? unknown : Tl extends [infer Hd, ...infer Tl] ? Hd & (Tl extends [] ? unknown : Tl extends [infer Hd, ...infer Tl] ? Hd & (Tl extends [] ? unknown : Tl extends [infer Hd, ...infer Tl] ? Hd & (Tl extends [] ? unknown : Tl extends [infer Hd, ...infer Tl] ? Hd & (Tl extends [] ? unknown : Tl extends [infer Hd, ...infer Tl] ? Hd & (Tl extends [] ? unknown : Tl extends [infer Hd, ...infer Tl] ? Hd & (Tl extends [] ? unknown : Tl extends [infer Hd, ...infer Tl] ? Hd & (Tl extends [] ? unknown : Tl extends [infer Hd, ...infer Tl] ? Hd & (Tl extends [] ? unknown : Tl extends [infer Hd, ...infer Tl] ? Hd & (Tl extends [] ? unknown : Tl extends [infer Hd, ...infer Tl] ? Hd & any : never) : never) : never) : never) : never) : never) : never) : never) : never) : never) : never;

which isn't full fidelity (since that'd need inline type aliases), but 10 expansions is pretty OK.