Merge pull request #10 from DRK3/PreventDuplicateStore

refactor: Prevent creation of duplicate store and return custom error

pkg/storage/couchdb/couchdbstore.go

@@ -50,10 +50,15 @@ func NewProvider(hostURL string) (*Provider, error) {
 // CreateStore creates a new store with the given name.
 func (p *Provider) CreateStore(name string) error {
 	p.mux.Lock()
-	defer p.mux.Unlock()
 
 	err := p.couchDBClient.CreateDB(context.Background(), name)
 
+	p.mux.Unlock()
+
+	if err != nil && err.Error() == "Precondition Failed: The database could not be created, the file already exists." {
+		return storage.ErrDuplicateStore
+	}
+
 	return err
 }
 

pkg/storage/couchdb/couchdbstore_test.go

@@ -97,8 +97,7 @@ func TestProvider_CreateStore(t *testing.T) {
 		require.NoError(t, err)
 
 		err = provider.CreateStore(testStoreName)
-		require.Equal(t, "Precondition Failed: The database could not be created, the file already exists.",
-			err.Error())
+		require.Equal(t, storage.ErrDuplicateStore.Error(), err.Error())
 	})
 	t.Run("Attempt to create a store with an incompatible name", func(t *testing.T) {
 		provider := initializeTest(t)

pkg/storage/memstore/memstore.go

@@ -28,6 +28,11 @@ func (p *Provider) CreateStore(name string) error {
 	p.mux.Lock()
 	defer p.mux.Unlock()
 
+	_, exists := p.dbs[name]
+	if exists {
+		return storage.ErrDuplicateStore
+	}
+
 	store := MemStore{db: make(map[string][]byte)}
 
 	p.dbs[name] = &store

pkg/storage/memstore/memstore_test.go

@@ -17,10 +17,21 @@ import (
 const testStoreName = "teststore"
 
 func TestProvider_CreateStore(t *testing.T) {
-	provider := NewProvider()
+	t.Run("Successfully create a new store", func(t *testing.T) {
+		provider := NewProvider()
 
-	err := provider.CreateStore(testStoreName)
-	require.NoError(t, err)
+		err := provider.CreateStore(testStoreName)
+		require.NoError(t, err)
+	})
+	t.Run("Attempt to create a duplicate store", func(t *testing.T) {
+		provider := NewProvider()
+
+		err := provider.CreateStore(testStoreName)
+		require.NoError(t, err)
+
+		err = provider.CreateStore(testStoreName)
+		require.Equal(t, storage.ErrDuplicateStore, err)
+	})
 }
 
 func TestMemStore_OpenStore(t *testing.T) {

pkg/storage/store.go

@@ -8,10 +8,13 @@ package storage
 
 import "errors"
 
+// ErrDuplicateStore is used when an attempt is made to create a duplicate store.
+var ErrDuplicateStore = errors.New("store already exists")
+
 // ErrStoreNotFound is used when a given store was not found in a provider.
 var ErrStoreNotFound = errors.New("store not found")
 
-// ErrValueNotFound is used when an attempt is made to retrieve a value from key
+// ErrValueNotFound is used when an attempt is made to retrieve a value using a key that isn't in the store.
 var ErrValueNotFound = errors.New("store does not have a value associated with this key")
 
 // Provider represents a storage provider.