fix: add mutex to fix race conditions for consumers

mocks.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2020 Unbound Software Development Svenska AB
+// Copyright (c) 2022 Unbound Software Development Svenska AB
 //
 // Permission is hereby granted, free of charge, to any person obtaining a copy of
 // this software and associated documentation files (the "Software"), to deal in
@@ -21,19 +21,24 @@ package apex
 
 import (
 	"fmt"
-	"github.com/apex/log"
-	"github.com/sanity-io/litter"
+	"sync"
 	"testing"
+
+	"github.com/apex/log"
+	"github.com/stretchr/testify/assert"
 )
 
 // Mock has a Logger for use in unit-testing
 type Mock struct {
+	*sync.RWMutex
 	Logger log.Interface
 	Logged []string
 }
 
 // HandleLog stores the logged entries to be able to check them later
 func (m *Mock) HandleLog(entry *log.Entry) error {
+	m.Lock()
+	defer m.Unlock()
 	m.Logged = append(m.Logged, fmt.Sprintf("%s: %s", entry.Level.String(), entry.Message))
 	return nil
 }
@@ -43,7 +48,8 @@ var _ log.Handler = &Mock{}
 // New instantiates a new Mock and sets the log.Handler to it
 func New() *Mock {
 	mock := &Mock{
-		Logger: log.Log,
+		RWMutex: &sync.RWMutex{},
+		Logger:  log.Log,
 	}
 	log.SetHandler(mock)
 	return mock
@@ -52,11 +58,7 @@ func New() *Mock {
 // Check verifies that the application has logged the expected strings
 func (m *Mock) Check(t testing.TB, wantLogged []string) {
 	t.Helper()
-	if len(m.Logged) != 0 || len(wantLogged) != 0 {
-		got := litter.Sdump(m.Logged)
-		want := litter.Sdump(wantLogged)
-		if got != want {
-			t.Errorf("Logger() got %s, want %s", got, want)
-		}
-	}
+	m.RLock()
+	defer m.RUnlock()
+	assert.Equal(t, wantLogged, m.Logged)
 }