TypeScript/tests/cases/conformance/types/never/neverInference.ts
2017-11-12 21:05:28 -08:00

33 lines
816 B
TypeScript

// @lib: es2015
// @strict: true
// @target: es2015
declare function f1<T>(x: T[]): T;
let neverArray: never[] = [];
let a1 = f1([]); // never
let a2 = f1(neverArray); // never
// Repro from #19576
type Comparator<T> = (x: T, y: T) => number;
interface LinkedList<T> {
comparator: Comparator<T>,
nodes: Node<T>
}
type Node<T> = { value: T, next: Node<T> } | null
declare function compareNumbers(x: number, y: number): number;
declare function mkList<T>(items: T[], comparator: Comparator<T>): LinkedList<T>;
const list: LinkedList<number> = mkList([], compareNumbers);
// Repro from #19858
declare function f2<a>(as1: a[], as2: a[], cmp: (a1: a, a2: a) => number): void;
f2(Array.from([0]), [], (a1, a2) => a1 - a2);
f2(Array.from([]), [0], (a1, a2) => a1 - a2);