Code update for epoch time calculation within DateTimeConverter and enhances unit test coverage by updating relevant test cases

score/datetime_converter/datetime_converter.cpp

@@ -17,6 +17,21 @@ namespace score
 namespace common
 {
 
+static std::int8_t daysInMonth(const std::int16_t year, const std::int8_t month)
+{
+    if (month == 2)
+    {
+        return yearIsLeap(year) ? 29 : 28;
+    }
+
+    if ((month == 4) || (month == 6) || (month == 9) || (month == 11))
+    {
+        return 30;
+    }
+
+    return 31;
+}
+
 int16_t leapYearsSince1970(const int16_t year)
 {
     int16_t numOfLeapYears = (((year - 1969) / 4) - ((year - 1901) / 100)) + ((year - 1601) / 400);
@@ -70,24 +85,7 @@ bool isValidDateTimeFormat(const std::shared_ptr<DateTimeType> dateTime)
         return false;
     }
 
-    if (dateTime->m_month == 2)
-    {
-        if (yearIsLeap(dateTime->m_year))
-        {
-            return (dateTime->m_day <= 29);
-        }
-        else
-        {
-            return (dateTime->m_day <= 28);
-        }
-    }
-
-    if (dateTime->m_month == 4 || dateTime->m_month == 6 || dateTime->m_month == 9 || dateTime->m_month == 11)
-    {
-        return (dateTime->m_day <= 30);
-    }
-
-    return true;
+    return (dateTime->m_day <= daysInMonth(dateTime->m_year, dateTime->m_month));
 };
 
 bool dateTimeToEpoch(const std::shared_ptr<DateTimeType> dateTime, time_t* epoch)
@@ -151,10 +149,6 @@ std::shared_ptr<DateTimeType> epochToDateTime(time_t epoch)
     time_t daysSum = (epoch / SECONDS_PER_DAY) + 1;
     if (before1970)
     {
-        if (yearIsLeap(dateTime->m_year) && ((daysSum * -1) < DAYS_UNTIL_MONTHS[1]))
-        {
-            --daysSum;
-        }
         daysSum = DAYS_PER_YEAR + daysSum - 1;
         if (yearIsLeap(dateTime->m_year))
         {
@@ -200,7 +194,7 @@ std::shared_ptr<DateTimeType> epochToDateTime(time_t epoch)
         }
         else
         {
-            if (daysSum >= DAYS_PER_YEAR)
+            if (daysSum > DAYS_PER_YEAR)
             {
                 dateTime->m_year = dateTime->m_year + 1;
                 daysSum = daysSum - DAYS_PER_YEAR;
@@ -264,6 +258,18 @@ std::shared_ptr<DateTimeType> epochToDateTime(time_t epoch)
             dateTime->m_hour = dateTime->m_hour - HOURS_PER_DAY;
             dateTime->m_day++;
         }
+
+        if (dateTime->m_day == daysInMonth(dateTime->m_year, dateTime->m_month) + 1)
+        {
+            dateTime->m_day = 1;
+            dateTime->m_month++;
+
+            if (dateTime->m_month == 13)
+            {
+                dateTime->m_month = 1;
+                dateTime->m_year++;
+            }
+        }
     }
 
     if (isValidDateTimeFormat(dateTime))

score/datetime_converter/datetime_converter_test.cpp

@@ -453,6 +453,99 @@ TEST_F(DateTimeConverterTest, test_yearIsLeap)
     ASSERT_FALSE(score::common::yearIsLeap(2100));
 }
 
