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
|
//// [conditionalTypesSimplifyWhenTrivial.ts]
const fn1 = <Params>(
params: Pick<Params, Exclude<keyof Params, never>>,
): Params => params;
function fn2<T>(x: Exclude<T, never>) {
var y: T = x;
x = y;
}
const fn3 = <Params>(
params: Pick<Params, Extract<keyof Params, keyof Params>>,
): Params => params;
function fn4<T>(x: Extract<T, T>) {
var y: T = x;
x = y;
}
declare var x: Extract<number | string, any>; // Should be `numebr | string` and not `any`
type ExtractWithDefault<T, U, D = never> = T extends U ? T : D;
type ExcludeWithDefault<T, U, D = never> = T extends U ? D : T;
const fn5 = <Params>(
params: Pick<Params, ExcludeWithDefault<keyof Params, never>>,
): Params => params;
function fn6<T>(x: ExcludeWithDefault<T, never>) {
var y: T = x;
x = y;
}
const fn7 = <Params>(
params: Pick<Params, ExtractWithDefault<keyof Params, keyof Params>>,
): Params => params;
function fn8<T>(x: ExtractWithDefault<T, T>) {
var y: T = x;
x = y;
}
type TemplatedConditional<TCheck, TExtends, TTrue, TFalse> = TCheck extends TExtends ? TTrue : TFalse;
const fn9 = <Params>(
params: Pick<Params, TemplatedConditional<keyof Params, never, never, keyof Params>>,
): Params => params;
function fn10<T>(x: TemplatedConditional<T, never, never, T>) {
var y: T = x;
x = y;
}
const fn11 = <Params>(
params: Pick<Params, TemplatedConditional<keyof Params, keyof Params, keyof Params, never>>,
): Params => params;
function fn12<T>(x: TemplatedConditional<T, T, T, never>) {
var y: T = x;
x = y;
}
declare var z: any;
const zee = z!!!; // since x is `any`, `x extends null | undefined` should be both true and false - and thus yield `any`
//// [conditionalTypesSimplifyWhenTrivial.js]
"use strict";
var fn1 = function (params) { return params; };
function fn2(x) {
var y = x;
x = y;
}
var fn3 = function (params) { return params; };
function fn4(x) {
var y = x;
x = y;
}
var fn5 = function (params) { return params; };
function fn6(x) {
var y = x;
x = y;
}
var fn7 = function (params) { return params; };
function fn8(x) {
var y = x;
x = y;
}
var fn9 = function (params) { return params; };
function fn10(x) {
var y = x;
x = y;
}
var fn11 = function (params) { return params; };
function fn12(x) {
var y = x;
x = y;
}
var zee = z; // since x is `any`, `x extends null | undefined` should be both true and false - and thus yield `any`
|
