feat(@angular-devkit/schematics): add schematics to generate ai context files.

* `ng generate config ai` to prompt support tools.
* `ng generate config ai --tool=gemini` to specify the tool.

Supported ai tools: gemini, claude, copilot, windsurf, cursor.

Author: JeanMeche

goldens/public-api/angular_devkit/schematics/index.api.md

@@ -637,7 +637,10 @@ export enum MergeStrategy {
 export function mergeWith(source: Source, strategy?: MergeStrategy): Rule;
 
 // @public (undocumented)
-export function move(from: string, to?: string): Rule;
+export function move(from: string, to: string): Rule;
+
+// @public (undocumented)
+export function move(to: string): Rule;
 
 // @public (undocumented)
 export function noop(): Rule;

packages/angular_devkit/schematics/src/rules/move.ts

@@ -10,6 +10,8 @@ import { join, normalize } from '@angular-devkit/core';
 import { Rule } from '../engine/interface';
 import { noop } from './base';
 
+export function move(from: string, to: string): Rule;
+export function move(to: string): Rule;
 export function move(from: string, to?: string): Rule {
   if (to === undefined) {
     to = from;

packages/schematics/angular/config/files/__rulesName__.template

@@ -0,0 +1,54 @@
+<% if (frontmatter) { %><%= frontmatter %>
+
+<% } %>You are an expert in TypeScript, Angular, and scalable web application development. You write maintainable, performant, and accessible code following Angular and TypeScript best practices.
+
+## TypeScript Best Practices
+
+- Use strict type checking
+- Prefer type inference when the type is obvious
+- Avoid the `any` type; use `unknown` when type is uncertain
+
+## Angular Best Practices
+
+- Always use standalone components over NgModules
+- Must NOT set `standalone: true` inside Angular decorators. It's the default.
+- Use signals for state management
+- Implement lazy loading for feature routes
+- Do NOT use the `@HostBinding` and `@HostListener` decorators. Put host bindings inside the `host` object of the `@Component` or `@Directive` decorator instead
+- Use `NgOptimizedImage` for all static images.
+  - `NgOptimizedImage` does not work for inline base64 images.
+
+## Components
+
+- Keep components small and focused on a single responsibility
+- Use `input()` and `output()` functions instead of decorators
+- Use `computed()` for derived state
+- Set `changeDetection: ChangeDetectionStrategy.OnPush` in `@Component` decorator
+- Prefer inline templates for small components
+- Prefer Reactive forms instead of Template-driven ones
+- Do NOT use `ngClass`, use `class` bindings instead
+- DO NOT use `ngStyle`, use `style` bindings instead
+
+## State Management
+
+- Use signals for local component state
+- Use `computed()` for derived state
+- Keep state transformations pure and predictable
+- Do NOT use `mutate` on signals, use `update` or `set` instead
+
+## Templates
+
+- Keep templates simple and avoid complex logic
+- Use native control flow (`@if`, `@for`, `@switch`) instead of `*ngIf`, `*ngFor`, `*ngSwitch`
+- Use the async pipe to handle observables
+
+## Services
+
+- Design services around a single responsibility
+- Use the `providedIn: 'root'` option for singleton services
+- Use the `inject()` function instead of constructor injection
+
+## Common pitfalls
+
+- Control flow (`@if`):
+  - You cannot use `as` expressions in `@else if (...)`. E.g. invalid code: `@else if (bla(); as x)`.

packages/schematics/angular/config/index.ts

@@ -11,6 +11,7 @@ import {
   SchematicsException,
   apply,
   applyTemplates,
+  chain,
   filter,
   mergeWith,
   move,
@@ -24,12 +25,40 @@ import { getWorkspace as readWorkspace, updateWorkspace } from '../utility/works
 import { Builders as AngularBuilder } from '../utility/workspace-models';
 import { Schema as ConfigOptions, Type as ConfigType } from './schema';
 
