A JavaScript framework for building backends with annotations.

Description

AnnotatedJS is a lightweight framework for building JavaScript backends. It is built with TypeScript and favors configuration over convention. This design allows it the flexibility to operate in different runtimes such as Web Workers, Service Workers, and Node.js.

The framework is heavily inspired by Spring and NestJS.

Documentation

Full documentation can be found on the GitHub page

Decorators

This framework relies on the decorators experimental JavaScript feature. It is recommended to use Babel to compile codebases that include AnnotatedJS.

Installation

Create a GitHub Personal Access Token and use it to login to npm via:

npm login --scope=@fork-git-it --registry=https://npm.pkg.github.com
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Then proceed to install the npm package via:

npm install @fork-git-it/annotatedjs
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Example

A trivial example of a local storage API in a service worker

// workerConfig.ts
import { Config } from "@fork-git-it/annotatedjs";
import { Router as IttyRouter } from "itty-router";

@Config()
export class WorkerConfig {
  @Property("IttyRouter")
  getIttyRouter() {
    return IttyRouter();
  }
}
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// localDatastore.ts
import { AnnotatedDatastore, Datastore } from "@fork-git-it/annotatedjs";

@Datastore()
class LocalDatastore implements AnnotatedDatastore<string> {
  length: number;

  async clear(): Promise<undefined> {
    localStorage.clear();
    this.length = localStorage.length;
  }

  async getItem(keyName: string): Promise<string | null> {
    return localStorage.getItem(keyName);
  }

  async key(index: number): Promise<string | null> {
    return localStorage.key(index);
  }

  async removeItem(keyName: string): Promise<undefined> {
    localStorage.removeItem(keyName);
    this.length = localStorage.length;
  }

  async setItem(keyName: string, value: string): Promise<undefined> {
    localStorage.setItem(keyName, value);
    this.length = localStorage.length;
  }
}
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// workerRouter.ts
import { AnnotatedRouter, Router } from "@fork-git-it/annotatedjs";
import { type RouterType } from "itty-router";

@Router()
class WorkerRouter implements AnnotatedRouter {
  @Inject("IttyRouter")
  private accessor ittyRouter: RouterType;

  options(uri: string, handler: RequestHandler): AnnotatedRouter {
    this.ittyRouter.options(uri, handler);
    return this;
  }

  head(uri: string, handler: RequestHandler): AnnotatedRouter {
    this.ittyRouter.head(uri, handler);
    return this;
  }

  get(uri: string, handler: RequestHandler): AnnotatedRouter {
    this.ittyRouter.get(uri, handler);
    return this;
  }

  put(uri: string, handler: RequestHandler): AnnotatedRouter {
    this.ittyRouter.put(uri, handler);
    return this;
  }

  post(uri: string, handler: RequestHandler): AnnotatedRouter {
    this.ittyRouter.post(uri, handler);
    return this;
  }

  patch(uri: string, handler: RequestHandler): AnnotatedRouter {
    this.ittyRouter.patch(uri, handler);
    return this;
  }

  delete(uri: string, handler: RequestHandler): AnnotatedRouter {
    this.ittyRouter.delete(uri, handler);
    return this;
  }

  all(uri: string, handler: RequestHandler): AnnotatedRouter {
    this.ittyRouter.all(uri, handler);
    return this;
  }

  handle(request: Request) {
    return this.ittyRouter.handle(request);
  }
}
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// storageService.ts
import { AnnotatedDatastore, Inject, Service } from "@fork-git-it/annotatedjs";
import { LocalDatastore } from "./localDatastore";

@Service()
export class StorageService {
  @Inject(LocalDatastore)
  private accessor datastore: AnnotatedDatastore<string>;

  async create(key: string, value: any) {
    await this.datastore.setItem(key, JSON.stringify(value));
  }

  async read(key: string) {
    const value = await this.datastore.getItem(key);
    if (!value) throw new Error(`no value for ${key} in storage`);
    return JSON.parse(value);
  }

  async update(key: string, value: any) {
    await this.datastore.setItem(key, JSON.stringify(value));
  }

  async delete(key: string) {
    await this.datastore.removeItem(key);
  }
}
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// workerCacheStorage.ts
import { AnnotatedCacheStorage, CacheStorage } from "@fork-git-it/annotatedjs";

@CacheStorage()
class WorkerCacheStorage implements AnnotatedCacheStorage {
  has(cacheName: string): Promise<boolean> {
    return caches.has(cacheName);
  }

  async open(cacheName: string): Promise<AnnotatedCache> {
    return caches.open(cacheName);
  }

  async delete(cacheName: string): Promise<boolean> {
    return caches.delete(cacheName);
  }
}
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// storageController.ts
import {
  Cache,
  Controller,
  Get,
  Purge,
  Put,
  Delete,
} from "@fork-git-it/annotatedjs";
import { StorageService } from "./storageService";

@Controller("/storage")
export class StorageController {
  @Inject(StorageService)
  private accessor storageService: StorageService;

  @Cache("storageCache")
  @Get("/:key")
  async get(req: Request): Promise<Response> {
    const ittyRequest: IRequest = <IRequest>req;
    try {
      const value = this.storageService.read(ittyRequest.params.key);
      return new Response(JSON.stringify(value));
    } catch (e) {
      return new Response(JSON.stringify(e), { status: 400 });
    }
  }

  @Purge("storageCache")
  @Put("/:key")
  async put(req: Request): Promise<Response> {
    const ittyRequest: IRequest = <IRequest>req;
    const value = await req.json();
    this.storageService.update(ittyRequest.params.key, value);
    return new Response(null, { status: 204 });
  }

  @Purge("storageCache")
  @Delete("/:key")
  async delete(req: Request): Promise<Response> {
    const ittyRequest: IRequest = <IRequest>req;
    this.storageService.delete(ittyRequest.params.key);
    return new Response(null, { status: 204 });
  }
}
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// index.ts

import { initialize } from "@fork-git-it/annotatedjs";
import "./workerConfig";
import "./localDatastore";
import "./storageController";

const requestHandler = initialize();
const eventHandler = (evt: Event) => {
  evt.respondWith(requestHandler(evt.request));
};
addEventListener("fetch", eventHandler);
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Containers

AnnotatedJS utilizes a container object to store globally configured values. The framework sets up a container by default but the initialize function and class-level annotations also accept a container object as an argument. This means that multiple containers can be configured if necessary. The container TypeScript type is Record<string, unknown>.

Attributions

Icons made by Pixel perfect from www.flaticon.com

License

AnnotatedJS is MIT licensed.