+TEST_F(DateTimeConverterTest, invalid_month_values)
+{
+    RecordProperty("Description", "Verify invalid month values are rejected.");
+    RecordProperty("TestType", "requirements-based");
+
+    auto dtt = std::make_shared<DateTimeType>(2020, 0, 10, 3, 4, 5);
+    ASSERT_FALSE(score::common::isValidDateTimeFormat(dtt));
+
+    dtt->m_month = 13;
+    ASSERT_FALSE(score::common::isValidDateTimeFormat(dtt));
+
+    dtt->m_month = -1;
+    ASSERT_FALSE(score::common::isValidDateTimeFormat(dtt));
+}
+
+TEST_F(DateTimeConverterTest, invalid_day_values)
+{
+    RecordProperty("Description", "Verify invalid day values are rejected.");
+    RecordProperty("TestType", "requirements-based");
+
+    auto dtt = std::make_shared<DateTimeType>(2020, 12, 34, 3, 4, 5);
+    ASSERT_FALSE(score::common::isValidDateTimeFormat(dtt));
+
+    dtt->m_day = -1;
+    ASSERT_FALSE(score::common::isValidDateTimeFormat(dtt));
+}
+
+TEST_F(DateTimeConverterTest, dateTimeToEpoch_false_isValidDateTimeFormat)
+{
+    RecordProperty("Description", "Verify dateTimeToEpoch returns false for invalid DateTime input.");
+    RecordProperty("TestType", "requirements-based");
+
+    time_t epoch = static_cast<time_t>(0x7F7F7F7F);
+
+    // Invalid: month = 13 -> isValidDateTimeFormat returns false
+    auto d = std::make_shared<DateTimeType>(2024, 13, 10, 12, 30, 45);
+
+    ASSERT_FALSE(score::common::dateTimeToEpoch(d, &epoch));
+
+    ASSERT_EQ(epoch, static_cast<time_t>(0x7F7F7F7F));
+}
+
+TEST_F(DateTimeConverterTest, EpochToDateTime_Post1970_NonLeapYear_YearRollover)
+{
+    RecordProperty("Description",
+        "Verify that a post-1970 epoch landing exactly on a non-leap year boundary rolls over to the next year correctly.");
+    RecordProperty("TestType", "requirements-based");
+
+    time_t epoch{};
+    auto dateTimeOriginal = std::make_shared<DateTimeType>(1971, 1, 1, 0, 0, 0);
+    ASSERT_TRUE(score::common::dateTimeToEpoch(dateTimeOriginal, &epoch));
+
+    auto dateTimeConverted = score::common::epochToDateTime(epoch);
+    ASSERT_NE(dateTimeConverted, nullptr);
+    ASSERT_EQ(dateTimeConverted->m_year, 1971);
+    ASSERT_EQ(dateTimeConverted->m_month, 1);
+    ASSERT_EQ(dateTimeConverted->m_day, 1);
+    ASSERT_EQ(dateTimeConverted->m_hour, 0);
+    ASSERT_EQ(dateTimeConverted->m_minute, 0);
+    ASSERT_EQ(dateTimeConverted->m_second, 0);
+}
+
+TEST_F(DateTimeConverterTest, EpochToDateTime_Pre1970_YearBoundary_DayOverflowRollover)
+{
+    RecordProperty("Description",
+        "Verify that pre-1970 conversion handles day overflow at year boundary by rolling month and year.");
+    RecordProperty("TestType", "requirements-based");
+
+    // 1960-01-01 00:00:00 epoch; this path normalizes an intermediate Dec 32 to Jan 1 of the next year.
+    const time_t epochAt1960Start = static_cast<time_t>(-315619200);
+
+    auto dateTimeConverted = score::common::epochToDateTime(epochAt1960Start);
+    ASSERT_NE(dateTimeConverted, nullptr);
+    EXPECT_EQ(dateTimeConverted->m_year, 1960);
+    EXPECT_EQ(dateTimeConverted->m_month, 1);
+    EXPECT_EQ(dateTimeConverted->m_day, 1);
+    EXPECT_EQ(dateTimeConverted->m_hour, 0);
+    EXPECT_EQ(dateTimeConverted->m_minute, 0);
+    EXPECT_EQ(dateTimeConverted->m_second, 0);
+}
+
+TEST_F(DateTimeConverterTest, EpochToDateTime_OutOfRangeUpperBound_ReturnsNullptr)
+{
+    RecordProperty("Description",
+        "Verify that epoch values mapping above the supported year range return nullptr.");
+    RecordProperty("TestType", "requirements-based");
+
+    // This epoch maps to year 10000, which is above the supported upper bound (9999).
+    const time_t epochOutOfRange = static_cast<time_t>(253405000000);
+
+    auto dateTimeConverted = score::common::epochToDateTime(epochOutOfRange);
+    EXPECT_EQ(dateTimeConverted, nullptr);
+}
 }  // namespace testing
 }  // namespace platform
 }  // namespace score