Add test for mktime and localtime (esp8266#1745)

Author: igrr

tests/device/test_time/test_time.ino

@@ -35,12 +35,41 @@ TEST_CASE("Can sync time", "[time]")
         delay(100);
     }
     {
-      time_t now = time(nullptr);
-      Serial.println(ctime(&now));
+        time_t now = time(nullptr);
+        Serial.println(ctime(&now));
     }
     CHECK(false);
 }
 
+TEST_CASE("#1745 mktime and localtime", "[time]")
+{
+    struct tm tm_in;
+    struct tm tm_out;
+
+    const int years[] = {2012, 2013, 2014};
+    const time_t timestamps[] = {1332640800, 1364176800, 1395712800};
+
+    for (int i = 0; i < sizeof(years)/sizeof(years[0]); ++i) {
+        tm_in.tm_year = years[i] - 1900;
+        tm_in.tm_mon = 2;
+        tm_in.tm_mday = 25;
+        tm_in.tm_hour = 2;
+        tm_in.tm_min = 0;
+        tm_in.tm_sec = 0;
+        tm_in.tm_wday = 0;
+        time_t ts = mktime(&tm_in);
+        CHECK(ts == timestamps[i]);
+        localtime_r(&ts, &tm_out);
+        CHECK(tm_in.tm_year == tm_out.tm_year);
+        CHECK(tm_in.tm_mon  == tm_out.tm_mon );
+        CHECK(tm_in.tm_mday == tm_out.tm_mday);
+        CHECK(tm_in.tm_hour == tm_out.tm_hour);
+        CHECK(tm_in.tm_min  == tm_out.tm_min );
+        CHECK(tm_in.tm_sec  == tm_out.tm_sec );
+        CHECK(tm_in.tm_wday == tm_out.tm_wday);
+    }
+}
+
 void loop()
 {
 }