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|
=== tests/cases/compiler/narrowingUnionToUnion.ts ===
type Falsy = false | 0 | 0n | '' | null | undefined;
>Falsy : false | "" | 0 | 0n | null | undefined
>false : false
>null : null
declare function isFalsy(value: unknown): value is Falsy;
>isFalsy : (value: unknown) => value is Falsy
>value : unknown
function fx1(x: string | number | undefined) {
>fx1 : (x: string | number | undefined) => void
>x : string | number | undefined
if (isFalsy(x)) {
>isFalsy(x) : boolean
>isFalsy : (value: unknown) => value is Falsy
>x : string | number | undefined
x; // "" | 0 | undefined
>x : "" | 0 | undefined
}
}
function fx2<T>(x: T | undefined) {
>fx2 : <T>(x: T | undefined) => void
>x : T | undefined
if (isFalsy(x)) {
>isFalsy(x) : boolean
>isFalsy : (value: unknown) => value is Falsy
>x : T | undefined
x; // T & Falsy | undefined
>x : (T & null) | (T & false) | (T & "") | (T & 0) | (T & 0n) | undefined
}
}
function fx3<T extends string | number>(x: T) {
>fx3 : <T extends string | number>(x: T) => void
>x : T
if (isFalsy(x)) {
>isFalsy(x) : boolean
>isFalsy : (value: unknown) => value is Falsy
>x : string | number
x; // T & "" | T & 0
>x : (T & "") | (T & 0)
}
}
declare function isA(obj: unknown): obj is { a: false } | { b: 0 };
>isA : (obj: unknown) => obj is { a: false; } | { b: 0; }
>obj : unknown
>a : false
>false : false
>b : 0
function fx4(obj: { b: number }) {
>fx4 : (obj: { b: number;}) => void
>obj : { b: number; }
>b : number
if (isA(obj)) {
>isA(obj) : boolean
>isA : (obj: unknown) => obj is { a: false; } | { b: 0; }
>obj : { b: number; }
obj; // { b: 0 }
>obj : { b: 0; }
}
}
declare class X { x: string }
>X : X
>x : string
declare class XS extends X { xs: string }
>XS : XS
>X : X
>xs : string
declare class Y { y: string }
>Y : Y
>y : string
declare class YS extends Y { ys: string }
>YS : YS
>Y : Y
>ys : string
declare function isXSorY(obj: unknown): obj is XS | Y;
>isXSorY : (obj: unknown) => obj is XS | Y
>obj : unknown
function fx5<T extends X>(obj: X | YS, c: typeof XS | typeof Y) {
>fx5 : <T extends X>(obj: X | YS, c: typeof XS | typeof Y) => void
>obj : X | YS
>c : typeof XS | typeof Y
>XS : typeof XS
>Y : typeof Y
if (obj instanceof c) {
>obj instanceof c : boolean
>obj : X | YS
>c : typeof XS | typeof Y
obj; // XS | YS
>obj : XS | YS
}
if (isXSorY(obj)) {
>isXSorY(obj) : boolean
>isXSorY : (obj: unknown) => obj is XS | Y
>obj : X | YS
obj; // XS | YS
>obj : XS | YS
}
}
// Repro from #31156
declare function isEmptyStrOrUndefined(mixed: any): mixed is "" | undefined;
>isEmptyStrOrUndefined : (mixed: any) => mixed is "" | undefined
>mixed : any
function fx10(s: string | undefined) {
>fx10 : (s: string | undefined) => void
>s : string | undefined
if (isEmptyStrOrUndefined(s)) {
>isEmptyStrOrUndefined(s) : boolean
>isEmptyStrOrUndefined : (mixed: any) => mixed is "" | undefined
>s : string | undefined
s; // "" | undefined
>s : "" | undefined
if (s == undefined) {
>s == undefined : boolean
>s : "" | undefined
>undefined : undefined
s; // undefined
>s : undefined
}
else {
s; // ""
>s : ""
}
}
}
// Repro from #37807
function f1(x: any): asserts x is number | undefined { }
>f1 : (x: any) => asserts x is number | undefined
>x : any
let v1: number | string | undefined;
>v1 : string | number | undefined
f1(v1);
>f1(v1) : void
>f1 : (x: any) => asserts x is number | undefined
>v1 : string | number | undefined
v1; // number | undefined
>v1 : number | undefined
function f2(x: any): asserts x is 6 | undefined { }
>f2 : (x: any) => asserts x is 6 | undefined
>x : any
let v2: number | string | undefined;
>v2 : string | number | undefined
f2(v2);
>f2(v2) : void
>f2 : (x: any) => asserts x is 6 | undefined
>v2 : string | number | undefined
v2; // 6 | undefined
>v2 : 6 | undefined
// #39105
declare function isEmptyString(value: string): value is '';
>isEmptyString : (value: string) => value is ""
>value : string
declare function isMaybeEmptyString(value: string | null | undefined): value is '' | null | undefined;
>isMaybeEmptyString : (value: string | null | undefined) => value is "" | null | undefined
>value : string | null | undefined
>null : null
>null : null
declare function isZero(value: number): value is 0;
>isZero : (value: number) => value is 0
>value : number
