feat(framework): add framework detection and shim functionality for Vue and Astro

Author: naokihaba

packages/cli/src/migration/migrator.ts

@@ -683,6 +683,88 @@ function cleanupDeprecatedTsconfigOptions(
   }
 }
 
+// Svelte is intentionally excluded: @sveltejs/vite-plugin-svelte and svelte-check handle
+// .svelte file types automatically. No env.d.ts shim is needed or documented officially.
+// https://svelte.dev/docs/svelte/typescript
+export type Framework = 'vue' | 'astro';
+
+const FRAMEWORK_SHIMS: Record<Framework, string> = {
+  // https://vuejs.org/guide/typescript/overview#volar-takeover-mode
+  vue: [
+    "declare module '*.vue' {",
+    "  import type { DefineComponent } from 'vue';",
+    '  const component: DefineComponent<{}, {}, unknown>;',
+    '  export default component;',
+    '}',
+  ].join('\n'),
+  // astro/client is the pre-v4.14 form; v4.14+ prefers `/// <reference path="../.astro/types.d.ts" />`
+  // but .astro/types.d.ts is generated at build time and may not exist yet after migration.
+  // astro/client remains valid and is still used in official Astro integrations.
+  // https://docs.astro.build/en/guides/typescript/#extending-global-types
+  astro: '/// <reference types="astro/client" />',
+};
+
+export function detectFramework(projectPath: string): Framework | null {
+  const packageJsonPath = path.join(projectPath, 'package.json');
+  if (!fs.existsSync(packageJsonPath)) {
+    return null;
+  }
+  const pkg = readJsonFile(packageJsonPath) as {
+    dependencies?: Record<string, string>;
+    devDependencies?: Record<string, string>;
+  };
+  const allDeps = { ...pkg.dependencies, ...pkg.devDependencies };
+  for (const framework of ['vue', 'astro'] as const) {
+    if (allDeps[framework]) {
+      return framework;
+    }
+  }
+  return null;
+}
+
+function getEnvDtsPath(projectPath: string): string {
+  const srcEnvDts = path.join(projectPath, 'src', 'env.d.ts');
+  const rootEnvDts = path.join(projectPath, 'env.d.ts');
+  for (const candidate of [srcEnvDts, rootEnvDts]) {
+    if (fs.existsSync(candidate)) {
+      return candidate;
+    }
+  }
+  return fs.existsSync(path.join(projectPath, 'src')) ? srcEnvDts : rootEnvDts;
+}
+
+export function hasFrameworkShim(projectPath: string, framework: Framework): boolean {
+  const envDtsPath = getEnvDtsPath(projectPath);
+  if (!fs.existsSync(envDtsPath)) {
+    return false;
+  }
+
+  const content = fs.readFileSync(envDtsPath, 'utf-8');
+  if (framework === 'astro') {
+    return content.includes('astro/client');
+  }
+  return content.includes(`'*.${framework}'`) || content.includes(`"*.${framework}"`);
+}
+
+export function addFrameworkShim(
+  projectPath: string,
+  framework: Framework,
+  report?: MigrationReport,
+): void {
+  const envDtsPath = getEnvDtsPath(projectPath);
+  const shim = FRAMEWORK_SHIMS[framework];
+  if (fs.existsSync(envDtsPath)) {
+    const existing = fs.readFileSync(envDtsPath, 'utf-8');
+    fs.writeFileSync(envDtsPath, `${existing.trimEnd()}\n\n${shim}\n`, 'utf-8');
+  } else {
+    fs.mkdirSync(path.dirname(envDtsPath), { recursive: true });
+    fs.writeFileSync(envDtsPath, `${shim}\n`, 'utf-8');
+  }
+  if (report) {
+    report.frameworkShimAdded = true;
+  }
+}
+
 /**
  * Rewrite standalone project to add vite-plus dependencies
  * @param projectPath - The path to the project