Merge pull request #14 from adel-hadadi/add-support-for-repository-rules

added: exists rule

exists.go

@@ -0,0 +1,15 @@
+package validator
+
+const (
+	// Exists represents the rule name which will be used to find the default error message.
+	Exists = "exists"
+	// ExistsMsg is default error message format for records that not exists.
+	ExistsMsg = "% not exists"
+)
+
+// Exists checks if given value is exists in database.
+func (v *Validator) Exists(value any, table, column, field, msg string) *Validator {
+	v.Check(v.repo.Exists(value, table, column), field, msg)
+
+	return v
+}

exists_test.go

@@ -0,0 +1,90 @@
+package validator
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+var (
+	tables = map[string][]map[string]any{
+		"users": {
+			{
+				"id":       1,
+				"username": "test_1",
+			},
+			{
+				"id":       2,
+				"username": "test_2",
+			},
+		},
+	}
+)
+
+type repo struct{}
+
+func (repo) Exists(value any, table, column string) bool {
+	data, exists := tables[table]
+	if !exists {
+		return false
+	}
+
+	for _, item := range data {
+		if item[column] == value {
+			return true
+		}
+	}
+
+	return false
+}
+
+func TestValidator_Exists(t *testing.T) {
+	tests := []struct {
+		tag         string
+		value       any
+		table       string
+		column      string
+		isPassed    bool
+		msg         string
+		expectedMsg string
+	}{
+		{
+			tag:         "id",
+			value:       5,
+			table:       "users",
+			column:      "id",
+			isPassed:    false,
+			msg:         "record not exists",
+			expectedMsg: "record not exists",
+		},
+		{
+			tag:         "username",
+			value:       "test_1",
+			table:       "users",
+			column:      "username",
+			isPassed:    true,
+			msg:         "",
+			expectedMsg: "",
+		},
+		{
+			tag:         "username_2",
+			value:       "test_5",
+			table:       "users",
+			column:      "username",
+			isPassed:    false,
+			msg:         "",
+			expectedMsg: "username_2 not exists",
+		},
+	}
+
+	v := New().WithRepo(repo{})
+
+	for _, test := range tests {
+		v.Exists(test.value, test.table, test.column, test.tag, test.msg)
+
+		assert.Equal(t, test.isPassed, v.IsPassed())
+
+		if v.IsFailed() {
+			assert.Equal(t, test.msg, v.Errors()[test.tag])
+		}
+	}
+}

validator.go

@@ -11,7 +11,13 @@ type (
 	// Err is the defined type which will be returned when one or many validator rules fail.
 	Err = map[string]string
 	// Validator represents the validator structure
-	Validator struct{}
+	Validator struct {
+		repo Repository
+	}
+	// Repository represent needed repository methods for using in some rules that need database connection.
+	Repository interface {
+		Exists(value any, table, column string) bool
+	}
 )
 
 var (
@@ -21,6 +27,7 @@ var (
 	// methodToErrorMessage contains each validation method and its corresponding error message.
 	methodToErrorMessage = map[string]string{
 		Required: RequiredMsg,
+		Exists:   ExistsMsg,
 		Len:      LenMsg,
 		Max:      MaxMsg,
 		Min:      MinMsg,
@@ -36,6 +43,13 @@ func New() *Validator {
 	return &Validator{}
 }
 
+// WithRepo get a repository for using validation rules that need to contact with database
+func (v *Validator) WithRepo(r Repository) *Validator {
+	v.repo = r
+
+	return v
+}
+
 // IsPassed checks validator result is passed or not.
 func (v *Validator) IsPassed() bool {
 	return len(errs) == 0