Deco (deh · kow) is a lightweight helper library for Deno developers (still work in progress)

import { Http } from "../decorators/httpserver.decorator.ts";

@Http.Server({ schema: "api.yaml" })
class _OpenAPIServer {}

@Http.Server()
class _ExampleServer {
  @Http.Get("/api/:id")
  get({ id, url }: { id: string; url: URL }) {
    return {
      body: `[GET /api/:id] 😎 (got id: "${id}", query: "${
        decodeURIComponent(url.searchParams.toString())
      }")`,
    };
  }

  @Http.Post("/api")
  async post({ url, request }: { url: URL; request: Request }) {
    return {
      body: `[POST /api/:id] 😎 (got data: "${await request.text()}", query: "${
        decodeURIComponent(url.searchParams.toString())
      }")`,
    };
  }

  @Http.Get("/static/*")
  static({ "*": path }: { "*": string }) {
    return {
      body: `[GET /static/*] 😎 (got path: "${path}")`,
    };
  }

  @Http.Get("/sse")
  stream() {
    let cancelled = true;
    const stream = new ReadableStream({
      start: (controller) => {
        cancelled = false;
        console.log("Stream started");
        controller.enqueue(": Welcome to the /sse endpoint!\n\n");
        (function time() {
          setTimeout(() => {
            if (!cancelled) {
              const body = `event: timer\ndata: ${
                new Date().toISOString()
              }\n\n\n`;
              controller.enqueue(body);
              time();
            }
          }, 1000);
        })();
      },
      cancel() {
        cancelled = true;
        console.log("Stream cancelled");
      },
    });
    return {
      body: stream.pipeThrough(new TextEncoderStream()),
      init: { headers: { "content-type": "text/event-stream" } },
    };
  }
}

console.log("Server started...");
Http.serve();

// Start Dapr sidecar in local environment:
//    dapr run --app-id sidecar --dapr-http-port 3500 --components-path ./components
// Run the example:
//    dapr --app-id deco-app --app-port 3000 --components-path ./components run -- deno run -A --unstable --watch example_dapr.ts
// Publish message to topic A:
//    dapr publish --publish-app-id sidecar --pubsub pubsub --topic A --data '{"data": "message for topic A"}'
// Publish message to topic B and get Telegrom notification (needs TELEGRAM_TOKEN and TELEGRAM_CHATID exist in the secrets store):
//    dapr publish --publish-app-id sidecar --pubsub pubsub --topic B --data '{"text": "Hello from Deco.Dapr!"}'
// Publish message to topic C to see raw message format:
//    dapr publish --publish-app-id sidecar --pubsub pubsub --topic C --data '{"raw": "raw message for topic C"}'
// Invoke "test" service
//    dapr invoke --app-id deco-app --verb GET --method test
// Send data to the actor
//    curl -X POST "http://localhost:3500/v1.0/actors/TestActor/1/method/testMethod1" -d "{test: 'data'}"

import {
  Actor,
  Bindings,
  Dapr,
  PubSub,
  Secrets,
  Service,
  State,
} from "../../decorators/dapr.decorator.ts";
import { sleep } from "../../utils/utils.ts";

const { TELEGRAM_CHATID, TELEGRAM_TOKEN } = await Secrets.getBulk({
  store: "example-secrets-store",
});
const PUBSUBNAME = "pubsub";

@Dapr.App()
class _ExampleApp {
  @PubSub.subscribeTo({ pubSubName: PUBSUBNAME, topicName: "A" })
  A({ data }: { data: unknown }) {
    console.log("topicA =>", data);
  }

  @PubSub.subscribeTo({ pubSubName: PUBSUBNAME, topicName: "B" })
  B({ data }: { data: Record<string, unknown> }) {
    console.log("topicB =>", data);
    if (data.text && TELEGRAM_CHATID && TELEGRAM_TOKEN) {
      const { text } = data;
      const path =
        `/bot${TELEGRAM_TOKEN}/sendMessage?chat_id=${TELEGRAM_CHATID}&text=${text}`;
      Bindings.invoke({
        bindingName: "telegram",
        operation: "GET",
        metadata: { path },
      });
    }
  }

  @PubSub.subscribeTo({
    pubSubName: PUBSUBNAME,
    topicName: "C",
    metadata: { rawPayload: "true" },
  })
  C(raw: Record<string, unknown>) {
    console.log("topicC =>", raw);
  }

  @Bindings.listenTo()
  tweets({ text }: { text: Record<string, unknown> }) {
    console.log(`incoming tweet => "${text}", publishing into topic A`);
    PubSub.publish({
      pubSubName: PUBSUBNAME,
      topicName: "A",
      data: { text },
    });
  }

  private counter = 0;

