Unary minus on 'any' should infer type to 'number | bigint', not just 'number'

🔎 Search Terms

"unary minus", "negate bigint"

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about bigint

⏯ Playground Link

https://www.typescriptlang.org/play/?target=99&ts=5.7.2#code/MYewdgzgLgBARjAvDAtACgIxgJQG4BQA9ITKTAHoD8+okscATEqnAcWRdTeNDGM+gx4iJMlW50+TZCjBtRpcRN4BDAFwwVYAJ7NWIjuNq8AHgJXzDXY7FoA3Zmjsat27EgB8qO5bHUbMABOzPZocMLsfsq24HbSME4aYACuALZwAKbBAD7wAJYA5nlgUO6IXig+BlEBgfH2DGERCpz4QA

💻 Code

const b = -(1n);
//    ^?
const b2 = -b;
//    ^?

const n = -(1);
//    ^?
const n2 = -n;
//    ^?

const a: any = b;
//    ^?
const x = -a;
//    ^?

const conv = (v: any) => -v;
//    ^?
const r = conv(b);
//    ^?
const conv2 = (v: number | bigint) => -v;
//    ^?
const r2 = conv2(b);
//    ^?

🙁 Actual behavior

Applying an unary minus on an any variable infers the type to number (as can be seen in the "hat-question mark" comments or the .D.TS tab for x, conv, and r). The inferred type for the constants x and r is thus wrong (they actually contain a BigInt value).

Unary minus on a number correctly infers number, and (more importantly) unary minus on a bigint correctly infers bigint. Same for unary minus on a number | bigint which infers number | bigint.

🙂 Expected behavior

Applying an unary minus on an any variable should infer the type to number | bigint.

ECMAScript specifies (https://tc39.es/ecma262/multipage/ecmascript-language-expressions.html#sec-unary-minus-operator) unary minus as doing a ToNumeric (which returns either a Number of a BigInt) and then applying the appropriate unaryMinus abstract operation depending on the type of the value. The result is thus either a Number or a BigInt.

(the unary plus operator however converts to Number values only)

Additional information about the issue

No response

Beginne mit dem verlinkten TypeScript Playground und reproduziere die abgeleiteten Typen für unäres Minus bei any, number, bigint und number | bigint. Verfolge die Behandlung der Typinferenz für unäres Minus durch den Compiler und die zugehörigen Tests; abgeschlossen ist die Aufgabe, wenn unäres Minus mit any als number | bigint abgeleitet wird, während das bestehende Verhalten für number und bigint korrekt bleibt.