Fix to_string(time_t) and write a unit test for it

2 files changed, 15 insertions, 4 deletions

diff --git a/louloulibs/utils/time.cpp b/louloulibs/utils/time.cpp
index e23def4..b85d764 100644
--- a/louloulibs/utils/time.cpp
+++ b/louloulibs/utils/time.cpp
@@ -4,9 +4,10 @@ namespace utils
 {
 std::string to_string(const std::time_t& timestamp)
 {
-    constexpr std::size_t stamp_size = 20;
-    char date_buf[stamp_size];
-    std::strftime(date_buf, stamp_size, "%FT%TZ", std::gmtime(&timestamp));
-    return {std::begin(date_buf), std::end(date_buf)};
+  constexpr std::size_t stamp_size = 21;
+  char date_buf[stamp_size];
+  if (std::strftime(date_buf, stamp_size, "%FT%TZ", std::gmtime(&timestamp)) != stamp_size - 1)
+    return "";
+  return {std::begin(date_buf), std::end(date_buf) - 1};
 }
 }
\ No newline at end of file
diff --git a/tests/utils.cpp b/tests/utils.cpp
index e7ba415..abe7ef7 100644
--- a/tests/utils.cpp
+++ b/tests/utils.cpp
@@ -7,6 +7,7 @@
 #include <utils/xdg.hpp>
 #include <utils/empty_if_fixed_server.hpp>
 #include <utils/get_first_non_empty.hpp>
+#include <utils/time.hpp>
 
 using namespace std::string_literals;
 
@@ -111,3 +112,12 @@ TEST_CASE("first non-empty string")
   CHECK(get_first_non_empty("first"s) == "first"s);
   CHECK(get_first_non_empty(0, 1, 2, 3) == 1);
 }
+
+TEST_CASE("time_to_string")
+{
+  const std::time_t stamp = 1472480968;
+  const std::string result = "2016-08-29T14:29:28Z";
+  CHECK(utils::to_string(stamp) == result);
+  CHECK(utils::to_string(stamp).size() == result.size());
+  CHECK(utils::to_string(0) == "1970-01-01T00:00:00Z");
+}