1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313
|
=== tests/cases/compiler/conditionalTypeAssignabilityWhenDeferred.ts ===
export type FilterPropsByType<T, TT> = {
>FilterPropsByType : FilterPropsByType<T, TT>
[K in keyof T]: T[K] extends TT ? K : never
}[keyof T];
function select<
>select : <T extends string | number, TList extends object, TValueProp extends FilterPropsByType<TList, T>>(property: T, list: TList[], valueProp: TValueProp) => void
T extends string | number,
TList extends object,
TValueProp extends FilterPropsByType<TList, T>
>(property: T, list: TList[], valueProp: TValueProp) {}
>property : T
>list : TList[]
>valueProp : TValueProp
export function func<XX extends string>(x: XX, tipos: { value: XX }[]) {
>func : <XX extends string>(x: XX, tipos: { value: XX;}[]) => void
>x : XX
>tipos : { value: XX; }[]
>value : XX
select(x, tipos, "value");
>select(x, tipos, "value") : void
>select : <T extends string | number, TList extends object, TValueProp extends FilterPropsByType<TList, T>>(property: T, list: TList[], valueProp: TValueProp) => void
>x : XX
>tipos : { value: XX; }[]
>"value" : "value"
}
declare function onlyNullablePlease<T extends null extends T ? any : never>(
>onlyNullablePlease : <T extends null extends T ? any : never>(value: T) => void
>null : null
value: T
>value : T
): void;
declare function onlyNullablePlease2<
>onlyNullablePlease2 : <T extends [null] extends [T] ? any : never>(value: T) => void
T extends [null] extends [T] ? any : never
>null : null
>(value: T): void;
>value : T
declare var z: string | null;
>z : string | null
>null : null
onlyNullablePlease(z); // works as expected
>onlyNullablePlease(z) : void
>onlyNullablePlease : <T extends null extends T ? any : never>(value: T) => void
>z : string | null
onlyNullablePlease2(z); // works as expected
>onlyNullablePlease2(z) : void
>onlyNullablePlease2 : <T extends [null] extends [T] ? any : never>(value: T) => void
>z : string | null
declare var y: string;
>y : string
onlyNullablePlease(y); // error as expected
>onlyNullablePlease(y) : void
>onlyNullablePlease : <T extends null extends T ? any : never>(value: T) => void
>y : string
onlyNullablePlease2(y); // error as expected
>onlyNullablePlease2(y) : void
>onlyNullablePlease2 : <T extends [null] extends [T] ? any : never>(value: T) => void
>y : string
function f<T>(t: T) {
>f : <T>(t: T) => void
>t : T
var x: T | null = Math.random() > 0.5 ? null : t;
>x : T | null
>null : null
>Math.random() > 0.5 ? null : t : T | null
>Math.random() > 0.5 : boolean
>Math.random() : number
>Math.random : () => number
>Math : Math
>random : () => number
>0.5 : 0.5
>null : null
>t : T
onlyNullablePlease(x); // should work
>onlyNullablePlease(x) : void
>onlyNullablePlease : <T extends null extends T ? any : never>(value: T) => void
>x : T | null
onlyNullablePlease2(x); // should work
>onlyNullablePlease2(x) : void
>onlyNullablePlease2 : <T extends [null] extends [T] ? any : never>(value: T) => void
>x : T | null
}
function f2<T>(t1: { x: T; y: T }, t2: T extends T ? { x: T; y: T } : never) {
>f2 : <T>(t1: { x: T; y: T;}, t2: T extends T ? { x: T; y: T;} : never) => void
>t1 : { x: T; y: T; }
>x : T
>y : T
>t2 : T extends T ? { x: T; y: T; } : never
>x : T
>y : T
t1 = t2; // OK
>t1 = t2 : T extends T ? { x: T; y: T; } : never
>t1 : { x: T; y: T; }
>t2 : T extends T ? { x: T; y: T; } : never
t2 = t1; // should fail
>t2 = t1 : { x: T; y: T; }
>t2 : T extends T ? { x: T; y: T; } : never
>t1 : { x: T; y: T; }
}
type Foo<T> = T extends true ? string : "a";
>Foo : Foo<T>
>true : true
function test<T>(x: Foo<T>, s: string) {
>test : <T>(x: Foo<T>, s: string) => void
>x : Foo<T>
>s : string
x = "a"; // Currently an error, should be ok
>x = "a" : "a"
>x : Foo<T>
>"a" : "a"
x = s; // Error
>x = s : string
>x : Foo<T>
>s : string
}
// #26933
type Distributive<T> = T extends { a: number } ? { a: number } : { b: number };
>Distributive : Distributive<T>
>a : number
>a : number
>b : number
function testAssignabilityToConditionalType<T>() {
>testAssignabilityToConditionalType : <T>() => void
const o = { a: 1, b: 2 };
>o : { a: number; b: number; }
