/
narrowingTypeofUndefined.types
58 lines (53 loc) · 2.11 KB
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narrowingTypeofUndefined.types
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=== tests/cases/compiler/narrowingTypeofUndefined.ts ===
declare const a: { error: { prop: string }, result: undefined } | { error: undefined, result: { prop: number } }
>a : { error: { prop: string;}; result: undefined; } | { error: undefined; result: { prop: number;}; }
>error : { prop: string; }
>prop : string
>result : undefined
>error : undefined
>result : { prop: number; }
>prop : number
if (typeof a.error === 'undefined') {
>typeof a.error === 'undefined' : boolean
>typeof a.error : "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"
>a.error : { prop: string; }
>a : { error: { prop: string; }; result: undefined; } | { error: undefined; result: { prop: number; }; }
>error : { prop: string; }
>'undefined' : "undefined"
a.result.prop; // number
>a.result.prop : number
>a.result : { prop: number; }
>a : { error: { prop: string; }; result: undefined; } | { error: undefined; result: { prop: number; }; }
>result : { prop: number; }
>prop : number
}
else {
a.error.prop; // string
>a.error.prop : string
>a.error : { prop: string; }
>a : { error: { prop: string; }; result: undefined; } | { error: undefined; result: { prop: number; }; }
>error : { prop: string; }
>prop : string
}
if (typeof a.error !== 'undefined') {
>typeof a.error !== 'undefined' : boolean
>typeof a.error : "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"
>a.error : { prop: string; }
>a : { error: { prop: string; }; result: undefined; } | { error: undefined; result: { prop: number; }; }
>error : { prop: string; }
>'undefined' : "undefined"
a.error.prop; // string
>a.error.prop : string
>a.error : { prop: string; }
>a : { error: { prop: string; }; result: undefined; } | { error: undefined; result: { prop: number; }; }
>error : { prop: string; }
>prop : string
}
else {
a.result.prop; // number
>a.result.prop : number
>a.result : { prop: number; }
>a : { error: { prop: string; }; result: undefined; } | { error: undefined; result: { prop: number; }; }
>result : { prop: number; }
>prop : number
}