tests: add tests for time-util.c

add tests for:
- timezone_is_valid
- get_timezones

src/test/test-time.c

@@ -20,6 +20,7 @@
 ***/
 
 #include "time-util.h"
+#include "strv.h"
 
 static void test_parse_sec(void) {
         usec_t u;
@@ -126,11 +127,33 @@ static void test_format_timespan(usec_t accuracy) {
         test_format_timespan_one(9*USEC_PER_YEAR/5 - 23, accuracy);
 }
 
+static void test_timezone_is_valid(void) {
+        assert_se(timezone_is_valid("Europe/Berlin"));
+        assert_se(timezone_is_valid("Australia/Sydney"));
+        assert_se(!timezone_is_valid("Europe/Do not exist"));
+}
+
+static void test_get_timezones(void) {
+        _cleanup_strv_free_ char **zones = NULL;
+        int r;
+        char **zone;
+
+        r = get_timezones(&zones);
+        assert_se(r == 0);
+
+        STRV_FOREACH(zone, zones) {
+                assert_se(timezone_is_valid(*zone));
+        }
+}
+
 int main(int argc, char *argv[]) {
         test_parse_sec();
         test_parse_nsec();
         test_format_timespan(1);
         test_format_timespan(USEC_PER_MSEC);
         test_format_timespan(USEC_PER_SEC);
+        test_timezone_is_valid();
+        test_get_timezones();
+
         return 0;
 }