More tests, seems to be working. Still needs to handle non-existent dates.

.idea/runConfigurations/All.xml

@@ -0,0 +1,6 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All" type="CMakeCatchTestRunConfigurationType" factoryName="Catch Test" singleton="true" PASS_PARENT_ENVS_2="true" PROJECT_NAME="Project" TARGET_NAME="cron_test" CONFIG_NAME="Debug" RUN_TARGET_PROJECT_NAME="Project" RUN_TARGET_NAME="cron_test" TEST_MODE="SUITE_TEST">
+    <envs />
+    <method />
+  </configuration>
+</component>

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.9)
+cmake_minimum_required(VERSION 3.6)
 
 add_subdirectory(libcron)
 add_subdirectory(test)

libcron/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.9)
+cmake_minimum_required(VERSION 3.6)
 project(libcron)
 
 set(CMAKE_CXX_STANDARD 14)

libcron/CronSchedule.cpp

@@ -9,9 +9,12 @@ namespace libcron
     std::chrono::system_clock::time_point
     CronSchedule::calculate_from(const std::chrono::system_clock::time_point& from)
     {
-        auto curr = from;
+        //auto time_part = from - date::floor<days>(from);
+        auto curr = from;// - time_part;
+        //auto dt = to_calendar_time(curr);
 
         bool done = false;
+
         while (!done)
         {
             year_month_day ymd = date::floor<days>(curr);
@@ -19,23 +22,24 @@ namespace libcron
             // Add months until one of the allowed days are found, or stay at the current one.
             if (data.get_months().find(static_cast<Months>(unsigned(ymd.month()))) == data.get_months().end())
             {
-                curr += months{1};
+                auto next_month = ymd + months{1};
-                ymd = date::floor<days>(curr);
+                sys_days s = next_month.year() / next_month.month() / 1;
+                curr = s;
                 continue;
             }
-
                 // If all days are allowed, then the 'day of week' takes precedence, which also means that
                 // day of week only is ignored when specific days of months are specified.
-            if (data.get_day_of_month().size() != CronData::value_of(DayOfMonth::Last))
+            else if (data.get_day_of_month().size() != CronData::value_of(DayOfMonth::Last))
             {
                 // Add days until one of the allowed days are found, or stay at the current one.
-                if(data.get_day_of_month().find(static_cast<DayOfMonth>(unsigned(ymd.day()))) ==
+                if (data.get_day_of_month().find(static_cast<DayOfMonth>(unsigned(ymd.day()))) ==
                     data.get_day_of_month().end())
                 {
+                    sys_days s = ymd;
+                    curr = s;
                     curr += days{1};
-                    ymd = date::floor<days>(curr);
                     continue;
-                };
+                }
             }
             else
             {
@@ -45,30 +49,27 @@ namespace libcron
                 if (data.get_day_of_week().find(static_cast<DayOfWeek>(unsigned(ymw.weekday()))) ==
                     data.get_day_of_week().end())
                 {
+                    sys_days s = ymd;
+                    curr = s;
                     curr += days{1};
-                    ymw = date::floor<days>(curr);
                     continue;
-                };
+                }
             }
 
-            // Add hours until the current hour is one of the allowed
+            //curr += time_part;
             auto date_time = to_calendar_time(curr);
             if (data.get_hours().find(static_cast<Hours>(date_time.hour)) == data.get_hours().end())
             {
                 curr += hours{1};
-                continue;
+                curr -= minutes{date_time.min};
+                curr -= seconds{date_time.sec};
             }
             else if (data.get_minutes().find(static_cast<Minutes >(date_time.min)) == data.get_minutes().end())
             {
                 curr += minutes{1};
-                continue;
+                curr -= seconds{date_time.sec};
             }
             else if (data.get_seconds().find(static_cast<Seconds>(date_time.sec)) == data.get_seconds().end())
-            {
-                curr += seconds{1};
-                continue;
-            }
-            else if( curr <= from )
             {
                 curr += seconds{1};
             }
@@ -78,7 +79,6 @@ namespace libcron
             }
         }
 
-
         return curr;
     }
 }

test/CMakeLists.txt

@@ -13,6 +13,6 @@ include_directories(
 add_executable(
         ${PROJECT_NAME}
         test.cpp
-)
+        CronScheduleTest.cpp)
 
 target_link_libraries(${PROJECT_NAME} libcron)

