fix(storage): resolve race condition in memory store (#1270)

* fix(storage): resolve race condition in memory store

* fix: resolve variable shadowing in CopyEndpointStatus

* fix: update test files to use CopyEndpointStatus function

storage/store/memory/util.go

@@ -6,35 +6,47 @@ import (
 	"github.com/TwiN/gatus/v5/storage/store/common/paging"
 )
 
-// ShallowCopyEndpointStatus returns a shallow copy of a Status with only the results
-// within the range defined by the page and pageSize parameters
-func ShallowCopyEndpointStatus(ss *endpoint.Status, params *paging.EndpointStatusParams) *endpoint.Status {
-	shallowCopy := &endpoint.Status{
+// CopyEndpointStatus returns a safe copy of a Status with only the results
+// within the range defined by the page and pageSize parameters.
+// This function performs deep copying of slices to prevent race conditions
+// when the original slice is modified concurrently.
+func CopyEndpointStatus(ss *endpoint.Status, params *paging.EndpointStatusParams) *endpoint.Status {
+	statusCopy := &endpoint.Status{
 		Name:   ss.Name,
 		Group:  ss.Group,
 		Key:    ss.Key,
 		Uptime: endpoint.NewUptime(),
 	}
 	if params == nil || (params.ResultsPage == 0 && params.ResultsPageSize == 0 && params.EventsPage == 0 && params.EventsPageSize == 0) {
-		shallowCopy.Results = ss.Results
-		shallowCopy.Events = ss.Events
+		// Deep copy all results to prevent race conditions
+		statusCopy.Results = make([]*endpoint.Result, len(ss.Results))
+		copy(statusCopy.Results, ss.Results)
+		// Deep copy all events to prevent race conditions
+		statusCopy.Events = make([]*endpoint.Event, len(ss.Events))
+		copy(statusCopy.Events, ss.Events)
 	} else {
 		numberOfResults := len(ss.Results)
 		resultsStart, resultsEnd := getStartAndEndIndex(numberOfResults, params.ResultsPage, params.ResultsPageSize)
 		if resultsStart < 0 || resultsEnd < 0 {
-			shallowCopy.Results = []*endpoint.Result{}
+			statusCopy.Results = []*endpoint.Result{}
 		} else {
-			shallowCopy.Results = ss.Results[resultsStart:resultsEnd]
+			// Deep copy the slice range to prevent race conditions
+			resultRange := ss.Results[resultsStart:resultsEnd]
+			statusCopy.Results = make([]*endpoint.Result, len(resultRange))
+			copy(statusCopy.Results, resultRange)
 		}
 		numberOfEvents := len(ss.Events)
 		eventsStart, eventsEnd := getStartAndEndIndex(numberOfEvents, params.EventsPage, params.EventsPageSize)
 		if eventsStart < 0 || eventsEnd < 0 {
-			shallowCopy.Events = []*endpoint.Event{}
+			statusCopy.Events = []*endpoint.Event{}
 		} else {
-			shallowCopy.Events = ss.Events[eventsStart:eventsEnd]
+			// Deep copy the slice range to prevent race conditions
+			eventRange := ss.Events[eventsStart:eventsEnd]
+			statusCopy.Events = make([]*endpoint.Event, len(eventRange))
+			copy(statusCopy.Events, eventRange)
 		}
 	}
-	return shallowCopy
+	return statusCopy
 }
 
 // ShallowCopySuiteStatus returns a shallow copy of a suite Status with only the results