Add state transition of document test

client/client.go

@@ -53,6 +53,10 @@ var (
 	// this client.
 	ErrDocumentNotAttached = errors.New("document is not attached")
 
+	// ErrDocumentNotDetached occurs when the given document is not detached from
+	// this client.
+	ErrDocumentNotDetached = errors.New("document is not detached")
+
 	// ErrUnsupportedWatchResponseType occurs when the given WatchResponseType
 	// is not supported.
 	ErrUnsupportedWatchResponseType = errors.New("unsupported watch response type")
@@ -246,6 +250,10 @@ func (c *Client) Attach(ctx context.Context, doc *document.Document) error {
 		return ErrClientNotActivated
 	}
 
+	if doc.Status() != document.StatusDetached {
+		return ErrDocumentNotDetached
+	}
+
 	doc.SetActor(c.id)
 
 	pbChangePack, err := converter.ToChangePack(doc.CreateChangePack())

server/backend/database/client_info.go

@@ -38,9 +38,11 @@ const (
 	ClientActivated   = "activated"
 )
 
+// Below are statuses of the document.
 const (
-	documentAttached = "attached"
-	documentDetached = "detached"
+	DocumentAttached = "attached"
+	DocumentDetached = "detached"
+	DocumentRemoved  = "removed"
 )
 
 // ClientDocInfo is a structure representing information of the document
@@ -101,12 +103,12 @@ func (i *ClientInfo) AttachDocument(docID types.ID) error {
 		i.Documents = make(map[types.ID]*ClientDocInfo)
 	}
 
-	if i.hasDocument(docID) && i.Documents[docID].Status == documentAttached {
+	if i.hasDocument(docID) && i.Documents[docID].Status == DocumentAttached {
 		return ErrDocumentAlreadyAttached
 	}
 
 	i.Documents[docID] = &ClientDocInfo{
-		Status:    documentAttached,
+		Status:    DocumentAttached,
 		ServerSeq: 0,
 		ClientSeq: 0,
 	}
@@ -121,7 +123,21 @@ func (i *ClientInfo) DetachDocument(docID types.ID) error {
 		return err
 	}
 
-	i.Documents[docID].Status = documentDetached
+	i.Documents[docID].Status = DocumentDetached
+	i.Documents[docID].ClientSeq = 0
+	i.Documents[docID].ServerSeq = 0
+	i.UpdatedAt = time.Now()
+
+	return nil
+}
+
+// RemoveDocument removes the given document from this client.
+func (i *ClientInfo) RemoveDocument(docID types.ID) error {
+	if err := i.EnsureDocumentAttached(docID); err != nil {
+		return err
+	}
+
+	i.Documents[docID].Status = DocumentRemoved
 	i.Documents[docID].ClientSeq = 0
 	i.Documents[docID].ServerSeq = 0
 	i.UpdatedAt = time.Now()
@@ -135,7 +151,7 @@ func (i *ClientInfo) IsAttached(docID types.ID) (bool, error) {
 		return false, ErrDocumentNeverAttached
 	}
 
-	return i.Documents[docID].Status == documentAttached, nil
+	return i.Documents[docID].Status == DocumentAttached, nil
 }
 
 // Checkpoint returns the checkpoint of the given document.
@@ -170,7 +186,7 @@ func (i *ClientInfo) EnsureDocumentAttached(docID types.ID) error {
 		return ErrClientNotActivated
 	}
 
-	if !i.hasDocument(docID) || i.Documents[docID].Status == documentDetached {
+	if !i.hasDocument(docID) || i.Documents[docID].Status == DocumentDetached {
 		return ErrDocumentNotAttached
 	}
 

server/backend/database/mongo/client_test.go

@@ -138,13 +138,19 @@ func TestClient(t *testing.T) {
 		pack := doc.CreateChangePack()
 
 		// Set removed_at in docInfo and store changes
+		assert.NoError(t, clientInfo.RemoveDocument(docInfo.ID))
 		err = cli.CreateChangeInfos(ctx, dummyProjectID, docInfo, 0, pack.Changes, true)
 		assert.NoError(t, err)
 
 		// Check whether removed_at is set in docInfo
 		docInfo, err = cli.FindDocInfoByID(ctx, dummyProjectID, docInfo.ID)
 		assert.NoError(t, err)
 		assert.NotEqual(t, time.Time{}, docInfo.RemovedAt)
+
+		// Check whether DocumentRemoved status is set in clientInfo
+		clientInfo, err := cli.FindClientInfoByID(ctx, dummyProjectID, clientInfo.ID)
+		assert.NoError(t, err)
+		assert.NotEqual(t, database.DocumentRemoved, clientInfo.Documents[docInfo.ID].Status)
 	})
 
 	t.Run("reuse same key to create docInfo test ", func(t *testing.T) {

server/rpc/yorkie_server.go

@@ -525,7 +525,7 @@ func (s *yorkieServer) RemoveDocument(
 		return nil, err
 	}
 
-	if err := clientInfo.DetachDocument(docInfo.ID); err != nil {
+	if err := clientInfo.RemoveDocument(docInfo.ID); err != nil {
 		return nil, err
 	}
 

test/integration/document_test.go

@@ -326,4 +326,37 @@ func TestDocument(t *testing.T) {
 		assert.Equal(t, d1.Status(), document.StatusRemoved)
 		assert.Equal(t, d2.Status(), document.StatusRemoved)
 	})
+
+	// State transition of document
+	// ┌──────────┐ Attach ┌──────────┐ Remove ┌─────────┐
+	// │ Detached ├───────►│ Attached ├───────►│ Removed │
+	// └──────────┘        └─┬─┬──────┘        └─────────┘
+	//	         ▲           │ │     ▲
+	//	         └───────────┘ └─────┘
+	//	             Detach     PushPull
+	t.Run("document state transition test", func(t *testing.T) {
+		ctx := context.Background()
+		cli, err := client.Dial(defaultServer.RPCAddr())
+		assert.NoError(t, err)
+		assert.NoError(t, cli.Activate(ctx))
+		defer func() {
+			assert.NoError(t, cli.Close())
+		}()
+
+		// 01. abnormal behavior on detached state
+		d1 := document.New(key.Key(helper.TestDocKey(t)))
+		assert.ErrorIs(t, cli.Detach(ctx, d1), client.ErrDocumentNotAttached)
+		assert.ErrorIs(t, cli.Sync(ctx, d1.Key()), client.ErrDocumentNotAttached)
+		assert.ErrorIs(t, cli.Remove(ctx, d1), client.ErrDocumentNotAttached)
+
+		// 02. abnormal behavior on attached state
+		assert.NoError(t, cli.Attach(ctx, d1))
+		assert.ErrorIs(t, cli.Attach(ctx, d1), client.ErrDocumentNotDetached)
+
+		// 03. abnormal behavior on removed state
+		assert.NoError(t, cli.Remove(ctx, d1))
+		assert.ErrorIs(t, cli.Remove(ctx, d1), client.ErrDocumentNotAttached)
+		assert.ErrorIs(t, cli.Sync(ctx, d1.Key()), client.ErrDocumentNotAttached)
+		assert.ErrorIs(t, cli.Detach(ctx, d1), client.ErrDocumentNotAttached)
+	})
 }