test/CronScheduleTest.cpp

@@ -0,0 +1,66 @@
+#include <catch.hpp>
+#include <chrono>
+#include <date.h>
+#include <libcron/Cron.h>
+#include <iostream>
+
+using namespace libcron;
+using namespace date;
+using namespace std::chrono;
+
+system_clock::time_point DT(year_month_day ymd, hours h = hours{0}, minutes m = minutes{0}, seconds s = seconds{0})
+{
+    sys_days t = ymd;
+    auto sum = t + h + m + s;
+    return sum;
+}
+
+bool test(const std::string& schedule, system_clock::time_point from, system_clock::time_point expected_next)
+{
+    auto c = CronData::create(schedule);
+    bool res = c.is_valid();
+    if (res)
+    {
+        CronSchedule sched(c);
+        auto run_time = sched.calculate_from(from);
+        res &= expected_next == run_time;
+
+        if (!res)
+        {
+            std::cout
+                    << "From:       " << from << "\n"
+                    << "Expected:   " << expected_next << "\n"
+                    << "Calculated: " << run_time;
+
+        }
+    }
+
+    return res;
+}
+
+
+SCENARIO("Calculating next runtime")
+{
+    REQUIRE(test("0 0 * * * *", DT(2010_y / 1 / 1), DT(2010_y / 1 / 1, hours{0})));
+    REQUIRE(test("0 0 * * * *", DT(2010_y / 1 / 1, hours{0}, minutes{0}, seconds{1}), DT(2010_y / 1 / 1, hours{1})));
+    REQUIRE(test("0 0 * * * *", DT(2010_y / 1 / 1, hours{5}), DT(2010_y / 1 / 1, hours{5})));
+    REQUIRE(test("0 0 * * * *", DT(2010_y / 1 / 1, hours{5}, minutes{1}), DT(2010_y / 1 / 1, hours{6})));
+    REQUIRE(test("0 0 * * * *", DT(2017_y / 12 / 31, hours{23}, minutes{59}, seconds{58}), DT(2018_y / 1 / 1, hours{0})));
+    REQUIRE(test("0 0 10 * * *", DT(2017_y / 12 / 31, hours{9}, minutes{59}, seconds{58}), DT(2017_y / 12 / 31, hours{10})));
+    REQUIRE(test("0 0 10 * * *", DT(2017_y / 12 / 31, hours{23}, minutes{59}, seconds{58}), DT(2018_y / 1 / 1, hours{10})));
+    REQUIRE(test("0 0 10 * FEB *", DT(2017_y / 12 / 31, hours{23}, minutes{59}, seconds{58}), DT(2018_y / 2 / 1, hours{10})));
+    REQUIRE(test("0 0 10 25 FEB *", DT(2017_y / 12 / 31, hours{23}, minutes{59}, seconds{58}), DT(2018_y / 2 / 25, hours{10})));
+    REQUIRE(test("0 0 10 * FEB 1", DT(2017_y / 12 / 31, hours{23}, minutes{59}, seconds{58}), DT(year_month_day{2018_y/2/mon[1]}, hours{10})));
+    REQUIRE(test("0 0 10 * FEB 6", DT(2017_y / 12 / 31, hours{23}, minutes{59}, seconds{58}), DT(year_month_day{2018_y/2/sat[1]}, hours{10})));
+    REQUIRE(test("* * * 10-12 NOV *", DT(2018_y / 11 / 11, hours{10}, minutes{11}, seconds{12}), DT(year_month_day{2018_y/11/11}, hours{10}, minutes{11}, seconds{12})));
+}
+
+SCENARIO("Leap year")
+{
+    REQUIRE(test("0 0 * 29 FEB *", DT(2018_y / 1 / 1), DT(2020_y / 2 / 29)));
+}
+
+SCENARIO("Date that does not exist")
+{
+    //REQUIRE_FALSE(test("0 0 * 30 FEB *", DT(2018_y / 1 / 1), DT(2020_y / 2 / 29)));
+}

test/test.cpp

@@ -227,53 +227,3 @@ SCENARIO("Using step syntax")
     }
 }
 
-SCENARIO("Calculating next runtime")
-{
-    GIVEN("An item schedule for the top of every hour")
-    {
-        auto c = CronData::create("0 0 * * * *");
-        REQUIRE(c.is_valid());
-        CronSchedule sched(c);
-
-        WHEN("Start time is midnight")
-        {
-            sys_days midnight = 2010_y/1/1;
-            std::chrono::system_clock::time_point run_time = sched.calculate_from(midnight);
-
-            THEN("Next runtime is 01:00 of the same date")
-            {
-                auto t = CronSchedule::to_calendar_time(run_time);
-                REQUIRE(t.year == 2010);
-                REQUIRE(t.month == 1);
-                REQUIRE(t.day == 1);
-                REQUIRE(t.hour == 1);
-                REQUIRE(t.min == 0);
-                REQUIRE(t.sec == 0);
-            }
-        }
-        AND_WHEN("Start time 05:00:00")
-        {
-            sys_days midnight = 2010_y/1/1;
-            system_clock::time_point five = midnight;
-            five += hours{5};
-
-            auto t2 = CronSchedule::to_calendar_time(five);
-
-            std::chrono::system_clock::time_point run_time = sched.calculate_from(five);
-
-            THEN("Next runtime is 06:00 of the same date")
-            {
-                auto t = CronSchedule::to_calendar_time(run_time);
-                REQUIRE(t.year == 2010);
-                REQUIRE(t.month == 1);
-                REQUIRE(t.day == 1);
-                REQUIRE(t.hour == 6);
-                REQUIRE(t.min == 0);
-                REQUIRE(t.sec == 0);
-            }
-        }
-
-
-
-    }
-}