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_test.go

@@ -0,0 +1,51 @@
+package endpoint
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+)
+
+func TestValidateEndpointNameGroupAndAlerts(t *testing.T) {
+	scenarios := []struct {
+		name        string
+		group       string
+		alerts      []*alert.Alert
+		expectedErr error
+	}{
+		{
+			name:   "n",
+			group:  "g",
+			alerts: []*alert.Alert{{Type: "slack"}},
+		},
+		{
+			name:   "n",
+			alerts: []*alert.Alert{{Type: "slack"}},
+		},
+		{
+			group:       "g",
+			alerts:      []*alert.Alert{{Type: "slack"}},
+			expectedErr: ErrEndpointWithNoName,
+		},
+		{
+			name:        "\"",
+			alerts:      []*alert.Alert{{Type: "slack"}},
+			expectedErr: ErrEndpointWithInvalidNameOrGroup,
+		},
+		{
+			name:        "n",
+			group:       "\\",
+			alerts:      []*alert.Alert{{Type: "slack"}},
+			expectedErr: ErrEndpointWithInvalidNameOrGroup,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			err := validateEndpointNameGroupAndAlerts(scenario.name, scenario.group, scenario.alerts)
+			if !errors.Is(err, scenario.expectedErr) {
+				t.Errorf("expected error to be %v but got %v", scenario.expectedErr, err)
+			}
+		})
+	}
+}