stacks-middleware

# Stacks Middleware Built into `@stacksjs/router`. Middleware intercepts requests before they reach route handlers. ## Key Paths - Middleware class: `storage/framework/core/router/src/middleware.ts` - Execution engine: `storage/framework/core/router/src/stacks-router.ts` - Alias registry: `app/Middleware.ts` - Default middleware: `storage/framework/defaults/app/Middleware/` (22 files) - Auth middleware (standalone): `storage/framework/core/auth/src/middleware.ts` - Tests: `storage/framework/core/router/tests/middleware.test.ts` ## Middleware Class ```typescript import { Middleware } from '@stacksjs/router' export interface MiddlewareConfig { name: string priority?: number // Lower = runs first, default: 10 handle: (request: EnhancedRequest) => void | Promise<void> } export class Middleware { readonly name: string readonly priority: number readonly handle: (request: EnhancedRequest) => void | Promise<void> constructor(config: MiddlewareConfig) } ``` ## Creating Custom Middleware Create a file in `app/Middleware/`: ```typescript // app/Middleware/RateLimit.ts import { Middleware } from '@stacksjs/router' export default new Middleware({ name: 'RateLimit', priority: 2, async handle(request) { // Throw to short-circuit the request // throw new HttpError(429, 'Too many requests') // Return void to continue to next middleware }, }) ``` ### Short-Circuiting Middleware can stop request processing by: 1. **Throwing an Error with `statusCode`** — converted to HTTP error response 2. **Throwing a Response** — returned directly to client 3. **Returning void** — continues to next middleware ```typescript // Error with status code const error = new Error('Unauthorized') as Error & { statusCode: number } error.statusCode = 401 throw error // Direct Response (full control) throw new Response(JSON.stringify({ error: 'Rate limited' }), { status: 429, headers: { 'Retry-After': '60' }, }) ``` ## Alias Registry (app/Middleware.ts) Maps short names to middleware class filenames: ```typescript import { defineMiddleware } from '@stacksjs/router' export default defineMiddleware({ 'maintenance': 'Maintenance', 'auth': 'Auth', 'guest': 'Guest', 'api': 'Api', 'team': 'Team', 'site': 'Site', 'logger': 'Logger', 'abilities': 'Abilities', 'can': 'Can', 'throttle': 'Throttle', 'signed': 'Signed', 'env': 'Env', 'env:local': 'EnvLocal', 'env:development': 'EnvDevelopment', 'env:dev': 'EnvDevelopment', 'env:staging': 'EnvStaging', 'env:production': 'EnvProduction', 'env:prod': 'EnvProduction', 'role': 'Role', 'permission': 'Permission', 'verified': 'EnsureEmailIsVerified', }) ``` The alias is yours to invent; the class name is checked against `app/Middleware/` and the framework defaults, so `{ auth: 'Auht' }` is a compile error rather than a route whose guard resolves to nothing. This map is **merged over** the framework defaults, not a replacement for them, so an alias Stacks adds later is available without editing the file. ## Reference forms Three shapes are read off a reference, in this order: | Written | Means | |---|---| | `'auth'` | the alias, or a class name if no alias matches (`'signed'` → `Signed`) | | `'!auth'` | inverted: the route passes only when `auth` refuses | | `'throttle:60,1'` | `throttle` with `60,1` in `request._middlewareParams.throttle` | The **whole** reference is looked up as an alias before the colon is treated as a parameter separator. That is what makes `'env:production'` its own alias rather than `env` with a parameter - `Env` ignores parameters and accepts every known environment, so splitting first turned a production-only route into an unguarded one. Inversion counts a `Response` or a status-carrying error as a refusal, and nothing else. A `TypeError` from a bug inside `Auth` is a crash, not a declination, and must not let `!auth` through. ## Applying Middleware ### Per-Route (Chainable) ```typescript route.get('/dashboard', 'DashboardAction') .middleware('auth') .middleware('verified') .name('dashboard.show') ``` ### Route Groups ```typescript route.group({ prefix: '/api/v1', middleware: ['auth', 'throttle'] }, () => { route.get('/users', listUsers) route.post('/users', createUser) }) ``` Group middleware is prepended to all routes inside the callback. Groups can be nested — middleware accumulates. ### Parameterized Middleware Pass parameters using colon syntax: ```typescript route.get('/admin', handler).middleware('throttle:60,1') // 60 requests per 1 minute route.get('/posts', handler).middleware('abilities:read,write') route.get('/settings', handler).middleware('role:admin,editor') route.get('/posts/{id}', handler).middleware('can:update,post') ``` Parameters are stored on `request._middlewareParams[middlewareName]` and parsed by the middleware's `handle` function. ## Default Middleware Reference | Alias | Class | Priority | Description | |-------|-------|----------|-------------| | `maintenance` | Maintenance | 0 | Checks maintenance mode, supports secret bypass URL and IP allowlist | | `auth` | Auth | 1 | Validates bearer