Make test_scheduler more smart (#278)

src/tests/test_interval.cpp

@@ -20,45 +20,106 @@
 SCENARIO("interval emit values with provided interval", "[interval]")
 {
     auto scheduler = test_scheduler{};
-    auto mock = mock_observer<size_t>{};
+    auto mock      = mock_observer<size_t>{};
     GIVEN("interval observable")
     {
-        auto interval = std::chrono::seconds{ 1 };
-        auto obs = rpp::source::interval(interval, scheduler);
+        auto interval     = std::chrono::seconds{1};
+        auto obs          = rpp::source::interval(interval, scheduler);
+        auto initial_time = test_scheduler::worker_strategy::now();
+
         WHEN("subscribe on it via take 3")
         {
             obs.take(3).subscribe(mock);
-            THEN("observer obtains sequence of values")
+            THEN("nothing happens immediately till scheduler advanced")
             {
-                CHECK(mock.get_received_values() == std::vector<size_t>{0, 1, 2});
+                CHECK(mock.get_received_values() == std::vector<size_t>{});
                 CHECK(mock.get_on_error_count() == 0);
-                CHECK(mock.get_on_completed_count() == 1);
+                CHECK(mock.get_on_completed_count() == 0);
+                CHECK(scheduler.get_schedulings() == std::vector{ initial_time + interval});
+                CHECK(scheduler.get_executions().empty());
+            }
+            AND_WHEN("move time in advance on interval once")
+            {
+                scheduler.time_advance(interval);
+                THEN("observer obtains first value")
+                {
+                    CHECK(mock.get_received_values() == std::vector<size_t>{0});
+                    CHECK(mock.get_on_error_count() == 0);
+                    CHECK(mock.get_on_completed_count() == 0);
+                }
+                THEN("interval schedules schedulable with provided interval")
+                {
+                    CHECK(scheduler.get_schedulings() == std::vector{ initial_time + interval,
+                          initial_time + 2*interval});
+                    CHECK(scheduler.get_executions() == std::vector{initial_time+interval});
+                }
             }
-            THEN("interval schedules schedulable with provided interval")
+            AND_WHEN("move time in advance on interval enough amount of time")
             {
-                CHECK(scheduler.get_schedulings() == std::vector{ s_current_time + interval, s_current_time + 2*interval, s_current_time + 3*interval});
+                for (size_t i = 0; i < 5; ++i)
+                    scheduler.time_advance(interval);
+
+                THEN("observer obtains sequence of values")
+                {
+                    CHECK(mock.get_received_values() == std::vector<size_t>{0, 1, 2});
+                    CHECK(mock.get_on_error_count() == 0);
+                    CHECK(mock.get_on_completed_count() == 1);
+                }
+                THEN("interval schedules schedulable with provided interval")
+                {
+                    CHECK(scheduler.get_executions() == std::vector{ initial_time + interval,
+                          initial_time + 2*interval,
+                          initial_time + 3*interval});
+                    CHECK(scheduler.get_schedulings() == std::vector{ initial_time + interval,
+                          initial_time + 2*interval,
+                          initial_time + 3*interval,
+                          initial_time + 4*interval});
+                }
             }
         }
     }
 
