Crash: TypeError: Cannot read properties of undefined (reading 'flags') in isFreshLiteralType during recursive tuple expansion with unresolved identifiers

[na7ure-a]

🔎 Search Terms

isFreshLiteralType

Cannot read properties of undefined (reading 'flags')

getNormalizedType

"Internal Compiler Error"

"Large tuple crash"

🕗 Version & Regression Information

v5.7.3: Crashes

v5.8.3: Crashes

v5.9.3: Crashes

Nightly (6.0.0-dev.20260108): Crashes

⏯ Playground Link

https://www.typescriptlang.org/zh/play/?target=7&ts=6.0.0-dev.20260111#code/PTAECUFMAcCcHtQDMEFtQGICsAWHBOARgCgAXAT2klAFUA7AZwAsBLJUgFQFdoAbSADwdQkAB6lIdACYNQAbQB0SgIZ1ycgLoaAfKAC8oYWInTZcjnIAMGgDRKFLOkkixDylrw2gA-G4+gALlA6SAA3FwBuMkpqAFFRaFUpAGVUZV5+WG4+SAYhEXFJGXl7VXUtXQMjQtN5C2s7JUdnVw53Tx9DUAAfUHjE6VT0zOz+PLaPXSDNKIoqUGTWdgEAQQKTYpXYWGVyATLtStAACmPS2ABzBiCVgEp9XVD4Fil74yLZM5VL6-kVq1soHszRcEA09z0j2eUk64ECwTCkWi8wA4ggAO79KChVbrD6gLY7PYHGygAByeNqdC4qAARi5SQAFSmbba7VZs4lqQ5Hf4Acn4dAupCYfK871qFN8ayCaPgmIS2IEiiUK0aCkZAI0cjJ4pqxS40kgSEckBhvhVCjV9k11i8N1JZNJizYpAEjMOURAoDm1DlCuguIlrKJ+25jpZsmpdIZoGZwdkhPZSa55B5+hKqtJ9hW2t1kdAhqkxtN5tA-v6ypz2dVgKdfxrGp08IrirCq0dTO0sxi5YxlbWCYJnLDaYjQ+j9NgTILKY5oYOhwzluttZ1eo2siLJZCZdbgZXNgAxjtmHXSXI1UClIzm7L+22cVf6x6e-NRoIOOP9VGaVOjpOoJDlKw6hhwUzkgWlidJo8IUkOhAwRw9p9vKlbmOe8iaDoUTFkevDKLA1D4coDCJpyABq6QvMopDwLA+RDoaADWdDynQmikgAkhmFiAbAzYAN7EKAomgIKwpMOAqgXIIyQFvxpKxApf4uNoxwMKQhGkEEySkkUABCxr0ZAQSxLcNyUdRUi0fRAjxPhXDFvZCRJEMGQuB+eT0MwroflWSj+VxSnaDo2hKa5gxpB5WQ8GMAg+UsnBxYIlpBc6oU8t2xAAL5AA

💻 Code

// Repro from #54491
type UnshiftTuple<T extends [...any[]]> = T extends [T[0],...infer Tail] ? Tail : never;
type ExpandSmallerTuples<T extends [...any[]]> = T extends [T[0],...infer Tail] ? T | ExpandSmallerTuples<Tail> : [];
type Shift<A extends Array<any>> = ((...args: A) => void) extends (...args: [A[0], ...infer R]) => void ? R : never;
type GrowExpRev<A extends Array<any>, N extends number, P extends Array<Array<any>>> = A['length'] extends N ? A : GrowExpRev<[...A,...P[0]][N] extends undefined ? [...A,...P[0]] : A, N, Shift<P>>;
// type GrowExp<A extends Array<any>, N extends number, P extends Array<Array<any>>> = [...A, ...A][N] extends undefined ? GrowExp<[...A, ...A], N, [A, ...P]> : GrowExpRev<A, N, P>;
type GrowExp<A extends Array<any>, N extends number, P extends Array<Array<any>>> = [...A,...A][N] extends undefined ? GrowExp<[...A,crash], N, [A, ...P]> : GrowExpRev<A, N, P>;
type Tuple<T, N extends number> = number extends N ? Array<T> : N extends 0 ? [] : N extends 1 ? [T] : GrowExp<[T], N, [[]]>;
declare class ArrayValidator<T extends unknown[], I = T[number]> {
    lengthRange<S extends number, E extends number>(start: S, endBefore: E): ArrayValidator<Exclude<ExpandSmallerTuples<UnshiftTuple<[...Tuple<I, E>]>>, ExpandSmallerTuples<UnshiftTuple<[...Tuple<I, S>]>>>>;
}

🙁 Actual behavior

.\ts-versions\nightly\node_modules\.bin\tsc.cmd  .\mutated\largeTupleTypes_mutated_batch0.ts
D:\do\typeFuzz\ts-versions\nightly\node_modules\typescript\lib\_tsc.js:123166
      throw e;
      ^

TypeError: Cannot read properties of undefined (reading 'flags')
    at isFreshLiteralType (D:\do\typeFuzz\ts-versions\nightly\node_modules\typescript\lib\_tsc.js:62933:20)                                                                                              
    at getNormalizedType (D:\do\typeFuzz\ts-versions\nightly\node_modules\typescript\lib\_tsc.js:64661:17)                                                                                               
    at isRelatedTo (D:\do\typeFuzz\ts-versions\nightly\node_modules\typescript\lib\_tsc.js:65015:21)                                                                                                     
    at propertiesRelatedTo (D:\do\typeFuzz\ts-versions\nightly\node_modules\typescript\lib\_tsc.js:66695:29)                                                                                             
    at structuredTypeRelatedToWorker (D:\do\typeFuzz\ts-versions\nightly\node_modules\typescript\lib\_tsc.js:66300:21)                                                                                   
    at structuredTypeRelatedTo (D:\do\typeFuzz\ts-versions\nightly\node_modules\typescript\lib\_tsc.js:65726:21)                                                                                         
    at recursiveTypeRelatedTo (D:\do\typeFuzz\ts-versions\nightly\node_modules\typescript\lib\_tsc.js:65677:19)                                                                                          
    at isRelatedTo (D:\do\typeFuzz\ts-versions\nightly\node_modules\typescript\lib\_tsc.js:65090:122)                                                                                                    
    at typeArgumentsRelatedTo (D:\do\typeFuzz\ts-versions\nightly\node_modules\typescript\lib\_tsc.js:65508:25)                                                                                          
    at relateVariances (D:\do\typeFuzz\ts-versions\nightly\node_modules\typescript\lib\_tsc.js:66341:23)                                                                                                 

Node.js v22.19.0

🙂 Expected behavior

The compiler should not crash.

Additional information about the issue

No response

[Andarist]

Repros with (and this doesn't depend anyhow on unresolved identifiers/error types/etc):

type Inner<A extends any[], A2 extends [...A, boolean]> = A2;

export type Wrapper<A extends any[]> = Inner<
  A,
  [...A, boolean, boolean, boolean, boolean]
>;

[RyanCavanaugh]

Repros in TS7 as well