>{ a: 1, b: 2 } : { a: number; b: number; }
>a : number
>1 : 1
>b : number
>2 : 2
const x: [T] extends [string]
>x : [T] extends [string] ? { y: number; } : { a: number; b: number; }
? { y: number }
>y : number
: { a: number; b: number } = undefined!;
>a : number
>b : number
>undefined! : never
>undefined : undefined
// Simple case: OK
const o1: [T] extends [number] ? { a: number } : { b: number } = o;
>o1 : [T] extends [number] ? { a: number; } : { b: number; }
>a : number
>b : number
>o : { a: number; b: number; }
// Simple case where source happens to be a conditional type: also OK
const x1: [T] extends [number]
>x1 : [T] extends [number] ? [T] extends [string] ? { y: number; } : { a: number; } : [T] extends [string] ? { y: number; } : { b: number; }
? ([T] extends [string] ? { y: number } : { a: number })
>y : number
>a : number
: ([T] extends [string] ? { y: number } : { b: number }) = x;
>y : number
>b : number
>x : [T] extends [string] ? { y: number; } : { a: number; b: number; }
// Infer type parameters: no good
const o2: [T] extends [[infer U]] ? U : { b: number } = o;
>o2 : [T] extends [[infer U]] ? U : { b: number; }
>b : number
>o : { a: number; b: number; }
// The next 4 are arguable - if you choose to ignore the `never` distribution case,
// then they're all good. The `never` case _is_ a bit of an outlier - we say distributive types
// look approximately like the sum of their branches, but the `never` case bucks that.
// There's an argument for the result of dumping `never` into a distributive conditional
// being not `never`, but instead the intersection of the branches - a much more precise bound
// on that "impossible" input.
// Distributive where T might instantiate to never: no good
const o3: Distributive<T> = o;
>o3 : Distributive<T>
>o : { a: number; b: number; }
// Distributive where T & string might instantiate to never: also no good
const o4: Distributive<T & string> = o;
>o4 : Distributive<T & string>
>o : { a: number; b: number; }
// Distributive where {a: T} cannot instantiate to never: OK
const o5: Distributive<{ a: T }> = o;
>o5 : Distributive<{ a: T; }>
>a : T
>o : { a: number; b: number; }
// Distributive where check type is a conditional which returns a non-never type upon instantiation with `never` but can still return never otherwise: no good
const o6: Distributive<[T] extends [never] ? { a: number } : never> = o;
>o6 : Distributive<[T] extends [never] ? { a: number; } : never>
>a : number
>o : { a: number; b: number; }
}
type Wrapped<T> = { ___secret: T };
>Wrapped : Wrapped<T>
>___secret : T
type Unwrap<T> = T extends Wrapped<infer U> ? U : T;
>Unwrap : Unwrap<T>
declare function set<T, K extends keyof T>(
>set : <T, K extends keyof T>(obj: T, key: K, value: Unwrap<T[K]>) => Unwrap<T[K]>
obj: T,
>obj : T
key: K,
>key : K
value: Unwrap<T[K]>
>value : Unwrap<T[K]>
): Unwrap<T[K]>;
class Foo2 {
>Foo2 : Foo2
prop!: Wrapped<string>;
>prop : Wrapped<string>
method() {
>method : () => void
set(this, "prop", "hi"); // <-- type error
>set(this, "prop", "hi") : Unwrap<this["prop"]>
>set : <T, K extends keyof T>(obj: T, key: K, value: Unwrap<T[K]>) => Unwrap<T[K]>
>this : this
>"prop" : "prop"
>"hi" : "hi"
}
}
set(new Foo2(), "prop", "hi"); // <-- typechecks
>set(new Foo2(), "prop", "hi") : string
>set : <T, K extends keyof T>(obj: T, key: K, value: Unwrap<T[K]>) => Unwrap<T[K]>
>new Foo2() : Foo2
>Foo2 : typeof Foo2
>"prop" : "prop"
>"hi" : "hi"
type InferBecauseWhyNot<T> = [T] extends [(p: infer P1) => any]
>InferBecauseWhyNot : InferBecauseWhyNot<T>
>p : P1
? P1 | T
: never;
function f3<Q extends (arg: any) => any>(x: Q): InferBecauseWhyNot<Q> {
>f3 : <Q extends (arg: any) => any>(x: Q) => InferBecauseWhyNot<Q>
>arg : any
>x : Q
return x;
>x : Q
}
type InferBecauseWhyNotDistributive<T> = T extends (p: infer P1) => any
>InferBecauseWhyNotDistributive : InferBecauseWhyNotDistributive<T>
>p : P1
? P1 | T
: never;
function f4<Q extends (arg: any) => any>(
>f4 : <Q extends (arg: any) => any>(x: Q) => InferBecauseWhyNotDistributive<Q>
>arg : any
x: Q
>x : Q
): InferBecauseWhyNotDistributive<Q> {
return x; // should fail
>x : Q
}
|