Make sure timestamp is read back correctly (#68)

* Make sure timestamp is read back correctly

* Add fix to parsing timestamp when query

src/InfluxDB.cxx

@@ -104,7 +104,7 @@ std::vector<Point> InfluxDB::query(const std::string&  query)
             std::tm tm = {};
             std::stringstream ss;
             ss << value;
-            ss >> std::get_time(&tm, "%FT%TZ");
+            ss >> std::get_time(&tm, "%Y-%m-%dT%H:%M:%SZ");
             point.setTimestamp(std::chrono::system_clock::from_time_t(std::mktime(&tm)));
             continue;
           }

test/testQuery.cxx

@@ -1,7 +1,6 @@
 #define BOOST_TEST_MODULE Test InfluxDB Query
 #define BOOST_TEST_DYN_LINK
 #include <boost/test/unit_test.hpp>
-
 #include "../include/InfluxDBFactory.h"
 #include "../src/InfluxDBException.h"
 
@@ -26,6 +25,21 @@ BOOST_AUTO_TEST_CASE(query1)
   BOOST_CHECK_EQUAL(points[2].getTags(), "host=localhost");
 }
 
+BOOST_AUTO_TEST_CASE(timeStampVerify)
+{
+  double timeZone = 3600; //+1h
+
+  auto influxdb = influxdb::InfluxDBFactory::Get("http://localhost:8086?db=test");
+  Point point = Point{"timestampCheck"}.addField("value", 10);
+  auto timestamp = point.getTimestamp();
+  influxdb->write(std::move(point));
+
+  auto points = influxdb->query("SELECT * from timestampCheck ORDER BY DESC LIMIT 1");
+  std::chrono::duration<double> diff = timestamp - points[0].getTimestamp();
+  double diffZone = diff.count() - timeZone;
+  BOOST_CHECK(diffZone < 1); // 1s
+}
+
 BOOST_AUTO_TEST_CASE(failedQuery1)
 {
   auto influxdb = influxdb::InfluxDBFactory::Get("http://localhost:8086?db=test");