refactor: Break core package into multiple packages under config/endpoint (#759)

* refactor: Partially break core package into dns, result and ssh packages

* refactor: Move core package to config/endpoint

* refactor: Fix warning about overlapping imported package name with endpoint variable

* refactor: Rename EndpointStatus to Status

* refactor: Merge result pkg back into endpoint pkg, because it makes more sense

* refactor: Rename parameter r to result in Condition.evaluate

* refactor: Rename parameter r to result

* refactor: Revert accidental change to endpoint.TypeDNS

* refactor: Rename parameter r to result

* refactor: Merge util package into endpoint package

* refactor: Rename parameter r to result

config/endpoint/common.go

@@ -0,0 +1,32 @@
+package endpoint
+
+import (
+	"errors"
+	"strings"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+)
+
+var (
+	// ErrEndpointWithNoName is the error with which Gatus will panic if an endpoint is configured with no name
+	ErrEndpointWithNoName = errors.New("you must specify a name for each endpoint")
+
+	// ErrEndpointWithInvalidNameOrGroup is the error with which Gatus will panic if an endpoint has an invalid character where it shouldn't
+	ErrEndpointWithInvalidNameOrGroup = errors.New("endpoint name and group must not have \" or \\")
+)
+
+// validateEndpointNameGroupAndAlerts validates the name, group and alerts of an endpoint
+func validateEndpointNameGroupAndAlerts(name, group string, alerts []*alert.Alert) error {
+	if len(name) == 0 {
+		return ErrEndpointWithNoName
+	}
+	if strings.ContainsAny(name, "\"\\") || strings.ContainsAny(group, "\"\\") {
+		return ErrEndpointWithInvalidNameOrGroup
+	}
+	for _, endpointAlert := range alerts {
+		if err := endpointAlert.ValidateAndSetDefaults(); err != nil {
+			return err
+		}
+	}
+	return nil
+}