+const geminiFile: ContextFileInfo = { rulesName: 'GEMINI.md', directory: '.gemini' };
+const copilotFile: ContextFileInfo = {
+  rulesName: 'copilot-instructions.md',
+  directory: '.github',
+};
+const claudeFile: ContextFileInfo = { rulesName: 'CLAUDE.md', directory: '.claude' };
+const windsurfFile: ContextFileInfo = {
+  rulesName: 'guidelines.md',
+  directory: path.join('.windsurf', 'rules'),
+};
+
+// Cursor file is a bit different, it has a front matter section.
+const cursorFile: ContextFileInfo = {
+  rulesName: 'cursor.mdc',
+  directory: path.join('.cursor', 'rules'),
+  frontmatter: `---\ncontext: true\npriority: high\nscope: project\n---`,
+};
+
+const AI_TOOLS = {
+  'gemini': geminiFile,
+  'claude': claudeFile,
+  'copilot': copilotFile,
+  'cursor': cursorFile,
+  'windsurf': windsurfFile,
+};
+
 export default function (options: ConfigOptions): Rule {
   switch (options.type) {
     case ConfigType.Karma:
       return addKarmaConfig(options);
     case ConfigType.Browserslist:
       return addBrowserslistConfig(options);
+    case ConfigType.Ai:
+      return addAiContextFile(options);
     default:
       throw new SchematicsException(`"${options.type}" is an unknown configuration file type.`);
   }
@@ -103,3 +132,40 @@ function addKarmaConfig(options: ConfigOptions): Rule {
     );
   });
 }
+
+interface ContextFileInfo {
+  rulesName: string;
+  directory: string;
+  frontmatter?: string;
+}
+
+function addAiContextFile(options: ConfigOptions): Rule {
+  const selectedTool = options.tool as keyof typeof AI_TOOLS;
+  const files: ContextFileInfo[] =
+    options.tool === 'all' ? Object.values(AI_TOOLS) : [AI_TOOLS[selectedTool]];
+
+  return async (host) => {
+    const workspace = await readWorkspace(host);
+    const project = workspace.projects.get(options.project);
+    if (!project) {
+      throw new SchematicsException(`Project name "${options.project}" doesn't not exist.`);
+    }
+
+    const rules = files.map(({ rulesName, directory, frontmatter }) =>
+      mergeWith(
+        apply(url('./files'), [
+          // Keep only the single source template
+          filter((p) => p.endsWith('__rulesName__.template')),
+          applyTemplates({
+            ...strings,
+            rulesName,
+            frontmatter: frontmatter ?? '',
+          }),
+          move(directory),
+        ]),
+      ),
+    );
+
+    return chain(rules);
+  };
+}

packages/schematics/angular/config/index_spec.ts

@@ -9,7 +9,7 @@
 import { SchematicTestRunner, UnitTestTree } from '@angular-devkit/schematics/testing';
 import { Schema as ApplicationOptions } from '../application/schema';
 import { Schema as WorkspaceOptions } from '../workspace/schema';
-import { Schema as ConfigOptions, Type as ConfigType } from './schema';
+import { Schema as ConfigOptions, Tool as ConfigTool, Type as ConfigType } from './schema';
 
 describe('Config Schematic', () => {
   const schematicRunner = new SchematicTestRunner(
@@ -32,12 +32,15 @@ describe('Config Schematic', () => {
   };
 
   let applicationTree: UnitTestTree;
-  function runConfigSchematic(type: ConfigType): Promise<UnitTestTree> {
+  function runConfigSchematic(type: ConfigType, tool?: ConfigTool): Promise<UnitTestTree>;
+  function runConfigSchematic(type: ConfigType.Ai, tool: ConfigTool): Promise<UnitTestTree>;
+  function runConfigSchematic(type: ConfigType, tool?: ConfigTool): Promise<UnitTestTree> {
     return schematicRunner.runSchematic<ConfigOptions>(
       'config',
       {
         project: 'foo',
         type,
+        tool,
       },
       applicationTree,
     );
@@ -97,4 +100,38 @@ describe('Config Schematic', () => {
       expect(tree.readContent('projects/foo/.browserslistrc')).toContain('Chrome >=');
     });
   });
+
+  describe(`when 'type' is 'ai'`, () => {
+    it('should create a GEMINI.MD file', async () => {
+      const tree = await runConfigSchematic(ConfigType.Ai, ConfigTool.Gemini);
+      expect(tree.readContent('.gemini/GEMINI.md')).toMatch(/^You are an expert in TypeScript/);
+    });
+
+    it('should create a copilot-instructions.md file', async () => {
+      const tree = await runConfigSchematic(ConfigType.Ai, ConfigTool.Copilot);
+      expect(tree.readContent('.github/copilot-instructions.md')).toContain(
+        'You are an expert in TypeScript',
+      );
+    });
+
+    it('should create a cursor file', async () => {
+      const tree = await runConfigSchematic(ConfigType.Ai, ConfigTool.Cursor);
+      const cursorFile = tree.readContent('.cursor/rules/cursor.mdc');
+      expect(cursorFile).toContain('You are an expert in TypeScript');
+      expect(cursorFile).toContain('context: true');
+      expect(cursorFile).toContain('---\n\nYou are an expert in TypeScript');
+    });
+
+    it('should create a windsurf file', async () => {
+      const tree = await runConfigSchematic(ConfigType.Ai, ConfigTool.Windsurf);
+      expect(tree.readContent('.windsurf/rules/guidelines.md')).toContain(
+        'You are an expert in TypeScript',
+      );
+    });
+
+    it('should create a claude file', async () => {
+      const tree = await runConfigSchematic(ConfigType.Ai, ConfigTool.Claude);
+      expect(tree.readContent('.claude/CLAUDE.md')).toContain('You are an expert in TypeScript');
+    });
+  });
 });

