datastore: Concurrency fix, closes #77

datastore/testing.go

@@ -3,6 +3,7 @@ package datastore
 import (
 	"io"
 	"net/mail"
+	"sync"
 	"time"
 
 	"github.com/jhillyerd/enmime"
@@ -26,6 +27,10 @@ func (m *MockDataStore) AllMailboxes() ([]Mailbox, error) {
 	return args.Get(0).([]Mailbox), args.Error(1)
 }
 
+func (m *MockDataStore) LockFor(name string) (*sync.RWMutex, error) {
+	return &sync.RWMutex{}, nil
+}
+
 // MockMailbox is a shared mock for unit testing
 type MockMailbox struct {
 	mock.Mock