declare function isMaybeZero(value: number | null | undefined): value is 0 | null | undefined;
>isMaybeZero : (value: number | null | undefined) => value is 0 | null | undefined
>value : number | null | undefined
>null : null
>null : null
declare function isEmptyArray<T>(value: T[]): value is [];
>isEmptyArray : <T>(value: T[]) => value is []
>value : T[]
declare function isMaybeEmptyArray<T>(value: T[] | null | undefined): value is [] | null | undefined;
>isMaybeEmptyArray : <T>(value: T[] | null | undefined) => value is [] | null | undefined
>value : T[] | null | undefined
>null : null
>null : null
const TEST_CASES = [
>TEST_CASES : (((value: string) => void) | ((value: number) => void) | ((value: string[]) => void))[]
>[ (value: string) => { if (isEmptyString(value)) { value; // "" } else { value; // string } if (isMaybeEmptyString(value)) { value; // "" } else { value; // string } }, (value?: string) => { if (isMaybeEmptyString(value)) { value; // "" | undefined } else { value; // string } }, (value: number) => { if (isZero(value)) { value; // 0 } else { value; // number } if (isMaybeZero(value)) { value; // 0 } else { value; // number } }, (value?: number) => { if (isMaybeZero(value)) { value; // 0 | undefined } else { value; // number } }, (value: string[]) => { if (isEmptyArray(value)) { value; // [] } else { value; // string[] } if (isMaybeEmptyArray(value)) { value; // [] } else { value; // string[] } }, (value?: string[]) => { if (isMaybeEmptyArray(value)) { value; // [] | undefined } else { value; // string[] } },] : (((value: string) => void) | ((value: number) => void) | ((value: string[]) => void))[]
(value: string) => {
>(value: string) => { if (isEmptyString(value)) { value; // "" } else { value; // string } if (isMaybeEmptyString(value)) { value; // "" } else { value; // string } } : (value: string) => void
>value : string
if (isEmptyString(value)) {
>isEmptyString(value) : boolean
>isEmptyString : (value: string) => value is ""
>value : string
value; // ""
>value : ""
}
else {
value; // string
>value : string
}
if (isMaybeEmptyString(value)) {
>isMaybeEmptyString(value) : boolean
>isMaybeEmptyString : (value: string | null | undefined) => value is "" | null | undefined
>value : string
value; // ""
>value : ""
}
else {
value; // string
>value : string
}
},
(value?: string) => {
>(value?: string) => { if (isMaybeEmptyString(value)) { value; // "" | undefined } else { value; // string } } : (value?: string) => void
>value : string | undefined
if (isMaybeEmptyString(value)) {
>isMaybeEmptyString(value) : boolean
>isMaybeEmptyString : (value: string | null | undefined) => value is "" | null | undefined
>value : string | undefined
value; // "" | undefined
>value : "" | undefined
}
else {
value; // string
>value : string
}
},
(value: number) => {
>(value: number) => { if (isZero(value)) { value; // 0 } else { value; // number } if (isMaybeZero(value)) { value; // 0 } else { value; // number } } : (value: number) => void
>value : number
if (isZero(value)) {
>isZero(value) : boolean
>isZero : (value: number) => value is 0
>value : number
value; // 0
>value : 0
}
else {
value; // number
>value : number
}
if (isMaybeZero(value)) {
>isMaybeZero(value) : boolean
>isMaybeZero : (value: number | null | undefined) => value is 0 | null | undefined
>value : number
value; // 0
>value : 0
}
else {
value; // number
>value : number
}
},
(value?: number) => {
>(value?: number) => { if (isMaybeZero(value)) { value; // 0 | undefined } else { value; // number } } : (value?: number) => void
>value : number | undefined
if (isMaybeZero(value)) {
>isMaybeZero(value) : boolean
>isMaybeZero : (value: number | null | undefined) => value is 0 | null | undefined
>value : number | undefined
value; // 0 | undefined
>value : 0 | undefined
}
else {
value; // number
>value : number
}
},
(value: string[]) => {
>(value: string[]) => { if (isEmptyArray(value)) { value; // [] } else { value; // string[] } if (isMaybeEmptyArray(value)) { value; // [] } else { value; // string[] } } : (value: string[]) => void
>value : string[]
if (isEmptyArray(value)) {
>isEmptyArray(value) : boolean
>isEmptyArray : <T>(value: T[]) => value is []
>value : string[]
value; // []
>value : []
}
else {
value; // string[]
>value : string[]
}
if (isMaybeEmptyArray(value)) {
