Add basic tests for providers

alerting/provider/pagerduty/pagerduty_test.go

@@ -1,6 +1,9 @@
 package pagerduty
 
-import "testing"
+import (
+	"github.com/TwinProduction/gatus/core"
+	"testing"
+)
 
 func TestAlertProvider_IsValid(t *testing.T) {
 	invalidProvider := AlertProvider{IntegrationKey: ""}
@@ -12,3 +15,11 @@ func TestAlertProvider_IsValid(t *testing.T) {
 		t.Error("provider should've been valid")
 	}
 }
+
+func TestAlertProvider_ToCustomAlertProvider(t *testing.T) {
+	provider := AlertProvider{IntegrationKey: "00000000000000000000000000000000"}
+	customAlertProvider := provider.ToCustomAlertProvider(&core.Service{}, &core.Alert{}, &core.Result{}, true)
+	if customAlertProvider == nil {
+		t.Error("customAlertProvider shouldn't have been nil")
+	}
+}