Wrote tests for 100% coverage

Update RetryAmbiguousDateWithSwap detection logic after testing

parseany.go

@@ -217,14 +217,20 @@ func parseTime(datestr string, loc *time.Location, opts ...ParserOption) (p *par
 		// this is because it means that a day is being interpreted as a month and overflowing the valid value for that
 		// by retrying in this case, we can fix a common situation with no assumptions
 		defer func() {
-			if err != nil && strings.Contains(err.Error(), "month out of range") {
+			if p.ambiguousMD {
-				// create the option to reverse the preference
+				// if it errors out with the following error, swap before we
-				preferMonthFirst := PreferMonthFirst(!p.preferMonthFirst)
+				// get out of this function to reduce scope it needs to be applied on
-				// turn off the retry to avoid endless recursion
+				_, err := p.parse()
-				retryAmbiguousDateWithSwap := RetryAmbiguousDateWithSwap(false)
+				if err != nil && strings.Contains(err.Error(), "month out of range") {
-				modifiedOpts := append(opts, preferMonthFirst, retryAmbiguousDateWithSwap)
+					// create the option to reverse the preference
-				p, err = parseTime(datestr, time.Local, modifiedOpts...)
+					preferMonthFirst := PreferMonthFirst(!p.preferMonthFirst)
+					// turn off the retry to avoid endless recursion
+					retryAmbiguousDateWithSwap := RetryAmbiguousDateWithSwap(false)
+					modifiedOpts := append(opts, preferMonthFirst, retryAmbiguousDateWithSwap)
+					p, err = parseTime(datestr, time.Local, modifiedOpts...)
+				}
 			}
+
 		}()
 	}
 

parseany_test.go

@@ -669,3 +669,38 @@ func TestInLocation(t *testing.T) {
 	assert.Equal(t, zeroTime, ts.Unix())
 	assert.NotEqual(t, nil, err)
 }
+
+func TestPreferMonthFirst(t *testing.T) {
+	// default case is true
+	ts, err := ParseAny("04/02/2014 04:08:09 +0000 UTC")
+	assert.Equal(t, nil, err)
+	assert.Equal(t, "2014-04-02 04:08:09 +0000 UTC", fmt.Sprintf("%v", ts.In(time.UTC)))
+
+	preferMonthFirstTrue := PreferMonthFirst(true)
+	ts, err = ParseAny("04/02/2014 04:08:09 +0000 UTC", preferMonthFirstTrue)
+	assert.Equal(t, nil, err)
+	assert.Equal(t, "2014-04-02 04:08:09 +0000 UTC", fmt.Sprintf("%v", ts.In(time.UTC)))
+
+	// allows the day to be preferred before the month, when completely ambiguous
+	preferMonthFirstFalse := PreferMonthFirst(false)
+	ts, err = ParseAny("04/02/2014 04:08:09 +0000 UTC", preferMonthFirstFalse)
+	assert.Equal(t, nil, err)
+	assert.Equal(t, "2014-02-04 04:08:09 +0000 UTC", fmt.Sprintf("%v", ts.In(time.UTC)))
+}
+
+func TestRetryAmbiguousDateWithSwap(t *testing.T) {
+	// default is false
+	_, err := ParseAny("13/02/2014 04:08:09 +0000 UTC")
+	assert.NotEqual(t, nil, err)
+
+	// will fail error if the month preference cannot work due to the value being larger than 12
+	retryAmbiguousDateWithSwapFalse := RetryAmbiguousDateWithSwap(false)
+	_, err = ParseAny("13/02/2014 04:08:09 +0000 UTC", retryAmbiguousDateWithSwapFalse)
+	assert.NotEqual(t, nil, err)
+
+	// will retry with the other month preference if this error is detected
+	retryAmbiguousDateWithSwapTrue := RetryAmbiguousDateWithSwap(true)
+	ts, err := ParseAny("13/02/2014 04:08:09 +0000 UTC", retryAmbiguousDateWithSwapTrue)
+	assert.Equal(t, nil, err)
+	assert.Equal(t, "2014-02-13 04:08:09 +0000 UTC", fmt.Sprintf("%v", ts.In(time.UTC)))
+}