>isMaybeEmptyArray(value) : boolean
>isMaybeEmptyArray : <T>(value: T[] | null | undefined) => value is [] | null | undefined
>value : string[]
value; // []
>value : []
}
else {
value; // string[]
>value : string[]
}
},
(value?: string[]) => {
>(value?: string[]) => { if (isMaybeEmptyArray(value)) { value; // [] | undefined } else { value; // string[] } } : (value?: string[]) => void
>value : string[] | undefined
if (isMaybeEmptyArray(value)) {
>isMaybeEmptyArray(value) : boolean
>isMaybeEmptyArray : <T>(value: T[] | null | undefined) => value is [] | null | undefined
>value : string[] | undefined
value; // [] | undefined
>value : [] | undefined
}
else {
value; // string[]
>value : string[]
}
},
];
// Repro from #42101
type EmptyString = '' | null | undefined;
>EmptyString : "" | null | undefined
>null : null
function isEmpty(value: string | EmptyString): value is EmptyString {
>isEmpty : (value: string | EmptyString) => value is EmptyString
>value : string | null | undefined
return value === '' || value === null || value === undefined;
>value === '' || value === null || value === undefined : boolean
>value === '' || value === null : boolean
>value === '' : boolean
>value : string | null | undefined
>'' : ""
>value === null : boolean
>value : string | null | undefined
>null : null
>value === undefined : boolean
>value : string | undefined
>undefined : undefined
}
let test: string | null | undefined;
>test : string | null | undefined
>null : null
if (isEmpty(test)) {
>isEmpty(test) : boolean
>isEmpty : (value: string | null | undefined) => value is EmptyString
>test : string | null | undefined
test; // EmptyString
>test : EmptyString
}
// Repro from #43825
declare function assert<T>(value: any): asserts value is T
>assert : <T>(value: any) => asserts value is T
>value : any
function test1(foo: number | string | boolean) {
>test1 : (foo: number | string | boolean) => void
>foo : string | number | boolean
assert<1 | string>(foo);
>assert<1 | string>(foo) : void
>assert : <T>(value: any) => asserts value is T
>foo : string | number | boolean
foo; // string | 1
>foo : string | 1
}
// Repro from #46909
function check1(x: unknown): x is (string | 0) {
>check1 : (x: unknown) => x is string | 0
>x : unknown
return typeof x === "string" || x === 0;
>typeof x === "string" || x === 0 : boolean
>typeof x === "string" : boolean
>typeof x : "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"
>x : unknown
>"string" : "string"
>x === 0 : boolean
>x : unknown
>0 : 0
}
function check2(x: unknown): x is ("hello" | 0) {
>check2 : (x: unknown) => x is 0 | "hello"
>x : unknown
return x === "hello" || x === 0;
>x === "hello" || x === 0 : boolean
>x === "hello" : boolean
>x : unknown
>"hello" : "hello"
>x === 0 : boolean
>x : unknown
>0 : 0
}
function test3(x: unknown) {
>test3 : (x: unknown) => void
>x : unknown
if (typeof x === "string" || x === 0) {
>typeof x === "string" || x === 0 : boolean
>typeof x === "string" : boolean
>typeof x : "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"
>x : unknown
>"string" : "string"
>x === 0 : boolean
>x : unknown
>0 : 0
x; // string | 0
>x : string | 0
if (x === "hello" || x === 0) {
>x === "hello" || x === 0 : boolean
>x === "hello" : boolean
>x : string | 0
>"hello" : "hello"
>x === 0 : boolean
>x : string | 0
>0 : 0
x; // 0 | "hello"
>x : 0 | "hello"
}
}
if (check1(x)) {
>check1(x) : boolean
>check1 : (x: unknown) => x is string | 0
>x : unknown
x; // string | 0
>x : string | 0
if (check2(x)) {
>check2(x) : boolean
>check2 : (x: unknown) => x is 0 | "hello"
>x : string | 0
x; // 0 | "hello"
>x : 0 | "hello"
}
}
}
// Repro from #49588
function assertRelationIsNullOrStringArray(v: (string | number)[] | null): asserts v is string[] | null {}
>assertRelationIsNullOrStringArray : (v: (string | number)[] | null) => asserts v is string[] | null
>v : (string | number)[] | null
>null : null
>null : null
function f1x(obj: (string | number)[] | null) {
>f1x : (obj: (string | number)[] | null) => void
>obj : (string | number)[] | null
>null : null
assertRelationIsNullOrStringArray(obj);
>assertRelationIsNullOrStringArray(obj) : void
>assertRelationIsNullOrStringArray : (v: (string | number)[] | null) => asserts v is string[] | null
>obj : (string | number)[] | null
obj; // string[] | null
>obj : string[] | null
}
|
