Add tests to check the time formatting of the series builder

Author: Enric Sala

tests/SeriesTest.m

@@ -200,6 +200,37 @@ function skips_nonfinite_samples(test)
             exp = 'weather temperature=24.3 1529933525520';
             test.verifyEqual(s.toLine(), exp);
         end
+        
+        function time_is_added_in_millis_by_default(test)
+            millis = 1529933525520;
+            time = datetime(millis / 1000, 'ConvertFrom', 'posixtime');
+            s = Series('weather') ...
+                .fields('temperature', 24.3) ...
+                .time(time);
+            exp = 'weather temperature=24.3 1529933525520';
+            test.verifyEqual(s.toLine(), exp);
+        end
+        
+        function time_supports_different_precisions(test)
+            millis = 1529933525520;
+            time = datetime(millis / 1000, 'ConvertFrom', 'posixtime');
+            s = Series('weather') ...
+                .fields('temperature', 24.3);
+            precisions = struct( ...
+                'ns', '1529933525520000000', ...
+                'u', '1529933525520000', ...
+                'ms', '1529933525520', ...
+                's', '1529933526', ...
+                'm', '25498892', ...
+                'h', '424982');
+            names = fieldnames(precisions);
+            for i = 1:length(names)
+                name = names{i};
+                exp = [' ', precisions.(name)];
+                line = s.time(time).toLine(name);
+                test.verifyTrue(endsWith(line, exp));
+            end
+        end
     end
 
 end