  @Service.expose()
  async test({ request }: { request: Request }) {
    console.log(
      `test service called, counter: <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mrow><mo>+</mo><mo>+</mo><mi>t</mi><mi>h</mi><mi>i</mi><mi>s</mi><mi mathvariant="normal">.</mi><mi>c</mi><mi>o</mi><mi>u</mi><mi>n</mi><mi>t</mi><mi>e</mi><mi>r</mi></mrow><mo separator="true">,</mo><mi>d</mi><mi>a</mi><mi>t</mi><mi>a</mi><mo>=</mo><mi mathvariant="normal">&quot;</mi></mrow><annotation encoding="application/x-tex">{++this.counter}, data = &quot;</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord">+</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal">t</span><span class="mord mathnormal">hi</span><span class="mord mathnormal">s</span><span class="mord">.</span><span class="mord mathnormal">co</span><span class="mord mathnormal">u</span><span class="mord mathnormal">n</span><span class="mord mathnormal">t</span><span class="mord mathnormal" style="margin-right:0.02778em;">er</span></span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">d</span><span class="mord mathnormal">a</span><span class="mord mathnormal">t</span><span class="mord mathnormal">a</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord">&quot;</span></span></span></span>{await request
        .text()}"`,
    );
    await sleep(1000);
    return {
      body: `test reply, counter: ${this.counter}`,
    };
  }
}

@Dapr.App()
// deno-lint-ignore no-unused-vars
class TestActor {
  counter = 0;

  @Actor.eventHandler()
  async activate(
    { actorType, actorId }: { actorType: string; actorId: string },
  ) {
    console.log(this);
    console.log(
      `TestActor with actorId="${actorId}" activated, counter reset\nCreating reminder and timer...`,
    );
    this.counter = 0;
    await Actor.createReminder({
      actorType,
      actorId,
      methodName: "testReminder",
      dueTime: "20s",
      period: "0",
    });
    console.log("getReminder =>", await (await Actor.getReminder({actorType, actorId, methodName: "testReminder"})).text());
    await Actor.createTimer({
      actorType,
      actorId,
      methodName: "testTimer",
      dueTime: "5s",
      period: "0s",
    });
  }

  @Actor.eventHandler()
  deactivate({ actorId }: { actorId: string }) {
    console.log(`TestActor with actorId="${actorId}" deactivated`);
  }

  @Actor.method()
  testReminder(
    { actorType, actorId, methodName }: {
      actorType: string;
      actorId: string;
      methodName: string;
    },
  ) {
    console.log(
      `⏱ Actor reminder invoked, actorType="${actorType}", actorId="${actorId}", reminder="${methodName}"`,
    );
  }

  @Actor.method()
  testTimer(
    { actorType, actorId, methodName }: {
      actorType: string;
      actorId: string;
      methodName: string;
    },
  ) {
    console.log(
      `⏰ Actor timer invoked, actorType="${actorType}", actorId="${actorId}", reminder="${methodName}"`,
    );
  }

  @Actor.method()
  async testMethod1(
    { actorType, actorId, methodName, request }: {
      actorType: string;
      actorId: string;
      methodName: string;
      request: Request;
    },
  ) {
    const data = await request.text();
    console.log(
      `actor invoked with data="${data}", actorType="${actorType}", actorId="${actorId}", method="${methodName}", counter=${this.counter}`,
    );
    return `counter: ${++this.counter}`;
  }

  @Actor.method()
  async testMethod2(
    { actorType, actorId, methodName, request }: {
      actorType: string;
      actorId: string;
      methodName: string;
      request: Request;
    },
  ) {
    const data = await request.text();
    console.log(
      `actor invoked with data="${data}", actorType="${actorType}", actorId="${actorId}", method="${methodName}"`,
    );
    if (this.counter < 10) {
      // Invokes itself asynchronously
      Actor.invoke({
        actorType,
        actorId,
        methodName,
        data: `test data from myself, counter=${this.counter}`,
      });
    }
    return `counter: ${++this.counter}`;
  }
}

// Setting and getting state
await State.set({
  storename: "example-state-store",
  data: [{ key: "key1", value: "value1" }, { key: "key3", value: "value3" }],
});
console.log(
  `key1=${
    JSON.stringify(
      await (await State.get({ storename: "example-state-store", key: "key1" }))
        .text(),
    )
  }`,
);
console.log(
  `missing=${
    JSON.stringify(
      await (await State.get({
        storename: "example-state-store",
        key: "missing",
      })).text(),
    )
  }`,
);
console.log(
  `bulk=${
    JSON.stringify(
      await (await State.getBulk({
        storename: "example-state-store",
        data: { keys: ["key1", "missing", "key3"] },
      })).text(),
    )
  }`,
);

console.log("Dapr app started...");
Dapr.start({ appPort: 3000, actorIdleTimeout: "5s" });