1 //===-- FunctionTests.cpp -------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "support/Function.h"
10 #include "gmock/gmock.h"
11 #include "gtest/gtest.h"
12 
13 namespace clang {
14 namespace clangd {
15 namespace {
16 
17 TEST(EventTest, Subscriptions) {
18   Event<int> E;
19   int N = 0;
20   {
21     Event<int>::Subscription SubA;
22     // No subscriptions are active.
23     E.broadcast(42);
24     EXPECT_EQ(0, N);
25 
26     Event<int>::Subscription SubB = E.observe([&](int) { ++N; });
27     // Now one is active.
28     E.broadcast(42);
29     EXPECT_EQ(1, N);
30 
31     SubA = E.observe([&](int) { ++N; });
32     // Both are active.
33     EXPECT_EQ(1, N);
34     E.broadcast(42);
35     EXPECT_EQ(3, N);
36 
37     SubA = std::move(SubB);
38     // One is active.
39     EXPECT_EQ(3, N);
40     E.broadcast(42);
41     EXPECT_EQ(4, N);
42   }
43   // None are active.
44   EXPECT_EQ(4, N);
45   E.broadcast(42);
46   EXPECT_EQ(4, N);
47 }
48 
49 } // namespace
50 } // namespace clangd
51 } // namespace clang
52