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
|
class A { a: string; }
class B { b: string; }
function negativeClassesTest(x: A | B) {
if ("a" in x) {
x.b = "1";
} else {
x.a = "1";
}
}
function positiveClassesTest(x: A | B) {
if ("a" in x) {
x.b = "1";
} else {
x.a = "1";
}
}
class AWithOptionalProp { a?: string; }
class BWithOptionalProp { b?: string; }
function positiveTestClassesWithOptionalProperties(x: AWithOptionalProp | BWithOptionalProp) {
if ("a" in x) {
x.a = "1";
} else {
x.b = "1";
}
}
class AWithMethod {
a(): string { return ""; }
}
class BWithMethod {
b(): string { return ""; }
}
function negativeTestClassesWithMembers(x: AWithMethod | BWithMethod) {
if ("a" in x) {
x.a();
x.b();
} else {
}
}
function negativeTestClassesWithMemberMissingInBothClasses(x: AWithMethod | BWithMethod) {
if ("c" in x) {
x.a();
x.b();
} else {
x.a();
x.b();
}
}
class C { a: string; }
class D { a: string; }
function negativeMultipleClassesTest(x: A | B | C | D) {
if ("a" in x) {
x.b = "1";
} else {
x.a = "1";
}
}
class ClassWithUnionProp { prop: A | B }
function negativePropTest(x: ClassWithUnionProp) {
if ("a" in x.prop) {
let y: string = x.prop.b;
} else {
let z: string = x.prop.a;
}
}
class NegativeClassTest {
protected prop: A | B;
inThis() {
if ("a" in this.prop) {
let z: number = this.prop.b;
} else {
let y: string = this.prop.a;
}
}
}
class UnreachableCodeDetection {
a: string;
inThis() {
if ("a" in this) {
} else {
let y = this.a;
}
}
}
function positiveIntersectionTest(x: { a: string } & { b: string }) {
if ("a" in x) {
let s: string = x.a;
} else {
let n: never = x;
}
}
// Repro from #38608
declare const error: Error;
if ('extra' in error) {
error // Still Error
} else {
error // Error
}
function narrowsToNever(x: { l: number } | { r: number }) {
let v: number;
if ("l" in x) {
v = x.l;
}
else if ("r" in x) {
v = x.r;
}
else {
v = x
}
return v;
}
type AOrB = { aProp: number } | { bProp: number };
declare function isAOrB(x: unknown): x is AOrB;
declare var x: unknown;
if (isAOrB(x)) {
if ("aProp" in x) {
x.aProp;
}
else if ("bProp" in x) {
x.bProp;
}
// x is never because of the type predicate from unknown
else if ("cProp" in x) {
const _never: never = x;
}
}
function negativeIntersectionTest() {
if ("ontouchstart" in window) {
window.ontouchstart
} else {
window.ontouchstart
}
}
|