     GIVEN("interval observable with initial delay")
     {
-        auto initial_delay = std::chrono::seconds{ 2 };
-        auto interval = std::chrono::seconds{ 1 };
-        auto obs = rpp::source::interval(initial_delay, interval, scheduler);
+        auto initial_delay = std::chrono::seconds{2};
+        auto interval      = std::chrono::seconds{1};
+        auto obs           = rpp::source::interval(initial_delay, interval, scheduler);
+        auto initial_time  = test_scheduler::worker_strategy::now();
+
         WHEN("subscribe on it via take 3")
         {
             obs.take(3).subscribe(mock);
-            THEN("observer obtains sequence of values")
+            THEN("nothing happens immediately till scheduler advanced")
             {
-                CHECK(mock.get_received_values() == std::vector<size_t>{0, 1, 2});
+                CHECK(mock.get_received_values() == std::vector<size_t>{});
                 CHECK(mock.get_on_error_count() == 0);
-                CHECK(mock.get_on_completed_count() == 1);
+                CHECK(mock.get_on_completed_count() == 0);
+                CHECK(scheduler.get_schedulings() == std::vector{ initial_time + initial_delay});
+                CHECK(scheduler.get_executions().empty());
             }
-            THEN("interval schedules schedulable with provided interval")
+
+            AND_WHEN("move time in advance on interval enough amount of time")
             {
-                CHECK(scheduler.get_schedulings() == std::vector{ s_current_time + initial_delay, s_current_time + initial_delay + interval, s_current_time + initial_delay + 2 * interval });
+                for (size_t i = 0; i < 5; ++i)
+                    scheduler.time_advance(interval);
+                scheduler.time_advance(interval);
+                THEN("observer obtains sequence of values")
+                {
+                    CHECK(mock.get_received_values() == std::vector<size_t>{0, 1, 2});
+                    CHECK(mock.get_on_error_count() == 0);
+                    CHECK(mock.get_on_completed_count() == 1);
+                }
+                THEN("interval schedules schedulable with provided interval")
+                {
+                    CHECK(scheduler.get_schedulings() == std::vector{ initial_time + initial_delay,
+                          initial_time + initial_delay + interval,
+                          initial_time + initial_delay + 2 * interval,
+                          initial_time + initial_delay + 3 * interval });
+                    CHECK(scheduler.get_executions() == std::vector{ initial_time + initial_delay,
+                          initial_time + initial_delay + interval,
+                          initial_time + initial_delay + 2 * interval });
+                }
             }
         }
     }
-}
+}

src/tests/test_observe_on.cpp

@@ -23,6 +23,7 @@ SCENARIO("observe_on transfers emssions to scheduler", "[operators][observe_on]"
 {
     auto mock = mock_observer<std::string>{};
     auto scheduler = test_scheduler{};
+    auto initial_time  = test_scheduler::worker_strategy::now();
 
     GIVEN("observable with item")
     {
@@ -38,7 +39,8 @@ SCENARIO("observe_on transfers emssions to scheduler", "[operators][observe_on]"
 
                 CHECK(mock.get_received_values() == vals);
                 CHECK(mock.get_on_completed_count() == 1);
-                CHECK(scheduler.get_schedulings() == std::vector{ s_current_time, s_current_time, s_current_time });//2 items + on_completed 
+                CHECK(scheduler.get_schedulings() == std::vector{ initial_time, initial_time, initial_time });//2 items + on_completed 
+                CHECK(scheduler.get_executions() == std::vector{ initial_time, initial_time, initial_time });//2 items + on_completed 
             }
         }
     }
@@ -56,7 +58,8 @@ SCENARIO("observe_on transfers emssions to scheduler", "[operators][observe_on]"
 
                 CHECK(mock.get_on_error_count() == 1);
                 CHECK(mock.get_on_completed_count() == 0);
-                CHECK(scheduler.get_schedulings() == std::vector{ s_current_time });
+                CHECK(scheduler.get_schedulings() == std::vector{ initial_time });
+                CHECK(scheduler.get_executions() == std::vector{ initial_time });
 
             }
         }
@@ -76,7 +79,8 @@ SCENARIO("observe_on transfers emssions to scheduler", "[operators][observe_on]"
                 CHECK(mock.get_total_on_next_count() == 0);
                 CHECK(mock.get_on_error_count() == 0);
                 CHECK(mock.get_on_completed_count() == 1);
-                CHECK(scheduler.get_schedulings() == std::vector{ s_current_time });
+                CHECK(scheduler.get_schedulings() == std::vector{ initial_time });
+                CHECK(scheduler.get_executions() == std::vector{ initial_time });
 
             }
         }

src/tests/test_scheduler.hpp

@@ -1,58 +1,96 @@
 //                   ReactivePlusPlus library
-// 
+//
 //           Copyright Aleksey Loginov 2022 - present.
 //  Distributed under the Boost Software License, Version 1.0.
 //     (See accompanying file LICENSE_1_0.txt or copy at
 //           https://www.boost.org/LICENSE_1_0.txt)
-// 
+//
 //  Project home: https://github.com/victimsnino/ReactivePlusPlus
 
