Allow diffing with @codemirror/merge

.prettierignore

@@ -4,3 +4,4 @@ node_modules
 **/package.json
 !/package.json
 jupyterlab_cell_diff
+.venv

README.md

@@ -1,25 +1,66 @@
-# JupyterLab Plugin: Show a Cell Diff
+# jupyterlab-cell-diff
 
 [![Github Actions Status](https://github.com/jupyter-ai-contrib/jupyterlab-cell-diff/workflows/Build/badge.svg)](https://github.com/jupyter-ai-contrib/jupyterlab-cell-diff/actions/workflows/build.yml)
 
-A JupyterLab Extension for showing cell (git) diffs.
-
-This extension is composed of a Python package named `jupyterlab_cell_diff`
-for the server extension and a NPM package named `jupyterlab-cell-diff`
-for the frontend extension.
+A JupyterLab extension for showing cell diffs with multiple diffing strategies.
 
 ## Requirements
 
 - JupyterLab >= 4.0.0
 
-## Install
+## Installation
 
-To install the extension, execute:
+### PyPI Installation
 
 ```bash
 pip install jupyterlab_cell_diff
 ```
 
+### Development Installation
+
+```bash
+# Clone the repository
+git clone https://github.com/jupyter-ai-contrib/jupyterlab-cell-diff.git
+cd jupyterlab-cell-diff
+
+# Install the extension in development mode
+pip install -e .
+jupyter labextension develop . --overwrite
+```
+
+## Usage
+
+### Commands
+
+The extension provides several commands:
+
+- `jupyterlab-cell-diff:show-codemirror` - Show diff using `@codemirror/merge`
+- `jupyterlab-cell-diff:show-nbdime` - Show diff using NBDime
+
+### Use with `@codemirror/merge`
+
+https://github.com/user-attachments/assets/0dacd7f0-5963-4ebe-81da-2958f0117071
+
+### Use with NBDime
+
+https://github.com/user-attachments/assets/87e93eab-ad67-468c-b228-f5a0e93f8bea
+
+### Programmatic Usage
+
+```typescript
+app.commands.execute('jupyterlab-cell-diff:show-codemirror', {
+  cellId: 'cell-id',
+  originalSource: 'print("Hello")',
+  newSource: 'print("Hello, World!")'
+});
+
+app.commands.execute('jupyterlab-cell-diff:show-nbdime', {
+  cellId: 'cell-id',
+  originalSource: 'print("Hello")',
+  newSource: 'print("Hello, World!")'
+});
+```
+
 ## Uninstall
 
 To remove the extension, execute:

package.json

@@ -19,7 +19,8 @@
     "files": [
         "lib/**/*.{d.ts,eot,gif,html,jpg,js,js.map,json,png,svg,woff2,ttf}",
         "style/**/*.{css,js,eot,gif,html,jpg,json,png,svg,woff2,ttf}",
-        "src/**/*.{ts,tsx}"
+        "src/**/*.{ts,tsx}",
+        "schema/*.json"
     ],
     "main": "lib/index.js",
     "types": "lib/index.d.ts",
@@ -55,14 +56,19 @@
         "watch:labextension": "jupyter labextension watch ."
     },
     "dependencies": {
+        "@codemirror/lang-python": "^6.2.1",
+        "@codemirror/merge": "^6.10.2",
+        "@codemirror/view": "^6.38.2",
         "@jupyterlab/application": "^4.0.0",
         "@jupyterlab/cells": "^4.0.0",
         "@jupyterlab/codeeditor": "^4.0.0",
+        "@jupyterlab/codemirror": "^4.4.7",
         "@jupyterlab/coreutils": "^6.0.0",
         "@jupyterlab/notebook": "^4.0.0",
         "@jupyterlab/services": "^7.0.0",
         "@jupyterlab/ui-components": "^4.0.0",
         "@lumino/widgets": "^2.0.0",
+        "codemirror": "^6.0.2",
         "jupyterlab-cell-input-footer": "^0.3.0",
         "nbdime": "^7.0.1"
     },

pyproject.toml

@@ -25,8 +25,8 @@ classifiers = [
 dependencies = [
     "nbdime",
     "jupyter_server>=2.4.0,<3",
-    "jupyterlab-eventlistener>=0.4.0",
-    "jupyterlab-cell-input-footer>=0.2.0"
+    "jupyterlab-eventlistener>=0.4.0,<0.5",
+    "jupyterlab-cell-input-footer>=0.3.1,<0.4"
 ]
 dynamic = ["version", "description", "authors", "urls", "keywords"]
 

src/diff/codemirror.ts

@@ -0,0 +1,111 @@
+import { python } from '@codemirror/lang-python';
+import { MergeView } from '@codemirror/merge';
+import { EditorView } from '@codemirror/view';
+import { jupyterTheme } from '@jupyterlab/codemirror';
+import { Message } from '@lumino/messaging';
+import { Widget } from '@lumino/widgets';
+import { basicSetup } from 'codemirror';
+import { IDiffWidgetOptions, BaseDiffWidget } from '../widget';
+
+/**
+ * A Lumino widget that contains a CodeMirror diff view
+ */
+class CodeMirrorDiffWidget extends BaseDiffWidget {
+  /**
+   * Construct a new CodeMirrorDiffWidget.
+   */
+  constructor(options: IDiffWidgetOptions) {
+    super(options);
+    this._originalCode = options.originalSource;
+    this._modifiedCode = options.newSource;
+    this.addClass('jp-DiffView');
+  }
+
+  /**
+   * Handle after-attach messages for the widget.
+   */
+  protected onAfterAttach(msg: Message): void {
+    super.onAfterAttach(msg);
+    this._createMergeView();
+  }
+
+  /**
+   * Handle before-detach messages for the widget.
+   */
+  protected onBeforeDetach(msg: Message): void {
+    this._destroyMergeView();
+    super.onBeforeDetach(msg);
+  }
+
+  /**
+   * Create the merge view with CodeMirror diff functionality.
+   */
+  private _createMergeView(): void {
+    if (this._mergeView) {
+      return;
+    }
+
+    this._mergeView = new MergeView({
+      a: {
+        doc: this._originalCode,
+        extensions: [
+          basicSetup,
+          python(),
+          EditorView.editable.of(false),
+          jupyterTheme
+        ]
+      },
+      b: {
+        doc: this._modifiedCode,
+        extensions: [
+          basicSetup,
+          python(),
+          EditorView.editable.of(false),
+          jupyterTheme
+        ]
+      },
+      parent: this.node
+    });
+  }
+
+  /**
+   * Destroy the merge view and clean up resources.
+   */
+  private _destroyMergeView(): void {
+    if (this._mergeView) {
+      this._mergeView.destroy();
+      this._mergeView = null;
+    }
+  }
+
+  private _originalCode: string;
+  private _modifiedCode: string;
+  private _mergeView: MergeView | null = null;
+}
+
+export async function createCodeMirrorDiffWidget(
+  options: IDiffWidgetOptions
+): Promise<Widget> {
+  const {
+    cell,
+    cellFooterTracker,
+    originalSource,
+    newSource,
+    showActionButtons = true,
+    openDiff = true
+  } = options;
+
+  const diffWidget = new CodeMirrorDiffWidget({
+    originalSource,
+    newSource,
+    cell,
+    cellFooterTracker,
+    showActionButtons,
+    openDiff
+  });
+
+  diffWidget.addClass('jupyterlab-cell-diff');
+  diffWidget.addToFooter();
+
+  return diffWidget;
+}