Fix mapping of interval for the day of week

It fixes how the mapper handle the day of the week, leaving the interval untouched, but mapping the start day if present.
Also fixes the int mapping when parsing. In unix "7/3" should be parsed as "0/3"

Fixes #495

Author: hibnico

src/main/java/com/cronutils/mapper/CronMapper.java

@@ -25,11 +25,10 @@
 import com.cronutils.model.field.constraint.FieldConstraintsBuilder;
 import com.cronutils.model.field.definition.DayOfWeekFieldDefinition;
 import com.cronutils.model.field.definition.FieldDefinition;
-import com.cronutils.model.field.expression.Always;
-import com.cronutils.model.field.expression.FieldExpression;
-import com.cronutils.model.field.expression.On;
-import com.cronutils.model.field.expression.QuestionMark;
+import com.cronutils.model.field.expression.*;
+import com.cronutils.model.field.expression.visitor.FieldExpressionVisitorAdaptor;
 import com.cronutils.model.field.expression.visitor.ValueMappingFieldExpressionVisitor;
+import com.cronutils.model.field.value.FieldValue;
 import com.cronutils.model.field.value.IntegerFieldValue;
 import com.cronutils.model.field.value.SpecialChar;
 import com.cronutils.utils.Preconditions;
@@ -261,27 +260,45 @@ static Function<CronField, CronField> returnAlwaysExpression(final CronFieldName
         return field -> new CronField(name, always(), FieldConstraintsBuilder.instance().forField(name).createConstraintsInstance());
     }
 
+    private static IntegerFieldValue mapDayOfWeek(DayOfWeekFieldDefinition sourceDef, DayOfWeekFieldDefinition targetDef, IntegerFieldValue fieldValue) {
+        return new IntegerFieldValue(ConstantsMapper.weekDayMapping(sourceDef.getMondayDoWValue(), targetDef.getMondayDoWValue(), fieldValue.getValue()));
+    }
+
+    private static FieldValue<?> mapDayOfWeek(DayOfWeekFieldDefinition sourceDef, DayOfWeekFieldDefinition targetDef, FieldValue<?> fieldValue) {
+        if (fieldValue instanceof IntegerFieldValue) {
+            return mapDayOfWeek(sourceDef, targetDef, (IntegerFieldValue) fieldValue);
+        }
+        return fieldValue;
+    }
+
     @VisibleForTesting
     static Function<CronField, CronField> dayOfWeekMapping(final DayOfWeekFieldDefinition sourceDef, final DayOfWeekFieldDefinition targetDef) {
         return field -> {
             final FieldExpression expression = field.getExpression();
             FieldExpression dest = null;
-            dest = expression.accept(
-                    new ValueMappingFieldExpressionVisitor(
-                            fieldValue -> {
-                                if (fieldValue instanceof IntegerFieldValue) {
-                                    return new IntegerFieldValue(
-                                            ConstantsMapper.weekDayMapping(
-                                                    sourceDef.getMondayDoWValue(),
-                                                    targetDef.getMondayDoWValue(),
-                                                    ((IntegerFieldValue) fieldValue).getValue()
-                                            )
-                                    );
-                                }
-                                return fieldValue;
-                            }
-                    )
-            );
+            dest = expression.accept(new FieldExpressionVisitorAdaptor() {
+                public FieldExpression visit(Every every) {
+                    return new Every(every.getExpression().accept(this), every.getPeriod());
+                }
+
+                public FieldExpression visit(On on) {
+                    return new On(mapDayOfWeek(sourceDef, targetDef, on.getTime()), on.getSpecialChar());
+                }
+
+                @Override
+                public FieldExpression visit(Between between) {
+                    return new Between(mapDayOfWeek(sourceDef, targetDef, between.getFrom()), mapDayOfWeek(sourceDef, targetDef, between.getTo()));
+                }
+
+                @Override
+                public FieldExpression visit(And and) {
+                    And newAnd = new And();
+                    for (FieldExpression expr : and.getExpressions()) {
+                        newAnd.and(expr.accept(this));
+                    }
+                    return newAnd;
+                }
+            });
 
             if (expression instanceof QuestionMark && !targetDef.getConstraints().getSpecialChars().contains(SpecialChar.QUESTION_MARK)) {
                 dest = always();

src/main/java/com/cronutils/parser/FieldParser.java

@@ -120,7 +120,7 @@ private FieldExpression asteriskOrempty(final String start, final String value)
         if (ASTERISK.equals(trimmedStart) || EMPTY_STRING.equals(start.trim())) {
             return new Every(new IntegerFieldValue(Integer.parseInt(value)));
         } else {
-            return new Every(new On(new IntegerFieldValue(Integer.parseInt(start))), new IntegerFieldValue(Integer.parseInt(value)));
+            return new Every(new On(mapToIntegerFieldValue(start)), new IntegerFieldValue(Integer.parseInt(value)));
         }
     }
 

src/test/java/com/cronutils/mapper/CronMapperIntegrationTest.java

@@ -70,8 +70,8 @@ public void testRangeOfTimeQuartzToSpring() {
 
     @Test
     public void testDaysOfWeekUnixToQuartz() {
-        final String input = "* * * * 3,5-6";
-        final String expected = "0 * * ? * 4,6-7 *";
+        final String input = "* * * * 3,5-6,*/2,2/3,7/4";
+        final String expected = "0 * * ? * 4,6-7,*/2,3/3,1/4 *";
         assertEquals(expected, CronMapper.fromUnixToQuartz().map(unixParser().parse(input)).asString());
     }