feat(@angular/cli): add a modernize MCP tool.

Author: amishne

packages/angular/cli/src/commands/mcp/mcp-server.ts

@@ -16,6 +16,7 @@ import { registerDocSearchTool } from './tools/doc-search';
 import { registerFindExampleTool } from './tools/examples';
 import { registerListProjectsTool } from './tools/projects';
 import { registerInstructionsResource } from './resources/instructions';
+import { registerModernizeTool } from './tools/modernize';
 
 export async function createMcpServer(
   context: {
@@ -37,6 +38,7 @@ export async function createMcpServer(
 
   registerInstructionsResource(server);
   registerBestPracticesTool(server);
+  registerModernizeTool(server);
 
   // If run outside an Angular workspace (e.g., globally) skip the workspace specific tools.
   if (context.workspace) {

packages/angular/cli/src/commands/mcp/tools/modernize.ts

@@ -0,0 +1,98 @@
+import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
+import { SchematicTestRunner, UnitTestTree } from '@angular-devkit/schematics/testing';
+import { Tree } from '@angular-devkit/schematics';
+import { z } from 'zod';
+import path from 'node:path';
+
+export function registerModernizeTool(server: McpServer): void {
+  server.registerTool(
+    'modernize',
+    {
+      title: 'Modernize Angular Code',
+      description:
+        'Runs migrations on Angular code to make it more modern and idiomatic. ' +
+        'This tool should be run when creating new Angular code, or when existing Angular code needs to be updated. ' +
+        'It can apply transformations for things like control flow, self-closing tags, and dependency injection.',
+      inputSchema: {
+        files: z.array(
+          z.object({
+            name: z.string().describe('The name of the file.'),
+            content: z.string().describe('The content of the file.'),
+          }),
+        ),
+      },
+      outputSchema: {
+        files: z.array(
+          z.object({
+            name: z.string().describe('The name of the file.'),
+            content: z.string().describe('The updated content of the file.'),
+          }),
+        ),
+      },
+    },
+    async (input) => {
+      try {
+        const migrationRunner = new SchematicTestRunner(
+          '@angular/core',
+          path.join(
+            __dirname,
+            '../../../../../../node_modules/@angular/core/schematics/migrations.json',
+          ),
+        );
+
+        const collectionRunner = new SchematicTestRunner(
+          '@angular/core',
+          path.join(
+            __dirname,
+            '../../../../../../node_modules/@angular/core/schematics/collection.json',
+          ),
+        );
+
+        let tree: Tree = new UnitTestTree(Tree.empty());
+        for (const file of input.files) {
+          tree.create(file.name, file.content);
+        }
+
+        for (const file of input.files) {
+          if (file.name.endsWith('.ts')) {
+            tree = await migrationRunner.runSchematic('test-bed-get', {}, tree);
+            tree = await migrationRunner.runSchematic('inject-flags', {}, tree);
+          } else if (file.name.endsWith('.html') || file.name.endsWith('.ng.html')) {
+            tree = await migrationRunner.runSchematic('control-flow-migration', {}, tree);
+            tree = await collectionRunner.runSchematic('self-closing-tags-migration', {}, tree);
+          }
+        }
+
+        const updatedFiles = input.files.map((file) => {
+          const updatedContent = tree.read(file.name)?.toString() ?? file.content;
+          return {
+            name: file.name,
+            content: updatedContent,
+          };
+        });
+
+        return {
+          content: [
+            {
+              type: 'text' as const,
+              text: 'Modernization migrations applied successfully.',
+            },
+          ],
+          structuredContent: {
+            files: updatedFiles,
+          },
+        };
+      } catch (e) {
+        const message = e instanceof Error ? e.message : 'An unknown error occurred.';
+        return {
+          content: [
+            {
+              type: 'text' as const,
+              text: `Failed to run modernization migrations: ${message}`,
+            },
+          ],
+        };
+      }
+    },
+  );
+}