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1/*
2* Copyright (c) Microsoft Corporation. All rights reserved.
3* Copyright (c) 2023 Huawei Device Co., Ltd.
4* Licensed under the Apache License, Version 2.0 (the "License");
5* you may not use this file except in compliance with the License.
6* You may obtain a copy of the License at
7*
8*     http://www.apache.org/licenses/LICENSE-2.0
9*
10* Unless required by applicable law or agreed to in writing, software
11* distributed under the License is distributed on an "AS IS" BASIS,
12* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13* See the License for the specific language governing permissions and
14* limitations under the License.
15*
16* This file has been modified by Huawei to verify type inference by adding verification statements.
17*/
18
19// === tests/cases/conformance/types/intersection/intersectionOfUnionNarrowing.ts ===
20declare function AssertType(value:any, type:string):void;
21interface X {
22  a?: { aProp: string };
23  b?: { bProp: string };
24}
25type AorB = { a: object; b: undefined } | { a: undefined; b: object };
26
27declare const q: X & AorB;
28AssertType(q, "X & AorB");
29
30if (q.a !== undefined) {
31  q.a.aProp;
32AssertType(q.a.aProp, "string");
33AssertType(q.a, "{ aProp: string; } & object");
34
35} else {
36  // q.b is previously incorrectly inferred as potentially undefined
37  q.b.bProp;
38AssertType(q.b.bProp, "string");
39AssertType(q.b, "{ bProp: string; } & object");
40}
41
42
43