vinext check

vinext check [options]

vinext check

  Scanning project...

  vinext compatibility report
  ========================================

  Imports: 8/10 fully supported
    ✓  next/link
    ✓  next/navigation (3 files)
    ✓  next/headers
    ✓  next/server
    ~  next/image — uses @unpic/react (no local optimization yet)
    ~  next/font/google — fonts loaded from CDN, not self-hosted
    ✗  next/amp — AMP is not supported

  Config: 5/6 options supported
    ✓  redirects
    ✓  rewrites
    ✓  headers
    ✓  i18n
    ~  images — remotePatterns validated, no local optimization
    ✗  webpack — Vite replaces webpack — custom webpack configs need migration

  Libraries: 4/5 compatible
    ✓  next-themes
    ✓  nuqs
    ✓  tailwindcss
    ✓  zod
    ✗  next-auth — relies on Next.js API route internals; consider migrating to better-auth

  Project structure:
    ✓  App Router (app/)
    ✓  15 page(s)
    ✓  3 layout(s)
    ✓  2 route handler(s)
    ✓  Custom _app
    ✗  Missing "type": "module" in package.json — required for Vite — vinext init will add it automatically

  ────────────────────────────────────────
  Overall: 82% compatible (22 supported, 3 partial, 3 issues)

  Issues to address:
    ✗  next/amp — AMP is not supported
    ✗  webpack — Vite replaces webpack — custom webpack configs need migration
    ✗  next-auth — relies on Next.js API route internals; consider migrating to better-auth

  Partial support (may need attention):
    ~  next/image — uses @unpic/react (no local optimization yet)
    ~  next/font/google — fonts loaded from CDN, not self-hosted
    ~  images — remotePatterns validated, no local optimization

  Recommended next steps:
    Run vinext init to set up your project automatically

  Or manually:
    1. Add "type": "module" to package.json
    2. Install: npm install -D vinext vite @vitejs/plugin-rsc
    3. Create vite.config.ts (see docs)
    4. Run: npx vite dev

// From check.ts:137-194
export function scanImports(root: string): CheckItem[] {
  const files = findSourceFiles(root);
  const importUsage = new Map<string, string[]>();

  const importRegex = /(?:import\s+(?:[\w{},\s*]+\s+from\s+)?|require\s*\()['"]([^'"]+)['"]\)?/g;
  // Skip `import type` — they're erased at compile time
  const typeOnlyImportRegex = /import\s+type\s+/;

  for (const file of files) {
    const content = fs.readFileSync(file, "utf-8");
    let match;
    while ((match = importRegex.exec(content)) !== null) {
      const mod = match[1];
      // Skip type-only imports (no runtime effect)
      const lineStart = content.lastIndexOf("\n", match.index) + 1;
      const line = content.slice(lineStart, match.index + match[0].length);
      if (typeOnlyImportRegex.test(line)) continue;
      
      // Only track next/* imports
      if (mod.startsWith("next/") || mod === "next" || mod === "server-only" || mod === "client-only") {
        if (!importUsage.has(mod)) importUsage.set(mod, []);
        importUsage.get(mod)!.push(path.relative(root, file));
      }
    }
  }

  // Map to support status
  return importUsage.entries().map(([mod, files]) => {
    const support = IMPORT_SUPPORT[mod];
    return {
      name: mod,
      status: support?.status ?? "unsupported",
      detail: support?.detail,
      files,
    };
  });
}

// From check.ts:199-259
export function analyzeConfig(root: string): CheckItem[] {
  const configFiles = ["next.config.ts", "next.config.mjs", "next.config.js", "next.config.cjs"];
  let configPath: string | null = null;
  for (const f of configFiles) {
    const p = path.join(root, f);
    if (fs.existsSync(p)) { configPath = p; break; }
  }

  if (!configPath) {
    return [{ name: "next.config", status: "supported", detail: "no config file found (defaults are fine)" }];
  }

  const content = fs.readFileSync(configPath, "utf-8");
  const items: CheckItem[] = [];

  // Check for known config options by searching for property names
  const configOptions = [
    "basePath", "trailingSlash", "redirects", "rewrites", "headers",
    "i18n", "env", "images", "output", "transpilePackages", "webpack",
    "reactStrictMode", "poweredByHeader",
  ];

  for (const opt of configOptions) {
    const regex = new RegExp(`\\b${opt}\\b`);
    if (regex.test(content)) {
      const support = CONFIG_SUPPORT[opt];
      items.push({ name: opt, status: support.status, detail: support.detail });
    }
  }
  
  // Check experimental options
  // ...
  
  return items;
}

// From check.ts:264-289
export function checkLibraries(root: string): CheckItem[] {
  const pkgPath = path.join(root, "package.json");
  if (!fs.existsSync(pkgPath)) return [];

  const pkg = JSON.parse(fs.readFileSync(pkgPath, "utf-8"));
  const allDeps = { ...pkg.dependencies, ...pkg.devDependencies };
  const items: CheckItem[] = [];

  for (const [lib, support] of Object.entries(LIBRARY_SUPPORT)) {
    if (allDeps[lib]) {
      items.push({
        name: lib,
        status: support.status,
        detail: support.detail,
      });
    }
  }

  return items;
}

// From check.ts:294-424
export function checkConventions(root: string): CheckItem[] {
  const items: CheckItem[] = [];

  // Check for pages/ and app/ directories
  const pagesDir = findPagesDir(root);
  const appDir = findAppDir(root);
  
  if (pagesDir) {
    items.push({ name: "Pages Router (pages/)", status: "supported" });
    
    // Count pages, API routes
    const pageFiles = findSourceFiles(pagesDir);
    const pages = pageFiles.filter(f => !f.includes("/api/"));
    const apiRoutes = pageFiles.filter(f => f.includes("/api/"));
    
    items.push({ name: `${pages.length} page(s)`, status: "supported" });
    if (apiRoutes.length) {
      items.push({ name: `${apiRoutes.length} API route(s)`, status: "supported" });
    }
    
    // Check for _app, _document
    // ...
  }
  
  if (appDir) {
    items.push({ name: "App Router (app/)", status: "supported" });
    
    // Count pages, layouts, route handlers, loading/error boundaries
    // ...
  }
  
  // Check for middleware.ts or proxy.ts
  // ...
  
  // Check for "type": "module" in package.json
  // ...
  
  return items;
}

npm install better-auth

{
  "type": "module"
}

vinext init
# Runs vinext check first
# Shows compatibility report
# Then proceeds with migration

vinext init --skip-check