Improves the initialization (#124)

* Improves the initialization

* Update jupyter_ydoc/ydoc.py

* Review

* Fixes tests

* Fix nbformat

* Fix tests

* Improve tests

* Lint

Co-authored-by: David Brochart <david.brochart@gmail.com>

Author: hbcarlos

javascript/src/api.ts

@@ -345,6 +345,11 @@ export namespace ISharedNotebook {
      * considered on the full document across all cells.
      */
     disableDocumentWideUndoRedo?: boolean;
+
+    /**
+     * The language preference for the model.
+     */
+    languagePreference?: string;
   }
 }
 

javascript/src/ynotebook.ts

@@ -75,7 +75,14 @@ export class YNotebook
     const ynotebook = new YNotebook({
       disableDocumentWideUndoRedo: options.disableDocumentWideUndoRedo ?? false
     });
-    ynotebook.ymeta.set('metadata', new Y.Map());
+    const ymetadata = new Y.Map();
+    ymetadata.set('language_info', { name: options.languagePreference ?? '' });
+    ymetadata.set('kernelspec', {
+      name: '',
+      display_name: ''
+    });
+    ynotebook.ymeta.set('metadata', ymetadata);
+
     return ynotebook;
   }
 
@@ -404,7 +411,16 @@ export class YNotebook
       if (metadata['orig_nbformat'] !== undefined) {
         delete metadata['orig_nbformat'];
       }
-      this.metadata = metadata;
+
+      if (!this.metadata) {
+        const ymetadata = new Y.Map();
+        for (const [key, value] of Object.entries(metadata)) {
+          ymetadata.set(key, value);
+        }
+        this.ymeta.set('metadata', ymetadata);
+      } else {
+        this.metadata = metadata;
+      }
 
       const useId = value.nbformat === 4 && value.nbformat_minor >= 5;
       const ycells = value.cells.map(cell => {
@@ -449,7 +465,6 @@ export class YNotebook
 
     if (metadataEvents) {
       const metadataChange = metadataEvents.changes.keys;
-
       const ymetadata = this.ymeta.get('metadata') as Y.Map<any>;
       metadataEvents.changes.keys.forEach((change, key) => {
         switch (change.action) {

javascript/test/ymodels.spec.ts

@@ -139,6 +139,7 @@ describe('@jupyter/ydoc', () => {
 
       test('should emit all metadata changes', () => {
         const notebook = YNotebook.create();
+
         const metadata = {
           orig_nbformat: 1,
           kernelspec: {
@@ -153,19 +154,58 @@ describe('@jupyter/ydoc', () => {
         });
         notebook.metadata = metadata;
 
+        expect(changes).toHaveLength(3);
+        expect(changes).toEqual([
+          {
+            type: 'remove',
+            key: 'language_info',
+            oldValue: { name: '' }
+          },
+          {
+            type: 'change',
+            key: 'kernelspec',
+            newValue: metadata.kernelspec,
+            oldValue: { display_name: '', name: '' }
+          },
+          {
+            type: 'add',
+            key: 'orig_nbformat',
+            newValue: metadata.orig_nbformat
+          }
+        ]);
+
+        notebook.dispose();
+      });
+
+      test('should emit all metadata changes on update', () => {
+        const notebook = YNotebook.create();
+
+        const metadata = {
+          orig_nbformat: 1,
+          kernelspec: {
+            display_name: 'python',
+            name: 'python'
+          }
+        };
+
+        const changes: IMapChange[] = [];
+        notebook.metadataChanged.connect((_, c) => {
+          changes.push(c);
+        });
+        notebook.updateMetadata(metadata);
+
         expect(changes).toHaveLength(2);
         expect(changes).toEqual([
           {
             type: 'add',
             key: 'orig_nbformat',
-            newValue: metadata.orig_nbformat,
-            oldValue: undefined
+            newValue: metadata.orig_nbformat
           },
           {
-            type: 'add',
+            type: 'change',
             key: 'kernelspec',
             newValue: metadata.kernelspec,
-            oldValue: undefined
+            oldValue: { display_name: '', name: '' }
           }
         ]);
 
@@ -502,6 +542,7 @@ describe('@jupyter/ydoc', () => {
 
     test('should emit all metadata changes', () => {
       const notebook = YNotebook.create();
+
       const metadata = {
         collapsed: true,
         editable: false,
@@ -514,8 +555,20 @@ describe('@jupyter/ydoc', () => {
       });
       notebook.metadata = metadata;
 
-      expect(changes).toHaveLength(3);
+      expect(changes).toHaveLength(5);
       expect(changes).toEqual([
+        {
+          type: 'remove',
+          key: 'language_info',
+          newValue: undefined,
+          oldValue: { name: '' }
+        },
+        {
+          type: 'remove',
+          key: 'kernelspec',
+          newValue: undefined,
+          oldValue: { display_name: '', name: '' }
+        },
         {
           type: 'add',
           key: 'collapsed',

jupyter_ydoc/ydoc.py

@@ -10,6 +10,11 @@
 
 from .utils import cast_all
 
+# The default major version of the notebook format.
+NBFORMAT_MAJOR_VERSION = 4
+# The default minor version of the notebook format.
+NBFORMAT_MINOR_VERSION = 5
+
 
 class YBaseDoc(ABC):
     """
@@ -424,9 +429,14 @@ def set(self, value: Dict) -> None:
 
             # initialize document
             self._ycells.extend(t, [self.create_ycell(cell) for cell in cells])
-            self._ymeta.set(t, "nbformat", nb["nbformat"])
-            self._ymeta.set(t, "nbformat_minor", nb["nbformat_minor"])
-            self._ymeta.set(t, "metadata", Y.YMap(nb.get("metadata", {})))
+            self._ymeta.set(t, "nbformat", nb.get("nbformat", NBFORMAT_MAJOR_VERSION))
+            self._ymeta.set(t, "nbformat_minor", nb.get("nbformat_minor", NBFORMAT_MINOR_VERSION))
+
+            metadata = nb.get("metadata", {})
+            metadata.setdefault("language_info", {"name": ""})
+            metadata.setdefault("kernelspec", {"name": "", "display_name": ""})
+
+            self._ymeta.set(t, "metadata", Y.YMap(metadata))
 
     def observe(self, callback: Callable[[Any], None]) -> None:
         """