1 files changed, 54 insertions, 0 deletions
diff --git a/tests/libntp/tvtots.c b/tests/libntp/tvtots.c
new file mode 100644
index 000000000000..6c8345aaaa1b
--- /dev/null
+++ b/tests/libntp/tvtots.c
@@ -0,0 +1,54 @@
+#include "config.h"
+
+#include "lfptest.h"
+#include "timevalops.h"
+
+#include "unity.h"
+#include <math.h>// Required on Solaris for ldexp.
+
+
+void test_Seconds(void)
+{
+	struct timeval input = {500, 0}; // 500.0 s
+	l_fp expected = {500, 0};
+	l_fp actual;
+
+	TVTOTS(&input, &actual);
+
+	TEST_ASSERT_TRUE(IsEqual(expected, actual));
+}
+
+void test_MicrosecondsRounded(void)
+{
+	/* 0.0005 can not be represented exact in a l_fp structure.
+	 * It would equal to 2147483,648. This means that
+	 * HALF_PROMILLE_UP (which is 2147484) should be
+	 * the correct rounding. */
+
+	struct timeval input = {0, 500}; // 0.0005 exact
+	l_fp expected = {0, HALF_PROMILLE_UP};
+	l_fp actual;
+
+	TVTOTS(&input, &actual);
+	TEST_ASSERT_TRUE(IsEqual(expected, actual));
+}
+
+void test_MicrosecondsExact(void)
+{
+	// 0.5 can be represented exact in both l_fp and timeval.
+	const struct timeval input = {10, 500000}; // 0.5 exact
+	const l_fp expected = {10, HALF}; // 0.5 exact
+	l_fp actual;
+
+	TVTOTS(&input, &actual);
+
+	// Compare the fractional part with an absolute error given.
+	TEST_ASSERT_EQUAL_UINT(expected.l_ui, actual.l_ui);
+
+	double expectedDouble, actualDouble;
+	M_LFPTOD(0, expected.l_uf, expectedDouble);
+	M_LFPTOD(0, actual.l_uf, actualDouble);
+
+	// The error should be less than 0.5 us
+	TEST_ASSERT_DOUBLE_WITHIN(0000005, expectedDouble, actualDouble);
+}