1 // Copyright 2023 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "base/test/run_until.h"
6
7 #include <functional>
8
9 #include "base/callback_list.h"
10 #include "base/functional/callback.h"
11 #include "base/task/current_thread.h"
12 #include "base/test/scoped_run_loop_timeout.h"
13 #include "base/test/test_future.h"
14 #include "base/time/time_override.h"
15
16 namespace base::test {
17
TestPredicateOrRegisterOnNextIdleCallback(base::FunctionRef<bool (void)> condition,CallbackListSubscription * on_idle_callback_subscription,OnceClosure ready_callback)18 void TestPredicateOrRegisterOnNextIdleCallback(
19 base::FunctionRef<bool(void)> condition,
20 CallbackListSubscription* on_idle_callback_subscription,
21 OnceClosure ready_callback) {
22 if (condition()) {
23 // Invoke `ready_callback` if `condition` evaluates to true.
24 std::move(ready_callback).Run();
25 } else {
26 // Otherwise try again the next time the thread is idle.
27 *on_idle_callback_subscription =
28 CurrentThread::Get().RegisterOnNextIdleCallback(
29 {},
30 BindOnce(TestPredicateOrRegisterOnNextIdleCallback, condition,
31 on_idle_callback_subscription, std::move(ready_callback)));
32 }
33 }
34
RunUntil(base::FunctionRef<bool (void)> condition)35 bool RunUntil(base::FunctionRef<bool(void)> condition) {
36 // We expect a RunLoop timeout except under MOCK_TIME where TaskEnvironment
37 // disables TaskEnvironment::mock_time_domain_ after fast-forwarding into the
38 // timeout.
39 CHECK(test::ScopedRunLoopTimeout::ExistsForCurrentThread() ||
40 subtle::ScopedTimeClockOverrides::overrides_active())
41 << "No RunLoop timeout set, meaning `RunUntil` will hang forever on "
42 "failure.";
43
44 test::TestFuture<void> ready_signal;
45
46 CallbackListSubscription on_idle_callback_subscription;
47 on_idle_callback_subscription =
48 CurrentThread::Get().RegisterOnNextIdleCallback(
49 {},
50 BindOnce(TestPredicateOrRegisterOnNextIdleCallback, condition,
51 &on_idle_callback_subscription, ready_signal.GetCallback()));
52
53 return ready_signal.Wait();
54 }
55
56 } // namespace base::test
57