fix: resolve duplicate package issues in CRDT demos

- blocknote-demo: Add webpack alias for y-prosemirror to fix
  undoCommand/redoCommand import error, add missing @veltdev/react dep
- codemirror-crdt-demo: Add webpack aliases for @codemirror/state,
  @codemirror/view, yjs, y-codemirror.next, lib0 to prevent duplicates
- tiptap-crdt-demo: Add webpack aliases for yjs, y-prosemirror, lib0
  to prevent duplicate Yjs instance errors

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: yoen-velt

apps/react/crdt/text-editors/blocknote/blocknote-demo/next.config.js

@@ -1,4 +1,14 @@
 /** @type {import('next').NextConfig} */
-const nextConfig = {}
+const nextConfig = {
+  transpilePackages: ['@blocknote/core', '@blocknote/react', '@blocknote/mantine', 'y-prosemirror'],
+  webpack: (config) => {
+    // Ensure y-prosemirror is properly resolved to avoid duplicate instances
+    config.resolve.alias = {
+      ...config.resolve.alias,
+      'y-prosemirror': require.resolve('y-prosemirror'),
+    }
+    return config
+  },
+}
 
 module.exports = nextConfig

apps/react/crdt/text-editors/blocknote/blocknote-demo/package.json

@@ -22,6 +22,7 @@
     "@tiptap/extension-text-style": "^2.26.4",
     "@tiptap/pm": "^2.26.4",
     "@veltdev/blocknote-crdt-react": "4.5.0-beta.3",
+    "@veltdev/react": "^4.6.10",
     "clsx": "^2.1.1",
     "next": "^15.5.7",
     "react": "^19.2.0",

apps/react/crdt/text-editors/codemirror/codemirror-crdt-demo/next.config.js

@@ -1,6 +1,24 @@
 /** @type {import('next').NextConfig} */
 const path = require('path');
 
+// Helper to get package directory from main entry
+const getPackageDir = (packageName) => {
+  try {
+    // Try resolving the main entry and get its directory
+    const resolved = require.resolve(packageName);
+    // Walk up to find the package root (contains node_modules or is in node_modules)
+    let dir = path.dirname(resolved);
+    while (dir !== '/' && !dir.endsWith(`node_modules/${packageName}`) && !dir.endsWith(`node_modules\\${packageName}`)) {
+      const parent = path.dirname(dir);
+      if (parent === dir) break;
+      dir = parent;
+    }
+    return dir;
+  } catch {
+    return packageName;
+  }
+};
+
 // List of domains allowed to embed this app in an iframe
 const allowList = [
   "'self'",
@@ -14,12 +32,17 @@ const EMBED_CSP = `frame-ancestors ${allowList}`;
 const nextConfig = {
   transpilePackages: ['@veltdev/react', '@veltdev/codemirror-crdt-react', '@veltdev/codemirror-crdt'],
   webpack: (config) => {
-    // Resolve @veltdev/react for peer dependencies when using npm
-    // Get the package directory, not just the entry file
-    const veltReactPath = path.dirname(require.resolve('@veltdev/react/package.json'));
+    // Resolve packages to single instances to prevent duplicate package issues
+    const veltReactPath = getPackageDir('@veltdev/react');
     config.resolve.alias = {
       ...config.resolve.alias,
       '@veltdev/react': veltReactPath,
+      // Ensure single instances of CodeMirror and Yjs packages
+      '@codemirror/state': getPackageDir('@codemirror/state'),
+      '@codemirror/view': getPackageDir('@codemirror/view'),
+      'yjs': getPackageDir('yjs'),
+      'y-codemirror.next': getPackageDir('y-codemirror.next'),
+      'lib0': getPackageDir('lib0'),
     };
     return config;
   },

apps/react/crdt/text-editors/tiptap/tiptap-crdt-demo/next.config.js

@@ -1,4 +1,37 @@
 /** @type {import('next').NextConfig} */
-const nextConfig = {}
+const path = require('path');
+
+// Helper to get package directory from main entry
+const getPackageDir = (packageName) => {
+  try {
+    // Try resolving the main entry and get its directory
+    const resolved = require.resolve(packageName);
+    // Walk up to find the package root (contains node_modules or is in node_modules)
+    let dir = path.dirname(resolved);
+    while (dir !== '/' && !dir.endsWith(`node_modules/${packageName}`) && !dir.endsWith(`node_modules\\${packageName}`)) {
+      const parent = path.dirname(dir);
+      if (parent === dir) break;
+      dir = parent;
+    }
+    return dir;
+  } catch {
+    return packageName;
+  }
+};
+
+const nextConfig = {
+  transpilePackages: ['@veltdev/react', '@veltdev/tiptap-crdt-react', '@veltdev/tiptap-crdt'],
+  webpack: (config) => {
+    // Resolve packages to single instances to prevent duplicate package issues
+    config.resolve.alias = {
+      ...config.resolve.alias,
+      // Ensure single instances of Yjs packages
+      'yjs': getPackageDir('yjs'),
+      'y-prosemirror': getPackageDir('y-prosemirror'),
+      'lib0': getPackageDir('lib0'),
+    };
+    return config;
+  },
+}
 
 module.exports = nextConfig