feat: add custom tag/expr

Signed-off-by: rfyiamcool <[email protected]>

gronx.go

@@ -2,6 +2,7 @@ package gronx
 
 import (
 	"errors"
+	"fmt"
 	"regexp"
 	"strings"
 	"time"
@@ -29,6 +30,23 @@ var expressions = map[string]string{
 	"@everysecond": "* * * * * *",
 }
 
+func AddTag(tag, expr string) error {
+	_, ok := expressions[tag]
+	if ok {
+		return errors.New("conflict tag")
+	}
+
+	segs, err := Segments(expr)
+	if err != nil {
+		return err
+	}
+	expr = strings.Join(segs, " ")
+
+	expressions[tag] = expr
+	fmt.Println(expr)
+	return nil
+}
+
 // SpaceRe is regex for whitespace.
 var SpaceRe = regexp.MustCompile(`\s+`)
 var yearRe = regexp.MustCompile(`\d{4}`)

gronx_test.go

@@ -93,6 +93,29 @@ func TestIsValid(t *testing.T) {
 
 }
 
+func TestAddTag(t *testing.T) {
+	t.Run("add good tag", func(t *testing.T) {
+		err := AddTag("@2s", "*/2 * * * * *")
+		if err != nil {
+			t.Error("expected nil, got err")
+		}
+	})
+
+	t.Run("add conflict tag", func(t *testing.T) {
+		err := AddTag("@2s", "*/2 * * * * *")
+		if err == nil {
+			t.Error("expected err, got nil")
+		}
+	})
+
+	t.Run("add wrong tag", func(t *testing.T) {
+		err := AddTag("@3s", "* * * *")
+		if err == nil {
+			t.Error("expected err, got nil")
+		}
+	})
+}
+
 func TestIsDue(t *testing.T) {
 	gron := New()