fix: skip posts with empty date

internal/dateparser/dateparser.go

@@ -1,6 +1,7 @@
 package dateparser
 
 import (
+	"fmt"
 	godateparser "github.com/markusmobius/go-dateparser"
 	"strings"
 	"time"
@@ -13,6 +14,10 @@ type DateParser struct {
 func (d *DateParser) ParseDate(str string) (time.Time, error) {
 	str = strings.TrimSpace(str)
 
+	if len(str) == 0 {
+		return time.Time{}, fmt.Errorf("date string is empty")
+	}
+
 	dt, err := godateparser.Parse(&godateparser.Configuration{
 		CurrentTime: d.CurrentTimeFunc(),
 	}, str)

internal/extractors/pwextractor/pwextractor.go

@@ -287,7 +287,7 @@ func (p *pageParser) parse() (*models.TaskResult, error) {
 			log.Errorf("extract post fields: %v", err)
 			continue
 		}
-		if len(item.Title) == 0 || len(item.Link) == 0 {
+		if len(item.Title) == 0 || len(item.Link) == 0 || item.Created.IsZero() {
 			log.Warnf("post has no required fields, skip")
 			continue
 		}