10. Build-time checks and manifests

Status: Runnable. Everything on this page works today. The compiler is optional: apps run the same without it.

@avijs/compiler adds two checks you can run in CI or before a deploy. It ships an avi-compile command.

Checking static inject lists

With @Injectable or @Controller, TypeScript already checks that static inject matches the constructor. Plain classes only get a runtime check of the argument count. avi-compile check type-checks every static inject in a project, decorated or not:

avi-compile check --project tsconfig.json

src/users/users.repository.ts:4:20 error AVI004: UsersRepository.inject[0] provides Config, but parameter "db" expects Db
src/users/users.service.ts:9:19 error AVI001: UsersService needs 2 constructor arguments but inject lists 1
src/audit.ts:3:3 warning AVI002: Audit.inject is not an array literal and cannot be checked
2 error(s), 1 warning(s) in static inject lists

Code	Meaning
AVI001	The list is shorter than the constructor's required parameters
AVI002	The list is built at runtime (a function call, a spread), so it is skipped
AVI003	A token's type could not be worked out
AVI004	A token provides a type the parameter does not accept

The command exits with 1 when there are errors, so CI fails. Subtypes are fine, and optional parameters may be left out.

Manifests

A manifest is a JSON description of your app: modules, providers, exports and routes. It is built without creating any provider, so nothing connects to a database at build time.

tsc -b
avi-compile manifest dist/app.module.js --export AppModule --out avi.manifest.json

The command checks the module graph the same way init() does, so a missing provider or a cycle fails the build instead of the deploy. In code, the same description comes from describeApp:

import { describeApp } from '@avijs/core';

const manifest = describeApp(AppModule);
// manifest.routes → [{ method: 'GET', path: '/users/:id', module: 'UsersModule', controller: 'UsersController' }, ...]

Controllers whose routes come from a routes factory only know their routes at runtime. The manifest lists them under dynamic, and the CLI prints a note for each.

Refusing to start with a stale manifest

Pass the manifest to createAvi and init() compares it with the app it is about to start:

import manifest from './avi.manifest.json' with { type: 'json' };

const app = createAvi({ manifest }).register(AppModule);
await app.listen(3000);

If a route, provider or module changed since the manifest was written, startup fails and names the first difference, such as $.modules[0].controllers[1].routes[1]. Use this to make sure the artifact you reviewed is the one you deploy.

What the compiler does not do

The compiler does not generate code, and a manifest does not make startup faster: verifying it is extra work (see benchmarks/README.md). Generated provider factories are deferred until they show a measurable benefit; init() already takes a few milliseconds for 1,000 providers.

Next

Chapter 11: OpenAPI documents.