token, sets authenticated user on request | | `api` | Api | 1 | Validates request accepts JSON | | `guest` | Guest | 1 | Ensures user is NOT authenticated (for login/register pages) | | `env` | Env | 1 | Checks current environment | | `logger` | Logger | 2 | Logs request method and URL | | `abilities` | Abilities | 2 | Checks token abilities/scopes (parameterized: `abilities:read,write`) | | `can` | Can | 3 | Authorization gate (parameterized: `can:update,post`) | | `role` | Role | 3 | Checks user roles (parameterized: `role:admin`) | | `permission` | Permission | 3 | Checks user permissions (parameterized: `permission:edit-posts`) | | `team` | Team | 3 | Ensures user belongs to a team (parameterized: `team:teamId`) | | `verified` | EnsureEmailIsVerified | 4 | Verifies email is confirmed | | `throttle` | Throttle | — | Rate limiting (parameterized: `throttle:60,1` or `throttle:100,5m`) | | `env:local` | EnvLocal | — | Only allows local environment | | `env:development` / `env:dev` | EnvDevelopment | — | Only allows development | | `env:staging` | EnvStaging | — | Only allows staging | | `env:production` / `env:prod` | EnvProduction | — | Only allows production | ### Environment Negation Variants `EnvNotLocal`, `EnvNotDevelopment`, `EnvNotStaging` and `EnvNotProduction` exist as classes with no alias. Reference them by class name, or write the negated form of the positive alias - `'!env:production'` is `EnvNotProduction`. ## Middleware Loading Flow ``` 1. Strip a leading '!', if any, and remember it 2. Look the WHOLE remainder up in the merged alias map 'env:production' is an alias → { name: 'env:production' } 'throttle:60,1' is not → { name: 'throttle', params: '60,1' } 3. Check middleware cache (loaded once, cached for performance) 4. Resolve alias: 'throttle' → 'Throttle'; unaliased names PascalCase 5. Try loading from app/Middleware/Throttle.ts (user overrides) 6. Fall back to storage/framework/defaults/app/Middleware/Throttle.ts 7. Store params on request: request._middlewareParams.throttle = '60,1' 8. Wrap in the inverter if step 1 saw a '!' 9. Sort the chain by priority, then execute: await middleware.handle(req) ``` User middleware in `app/Middleware/` always takes precedence over framework defaults. ## Representative Implementations ### Auth Middleware ```typescript export default new Middleware({ name: 'Auth', priority: 1, async handle(request) { const bearerToken = request.bearerToken() if (!bearerToken) throw new HttpError(401, 'Unauthorized. No token provided.') const isValid = await Auth.validateToken(bearerToken) if (!isValid) throw new HttpError(401, 'Unauthorized. Invalid token.') }, }) ``` ### Maintenance Middleware ```typescript export default new Middleware({ name: 'Maintenance', priority: 0, async handle(request) { if (!(await isDownForMaintenance())) return const payload = await maintenancePayload() // Check secret bypass URL → set cookie and redirect // Check bypass cookie or allowed IP → continue // Otherwise → throw maintenance response }, }) ``` ### Throttle Middleware (Parameterized) ```typescript // '60,1' = 60 requests per 1 minute // '100,5m' = 100 requests per 5 minutes // '1000,1h' = 1000 requests per hour async handle(request) { const params = request._middlewareParams?.throttle || '60,1' const config = parseThrottleString(params) const limiter = createRateLimitMiddleware(config) // Returns 429 if rate limit exceeded } ``` ## Standalone Auth Middleware (@stacksjs/auth) A separate, more complete auth middleware exists: ```typescript import { authMiddleware, authMiddlewareHandler } from '@stacksjs/auth' // Checks both request.bearerToken() and raw Authorization header // Calls Auth.getUserFromToken() to validate // Sets Auth.setUser(user) and request._authenticatedUser // Loads current access token onto request._currentAccessToken ``` ## Gotchas - **Priority DOES order the chain** — entries are sorted by `priority` (lower first, default 10) before execution, so CORS can precede auth regardless of the order they were attached in. An earlier version of this file said otherwise. A non-finite or negative value is clamped to the default and warned about once - **`terminate()` doesn't exist** — some docs reference it, but it's not in the actual `MiddlewareConfig` interface - **Two auth middleware implementations** — defaults version (basic token check) and `@stacksjs/auth` version (full user loading) - **EnvNot* files have no aliases** — reachable by class name, or as `'!env:production'` and friends - **The alias map merges over the defaults** — an app's `app/Middleware.ts` adds to and overrides them rather than replacing the set - **Middleware is cached after first load** — changes require server restart - **User overrides take precedence** — `app/Middleware/Auth.ts` replaces the framework default completely - **Group middleware accumulates** — nested groups combine all parent middleware - **Request body parsed before middleware** — Laravel-style methods (`.input()`, `.query`, `.file()`) are available in middleware