 #pragma once
 
 #include <rpp/schedulers.hpp>
 
-static rpp::schedulers::time_point s_current_time{ std::chrono::seconds{0} };
+static rpp::schedulers::time_point s_current_time{std::chrono::seconds{0}};
 
 class test_scheduler final : public rpp::schedulers::details::scheduler_tag
 {
 public:
-    class worker_strategy
+    struct state
     {
-    public:
-        worker_strategy(const rpp::subscription_base& sub,
-            std::shared_ptr<std::vector<rpp::schedulers::time_point>> schedulings)
-            : m_sub{ sub }
-            , m_schedulings{ schedulings } {}
+        state() = default;
+
+        void schedule(rpp::schedulers::time_point                        time_point,
+                      rpp::schedulers::constraint::schedulable_fn auto&& fn)
+        {
+            schedulings.push_back(time_point);
+            queue.emplace(time_point,
+                          static_cast<size_t>(rpp::schedulers::clock_type::now().time_since_epoch().count()),
+                          std::forward<decltype(fn)>(fn));
+        }
 
-        void defer_at(rpp::schedulers::time_point time_point, rpp::schedulers::constraint::schedulable_fn auto&& fn) const
+        void drain()
         {
-            while (m_sub.is_subscribed())
+            while (!queue.empty() && sub.is_subscribed())
             {
-                m_schedulings->push_back(time_point);
+                auto time_point = queue.top().get_time_point();
+                if (time_point > s_current_time)
+                    return;
 
+                auto fn = queue.top().extract_function();
+                queue.pop();
+
+                executions.push_back(s_current_time);
                 if (auto duration = fn())
-                    time_point = std::max(now(), time_point + duration.value());
-                else
-                    return;
+                    schedule(std::max(s_current_time, time_point + duration.value()), std::move(fn));
+            }
+        }
+
+        rpp::subscription_base                   sub{};
+        std::vector<rpp::schedulers::time_point> schedulings{};
+        std::vector<rpp::schedulers::time_point> executions{};
+        std::priority_queue<rpp::schedulers::details::schedulable<std::function<rpp::schedulers::optional_duration()>>> queue{};
+    };
+
+    class worker_strategy
+    {
+    public:
+        worker_strategy(std::shared_ptr<state> state)
+            : m_state{state} { }
+
+        void defer_at(rpp::schedulers::time_point                        time_point,
+                      rpp::schedulers::constraint::schedulable_fn auto&& fn) const
+        {
+            if (m_state->sub.is_subscribed())
+            {
+                m_state->schedule(time_point, std::forward<decltype(fn)>(fn));
+                m_state->drain();
             }
         }
 
         static rpp::schedulers::time_point now() { return s_current_time; }
 
     private:
-        rpp::subscription_base                                    m_sub;
-        std::shared_ptr<std::vector<rpp::schedulers::time_point>> m_schedulings;
+        std::shared_ptr<state> m_state;
     };
 
     test_scheduler() {}
 
     rpp::schedulers::worker<worker_strategy> create_worker(const rpp::subscription_base& sub = {}) const
     {
-        return rpp::schedulers::worker<worker_strategy>{sub, m_schedulings};
+        m_state->sub = sub;
+        return rpp::schedulers::worker<worker_strategy>{m_state};
     }
 
