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=== tests/cases/conformance/types/spread/spreadUnion3.ts ===
function f(x: { y: string } | undefined): { y: string } {
>f : Symbol(f, Decl(spreadUnion3.ts, 0, 0))
>x : Symbol(x, Decl(spreadUnion3.ts, 0, 11))
>y : Symbol(y, Decl(spreadUnion3.ts, 0, 15))
>y : Symbol(y, Decl(spreadUnion3.ts, 0, 43))
return { y: 123, ...x } // y: string | number
>y : Symbol(y, Decl(spreadUnion3.ts, 1, 12))
>x : Symbol(x, Decl(spreadUnion3.ts, 0, 11))
}
f(undefined)
>f : Symbol(f, Decl(spreadUnion3.ts, 0, 0))
>undefined : Symbol(undefined)
function g(t?: { a: number } | null): void {
>g : Symbol(g, Decl(spreadUnion3.ts, 3, 12))
>t : Symbol(t, Decl(spreadUnion3.ts, 6, 11))
>a : Symbol(a, Decl(spreadUnion3.ts, 6, 16))
let b = { ...t };
>b : Symbol(b, Decl(spreadUnion3.ts, 7, 7))
>t : Symbol(t, Decl(spreadUnion3.ts, 6, 11))
let c: number = b.a; // might not have 'a'
>c : Symbol(c, Decl(spreadUnion3.ts, 8, 7))
>b.a : Symbol(a, Decl(spreadUnion3.ts, 6, 16))
>b : Symbol(b, Decl(spreadUnion3.ts, 7, 7))
>a : Symbol(a, Decl(spreadUnion3.ts, 6, 16))
}
g()
>g : Symbol(g, Decl(spreadUnion3.ts, 3, 12))
g(undefined)
>g : Symbol(g, Decl(spreadUnion3.ts, 3, 12))
>undefined : Symbol(undefined)
g(null)
>g : Symbol(g, Decl(spreadUnion3.ts, 3, 12))
// spreading nothing but null and undefined is not allowed
declare const nullAndUndefinedUnion: null | undefined;
>nullAndUndefinedUnion : Symbol(nullAndUndefinedUnion, Decl(spreadUnion3.ts, 15, 13))
var x = { ...nullAndUndefinedUnion, ...nullAndUndefinedUnion };
>x : Symbol(x, Decl(spreadUnion3.ts, 16, 3))
>nullAndUndefinedUnion : Symbol(nullAndUndefinedUnion, Decl(spreadUnion3.ts, 15, 13))
>nullAndUndefinedUnion : Symbol(nullAndUndefinedUnion, Decl(spreadUnion3.ts, 15, 13))
var y = { ...nullAndUndefinedUnion };
>y : Symbol(y, Decl(spreadUnion3.ts, 17, 3))
>nullAndUndefinedUnion : Symbol(nullAndUndefinedUnion, Decl(spreadUnion3.ts, 15, 13))
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