add ambigious handling + add tests

Signed-off-by: hamzah <hamzah.chaudhry@proton.me>

Author: hamzahchaudhry

src/Datetime.cpp

@@ -166,7 +166,8 @@ bool Datetime::parse (
     return true;
   }
 
-  if (parse_formatted (pig, format))
+  bool ambiguous {false};
+  if (parse_formatted (pig, format, ambiguous))
   {
     // Check the values and determine time_t.
     if (validate ())
@@ -176,6 +177,10 @@ bool Datetime::parse (
       return true;
     }
   }
+  else if (ambiguous)
+  {
+    return false;
+  }
 
   // Allow parse_date_time and parse_date_time_ext regardless of
   // Datetime::isoEnabled setting, because these formats are relied upon by
@@ -232,7 +237,7 @@ void Datetime::clear ()
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-bool Datetime::parse_formatted (Pig& pig, const std::string& format)
+bool Datetime::parse_formatted (Pig& pig, const std::string& format, bool& ambiguous)
 {
   // Short-circuit on missing format.
   if (format.empty ())
@@ -247,6 +252,7 @@ bool Datetime::parse_formatted (Pig& pig, const std::string& format)
   int minute {-1};
   int second {-1};
   int meridiem {-1};
+  bool twelveHourTime {false};
 
   // For parsing, unused.
   int wday   {-1};
@@ -355,6 +361,7 @@ bool Datetime::parse_formatted (Pig& pig, const std::string& format)
       break;
 
     case 'i':
+      twelveHourTime = true;
       if (pig.getDigit (hour))
       {
         if (hour == 0)
@@ -381,6 +388,7 @@ bool Datetime::parse_formatted (Pig& pig, const std::string& format)
       break;
 
     case 'I':
+      twelveHourTime = true;
       if (! pig.getDigit2 (hour) || hour < 1 || hour > 12)
       {
         pig.restoreTo (checkpoint);
@@ -592,6 +600,13 @@ bool Datetime::parse_formatted (Pig& pig, const std::string& format)
   if (minute == -1) minute = 0;
   if (second == -1) second = 0;
 
+  if (twelveHourTime && meridiem == -1)
+  {
+    ambiguous = true;
+    pig.restoreTo (checkpoint);
+    return false;
+  }
+
   if (meridiem != -1)
   {
     if (hour < 1 || hour > 12)

src/Datetime.h

@@ -116,7 +116,7 @@ class Datetime
 
 private:
   void clear ();
-  bool parse_formatted     (Pig&, const std::string&);
+  bool parse_formatted     (Pig&, const std::string&, bool& ambiguous);
   bool parse_named         (Pig&);
   bool parse_epoch         (Pig&);
   bool parse_date_time_ext (Pig&);

test/datetime.t.cpp

@@ -1070,6 +1070,9 @@ int main (int, char**)
     t.is (Datetime::length ("V"), 2,  "length 'V' --> 2");
     t.is (Datetime::length ("h"), 2,  "length 'h' --> 2");
     t.is (Datetime::length ("H"), 2,  "length 'H' --> 2");
+    t.is (Datetime::length ("i"), 2,  "length 'i' --> 2");
+    t.is (Datetime::length ("I"), 2,  "length 'I' --> 2");
+    t.is (Datetime::length ("p"), 2,  "length 'p' --> 2");
     t.is (Datetime::length ("n"), 2,  "length 'n' --> 2");
     t.is (Datetime::length ("N"), 2,  "length 'N' --> 2");
     t.is (Datetime::length ("s"), 2,  "length 's' --> 2");
@@ -1095,6 +1098,9 @@ int main (int, char**)
     t.is (r32.toString ("d"),        "28", "2015-10-28T12:55:01 -> d ->        28");
     t.is (r32.toString ("H"),        "12", "2015-10-28T12:55:01 -> H ->        12");
     t.is (r32.toString ("h"),        "12", "2015-10-28T12:55:01 -> h ->        12");
+    t.is (r32.toString ("I"),        "12", "2015-10-28T12:55:01 -> I ->        12");
+    t.is (r32.toString ("i"),        "12", "2015-10-28T12:55:01 -> i ->        12");
+    t.is (r32.toString ("p"),        "PM", "2015-10-28T12:55:01 -> p ->        PM");
     t.is (r32.toString ("N"),        "55", "2015-10-28T12:55:01 -> N ->        55");
     t.is (r32.toString ("n"),        "55", "2015-10-28T12:55:01 -> n ->        55");
     t.is (r32.toString ("S"),        "00", "2015-10-28T12:55:01 -> S ->        01");
@@ -1109,6 +1115,16 @@ int main (int, char**)
     t.is (r32.toString ("j"),       "301", "2015-10-28T12:55:01 -> j ->       301");
     t.is (r32.toString ("w"),         "3", "2015-10-28T12:55:01 -> w ->         3");
 
+    Datetime r32a ("2015-10-28T00:05:00");
+    t.is (r32a.toString ("I"),       "12", "2015-10-28T00:05:00 -> I ->        12");
+    t.is (r32a.toString ("i"),       "12", "2015-10-28T00:05:00 -> i ->        12");
+    t.is (r32a.toString ("p"),       "AM", "2015-10-28T00:05:00 -> p ->        AM");
+
+    Datetime r32b ("2015-10-28T13:05:00");
+    t.is (r32b.toString ("I"),       "01", "2015-10-28T13:05:00 -> I ->        01");
+    t.is (r32b.toString ("i"),        "1", "2015-10-28T13:05:00 -> i ->         1");
+    t.is (r32b.toString ("p"),       "PM", "2015-10-28T13:05:00 -> p ->        PM");
+
     // Test all parse options.
     Datetime r33 ("2015 10 28 19 28 01", "Y M D H N S");
     t.is(r33.year (),   2015,         "Y works");
@@ -1126,6 +1142,24 @@ int main (int, char**)
     t.is(r34.minute (),    2,         "n works");
     t.is(r34.second (),    1,         "s works");
 
+    Datetime r34a ("2015 10 28 12 00 AM", "Y M D I N p");
+    t.is(r34a.hour (),      0,         "12 AM parses as hour 0");
+    t.is(r34a.minute (),    0,         "12 AM minute works");
+
+    Datetime r34b ("2015 10 28 12 00 PM", "Y M D I N p");
+    t.is(r34b.hour (),     12,         "12 PM parses as hour 12");
+    t.is(r34b.minute (),    0,         "12 PM minute works");
+
+    Datetime r34c ("2015 10 28 1 30 PM", "Y M D i N p");
+    t.is(r34c.hour (),     13,         "1 PM parses as hour 13");
+    t.is(r34c.minute (),   30,         "1 PM minute works");
+
+    Datetime r34d ("2015 10 28 11 45 pm", "Y M D i N p");
+    t.is(r34d.hour (),     23,         "lowercase pm parses as hour 23");
+    t.is(r34d.minute (),   45,         "lowercase pm minute works");
+
+    t.notok (Datetime::valid ("2015_10_28_1_30", "Y_M_D_i_N"), "ambiguous 12-hour time without AM/PM is invalid");
+
     Datetime r35 ("Wednesday October 28 2015", "A B D Y");
     t.is(r35.year (),    2015,        "Y works");
     t.is(r35.month (),     10,        "B works");