swc/crates/swc_ecma_parser/tests/tsc/callChain.3.ts

12 lines
492 B
TypeScript

// @strict: true
declare function absorb<T>(): T;
declare const a: { m?<T>(obj: {x: T}): T } | undefined;
const n1: number = a?.m?.({x: 12 }); // should be an error (`undefined` is not assignable to `number`)
const n2: number = a?.m?.({x: absorb()}); // likewise
const n3: number | undefined = a?.m?.({x: 12}); // should be ok
const n4: number | undefined = a?.m?.({x: absorb()}); // likewise
// Also a test showing `!` vs `?` for good measure
let t1 = a?.m?.({x: 12});
t1 = a!.m!({x: 12});