1 files changed, 118 insertions, 1 deletions
diff --git a/difftimespec.c b/difftimespec.c
index 383dced..07f46c9 100644
--- a/difftimespec.c
+++ b/difftimespec.c
@@ -1,9 +1,10 @@
 /* See LICENSE file for copyright and license details. */
 #include "libsimple.h"
+#ifndef TEST
 
 
 int
-libsimple_difftimespec(struct timespec *diff, const struct timespec *minuend, const struct timespec *subtrahend) /* TODO test */
+libsimple_difftimespec(struct timespec *diff, const struct timespec *minuend, const struct timespec *subtrahend)
 {
 	long int ns = minuend->tv_nsec - subtrahend->tv_nsec;
 	time_t s;
@@ -48,3 +49,119 @@ libsimple_difftimespec(struct timespec *diff, const struct timespec *minuend, co
 	diff->tv_nsec = ns;
 	return ret;
 }
+
+
+#else
+#include "test.h"
+
+int
+main(void)
+{
+	struct timespec r, a, b;
+
+	a.tv_sec = 0, a.tv_nsec = 0L;
+	b.tv_sec = 0, b.tv_nsec = 0L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == 0);
+	assert(r.tv_nsec == 0L);
+
+	a.tv_sec = 10, a.tv_nsec = 0L;
+	b.tv_sec =  0, b.tv_nsec = 0L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == 10);
+	assert(r.tv_nsec == 0L);
+
+	a.tv_sec = 10, a.tv_nsec = 100L;
+	b.tv_sec =  0, b.tv_nsec =   0L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == 10);
+	assert(r.tv_nsec == 100L);
+
+	a.tv_sec = 10, a.tv_nsec = 100L;
+	b.tv_sec =  1, b.tv_nsec =   0L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == 9);
+	assert(r.tv_nsec == 100L);
+
+	a.tv_sec = 10, a.tv_nsec = 100L;
+	b.tv_sec =  0, b.tv_nsec =   1L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == 10);
+	assert(r.tv_nsec == 99L);
+
+	a.tv_sec = -10, a.tv_nsec = 100L;
+	b.tv_sec =   0, b.tv_nsec =   0L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == -10);
+	assert(r.tv_nsec == 100L);
+
+	a.tv_sec = 10, a.tv_nsec =   1L;
+	b.tv_sec =  1, b.tv_nsec = 100L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == 8);
+	assert(r.tv_nsec == 1000000001L - 100L);
+
+	a.tv_sec = 10, a.tv_nsec = 0L;
+	b.tv_sec = 20, b.tv_nsec = 0L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == -10);
+	assert(r.tv_nsec == 0L);
+
+	a.tv_sec = 10, a.tv_nsec = 10L;
+	b.tv_sec = 20, b.tv_nsec =  0L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == -10);
+	assert(r.tv_nsec == 10L);
+
+	a.tv_sec = 10, a.tv_nsec = 10L;
+	b.tv_sec = 20, b.tv_nsec = 20L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == -10 - 1);
+	assert(r.tv_nsec == 1000000010L - 20L);
+
+	a.tv_sec =  10, a.tv_nsec = 10L;
+	b.tv_sec = -20, b.tv_nsec =  0L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == 30);
+	assert(r.tv_nsec == 10L);
+
+	a.tv_sec = 0, a.tv_nsec = 10L;
+	b.tv_sec = 0, b.tv_nsec =  0L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == 0);
+	assert(r.tv_nsec == 10L);
+
+	a.tv_sec = 0, a.tv_nsec =  0L;
+	b.tv_sec = 0, b.tv_nsec = 10L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == -1);
+	assert(r.tv_nsec == 1000000000L - 10L);
+
+	a.tv_sec = TIME_MIN, a.tv_nsec = 0L;
+	b.tv_sec = 0,        b.tv_nsec = 0L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == TIME_MIN);
+	assert(r.tv_nsec == 0L);
+
+	a.tv_sec = TIME_MIN, a.tv_nsec = 0L;
+	b.tv_sec = 0,        b.tv_nsec = 1L;
+	assert(libsimple_difftimespec(&r, &a, &b) == -1 && errno == ERANGE);
+	assert(r.tv_sec  == TIME_MIN);
+	assert(r.tv_nsec == 0L);
+
+	a.tv_sec = TIME_MIN, a.tv_nsec = 0L;
+	b.tv_sec = -1,       b.tv_nsec = 1L;
+	assert(!libsimple_difftimespec(&r, &a, &b));
+	assert(r.tv_sec  == TIME_MIN);
+	assert(r.tv_nsec == 999999999L);
+
+	a.tv_sec = TIME_MAX, a.tv_nsec = 0L;
+	b.tv_sec = -1,       b.tv_nsec = 0L;
+	assert(libsimple_difftimespec(&r, &a, &b) == -1 && errno == ERANGE);
+	assert(r.tv_sec  == TIME_MAX);
+	assert(r.tv_nsec == 999999999L);
+
+	return 0;
+}
+
+#endif