packages/schematics/angular/config/schema.json

@@ -16,13 +16,36 @@
     "type": {
       "type": "string",
       "description": "Specifies the type of configuration file to generate.",
-      "enum": ["karma", "browserslist"],
+      "enum": ["karma", "browserslist", "ai"],
       "x-prompt": "Which type of configuration file would you like to create?",
       "$default": {
         "$source": "argv",
         "index": 0
       }
+    },
+    "tool": {
+      "type": "string",
+      "description": "Specifies the AI tool to configure when type is 'ai'.",
+      "enum": ["gemini", "copilot", "claude", "cursor", "windsurf", "all", "none"]
     }
   },
-  "required": ["project", "type"]
+  "required": ["project", "type"],
+  "allOf": [
+    {
+      "if": {
+        "properties": {
+          "type": {
+            "not": {
+              "const": "ai"
+            }
+          }
+        }
+      },
+      "then": {
+        "not": {
+          "required": ["tool"]
+        }
+      }
+    }
+  ]
 }

packages/schematics/angular/ng-new/index.ts

@@ -23,6 +23,7 @@ import {
   RepositoryInitializerTask,
 } from '@angular-devkit/schematics/tasks';
 import { Schema as ApplicationOptions } from '../application/schema';
+import { Tool as AiTool, Schema as ConfigOptions, Type as ConfigType } from '../config/schema';
 import { Schema as WorkspaceOptions } from '../workspace/schema';
 import { Schema as NgNewOptions } from './schema';
 
@@ -60,11 +61,18 @@ export default function (options: NgNewOptions): Rule {
     zoneless: options.zoneless,
   };
 
+  const configOptions: ConfigOptions = {
+    project: options.name,
+    type: ConfigType.Ai,
+    tool: options.aiConfig as unknown as AiTool,
+  };
+
   return chain([
     mergeWith(
       apply(empty(), [
         schematic('workspace', workspaceOptions),
         options.createApplication ? schematic('application', applicationOptions) : noop,
+        options.aiConfig !== 'none' ? schematic('config', configOptions) : noop,
         move(options.directory),
       ]),
     ),

packages/schematics/angular/ng-new/index_spec.ts

@@ -103,4 +103,13 @@ describe('Ng New Schematic', () => {
     const { cli } = JSON.parse(tree.readContent('/bar/angular.json'));
     expect(cli.packageManager).toBe('npm');
   });
+
+  it('should add ai config file when aiConfig is set', async () => {
+    const options = { ...defaultOptions, aiConfig: 'gemini' };
+
+    const tree = await schematicRunner.runSchematic('ng-new', options);
+    const files = tree.files;
+    expect(files).toContain('/bar/.gemini/GEMINI.md');
+    expect(tree.readContent('/bar/.gemini/GEMINI.md')).toMatch(/^You are an expert in TypeScript/);
+  });
 });

packages/schematics/angular/ng-new/schema.json

@@ -144,6 +144,12 @@
       "x-prompt": "Do you want to create a 'zoneless' application without zone.js (Developer Preview)?",
       "type": "boolean",
       "default": false
+    },
+    "aiConfig": {
+      "description": "Create an AI configuration file for the project. This file is used to improve the outputs of AI tools by following the best practices.",
+      "default": "none",
+      "type": "string",
+      "enum": ["gemini", "copilot", "claude", "cursor", "windsurf", "all", "none"]
     }
   },
   "required": ["name", "version"]