-    const auto& get_schedulings() const { return *m_schedulings; }
+    const auto& get_schedulings() const { return m_state->schedulings; }
+    const auto& get_executions() const { return m_state->executions; }
+
+    void time_advance(rpp::schedulers::duration dur) const
+    {
+        s_current_time += dur;
+        m_state->drain();
+    }
 
 private:
-    std::shared_ptr<std::vector<rpp::schedulers::time_point>> m_schedulings = std::make_shared<std::vector<rpp::schedulers::time_point>>();
-};
+    std::shared_ptr<state> m_state = std::make_shared<state>();
+};

src/tests/test_schedulers.cpp

@@ -64,21 +64,34 @@ SCENARIO("scheduler's worker uses time")
     GIVEN("test scheduler")
     {
         auto scheduler = test_scheduler{};
+        auto initial_time  = test_scheduler::worker_strategy::now();
+
         WHEN("Schedule action without time")
         {
             scheduler.create_worker().schedule([] { return rpp::schedulers::optional_duration{}; });
             THEN("worker obtains schedulable once with current time")
             {
-                CHECK(scheduler.get_schedulings() == std::vector{ s_current_time });
+                CHECK(scheduler.get_schedulings() == std::vector{ initial_time });
+                CHECK(scheduler.get_executions() == std::vector{ initial_time });
             }
         }
         WHEN("Schedule action with some time")
         {
-            auto time = rpp::schedulers::clock_type::now();
-            scheduler.create_worker().schedule(time, [] { return rpp::schedulers::optional_duration{}; });
-            THEN("worker obtains schedulable once with provided time")
+            auto dur = std::chrono::seconds{3};
+            scheduler.create_worker().schedule(initial_time+dur, [] { return rpp::schedulers::optional_duration{}; });
+            THEN("worker obtains schedulable once with provided time, but not execute till time advanced")
             {
-                CHECK(scheduler.get_schedulings() == std::vector{ time });
+                CHECK(scheduler.get_schedulings() == std::vector{ initial_time+dur });
+                CHECK(scheduler.get_executions().empty());
+                AND_WHEN("time advanced")
+                {
+                    scheduler.time_advance(dur+std::chrono::seconds{1});
+                    THEN("scheduler executes schedulable")
+                    {
+                        CHECK(scheduler.get_executions() == std::vector{ initial_time+dur+std::chrono::seconds{1} });
+                    }
+                }
+
             }
         }
         WHEN("Schedule action with zero duration")
@@ -107,9 +120,12 @@ SCENARIO("scheduler's worker uses time")
                         return std::nullopt;
                     return dur;
                 });
+            for(size_t i = 0; i < 3;++i)
+                scheduler.time_advance(dur);
+
             THEN("worker obtains schedulable three times with current time and time+diff")
             {
-                CHECK(scheduler.get_schedulings() == std::vector{ s_current_time, s_current_time + dur , s_current_time + dur + dur });
+                CHECK(scheduler.get_schedulings() == std::vector{ initial_time, initial_time + dur , initial_time + dur + dur });
             }
         }
     }

src/tests/test_subscribe_on.cpp

@@ -21,6 +21,8 @@ TEST_CASE("subscribe_on schedules job in another scheduler")
 {
     auto mock = mock_observer<int>{};
     auto scheduler = test_scheduler{};
+    auto initial_time  = test_scheduler::worker_strategy::now();
+
     GIVEN("observable")
     {
         auto                           obs = rpp::source::create<int>([&](const auto& sub)
@@ -35,7 +37,8 @@ TEST_CASE("subscribe_on schedules job in another scheduler")
             {
                 REQUIRE(mock.get_total_on_next_count() == 1);
                 REQUIRE(mock.get_on_completed_count() == 1);
-                REQUIRE(scheduler.get_schedulings() == std::vector{ s_current_time });
+                REQUIRE(scheduler.get_schedulings() == std::vector{ initial_time });
+                REQUIRE(scheduler.get_executions() == std::vector{ initial_time });
             }
         }
     }
@@ -50,7 +53,8 @@ TEST_CASE("subscribe_on schedules job in another scheduler")
                 REQUIRE(mock.get_total_on_next_count() == 0);
                 REQUIRE(mock.get_on_error_count() == 1);
                 REQUIRE(mock.get_on_completed_count() == 0);
-                REQUIRE(scheduler.get_schedulings() == std::vector{ s_current_time });
+                REQUIRE(scheduler.get_schedulings() == std::vector{ initial_time });
+                REQUIRE(scheduler.get_executions() == std::vector{ initial_time });
             }
         }
     }