Fix log, and first simple test

internal/parser/parser.go

@@ -54,7 +54,7 @@ func (s *Scanner) Start() {
 					}
 				} else {
 					if err := s.scanner.Err(); err != nil {
-						s.logger.Error("Scanner error:", err)
+						s.logger.Error("Scanner error")
 						return
 					}
 					time.Sleep(s.pollDelay)

internal/parser/parser_test.go

@@ -0,0 +1,22 @@
+package parser
+
+import (
+	"os"
+	"testing"
+)
+
+func TestNewScanner(t *testing.T) {
+	file, err := os.CreateTemp("", "test.log")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer file.Close()
+	defer os.Remove(file.Name())
+	s, err := NewScanner(file.Name())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if s == nil {
+		t.Fatal("Scanner is nil")
+	}
+}