feat: add option for custom validator

options.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/getkin/kin-openapi/openapi3"
+	"github.com/go-playground/validator/v10"
 	"github.com/golang-jwt/jwt/v5"
 )
 
@@ -261,3 +262,25 @@ func WithOpenapiConfig(openapiConfig OpenapiConfig) func(*Server) {
 		}
 	}
 }
+
+// WithValidator sets the validator to be used by the fuego server.
+// If no validator is provided, a default validator will be used.
+//
+// Note: If you are using the default validator, you can add tags to your structs using the `validate` tag.
+// For example:
+//
+//	type MyStruct struct {
+//		Field1 string `validate:"required"`
+//		Field2 int    `validate:"min=10,max=20"`
+//	}
+//
+// The above struct will be validated using the default validator, and if any errors occur, they will be returned as part of the response.
+func WithValidator(newValidator *validator.Validate) func(*Server) {
+	if newValidator == nil {
+		panic("new validator not provided")
+	}
+
+	return func(s *Server) {
+		v = newValidator
+	}
+}

options_test.go

@@ -8,6 +8,8 @@ import (
 	"net/http/httptest"
 	"testing"
 
+	"github.com/go-playground/validator/v10"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
@@ -179,3 +181,44 @@ func TestWithLogHandler(t *testing.T) {
 		WithLogHandler(handler),
 	)
 }
+
+func TestWithValidator(t *testing.T) {
+	type args struct {
+		newValidator *validator.Validate
+	}
+	tests := []struct {
+		name      string
+		args      args
+		wantPanic bool
+	}{
+		{
+			name: "with custom validator",
+			args: args{
+				newValidator: validator.New(),
+			},
+		},
+		{
+			name: "no validator provided",
+			args: args{
+				newValidator: nil,
+			},
+			wantPanic: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(
+			tt.name, func(t *testing.T) {
+				if tt.wantPanic {
+					assert.Panics(
+						t, func() { WithValidator(tt.args.newValidator) },
+					)
+				} else {
+					NewServer(
+						WithValidator(tt.args.newValidator),
+					)
+					assert.Equal(t, tt.args.newValidator, v)
+				}
+			},
+		)
+	}
+}