main.ts

#!/usr/bin/env deno run --allow-env --allow-run

import { HTTPStatus } from '@oneday/http-status'
import stream from 'node:stream'
import { setTimeout as sleep } from 'node:timers/promises'
import process from 'node:process'
import { Buffer } from 'node:buffer'
import { pipeline } from 'node:stream/promises'

/**
 * Adds x and y.
 *
 * # Examples
 *
 * ```ts
 * import { assertEquals } from "jsr:@std/assert/equals";
 *
 * const sum = add(1, 2);
 * assertEquals(sum, 3);
 * ```
 */
export function add(x: number, y: number): number {
  return x + y
}

console.log(add(1, 2))

console.log(HTTPStatus.OK)

console.info('\nPrepare\n---\n')
async function* generate() {
  let index = 0

  while (index < 4) {
    await sleep(50)
    index++
    yield { name: 'hello' }
  }
}

// Simple
// Test simple
// stream.Readable.from(generate()).on('data', (chunk) => console.log(chunk))

console.info('\nReadable\n---\n')
for await (const item of stream.Readable.from(generate())) {
  console.log('readable:', item)
}

// Pipeline
console.info('\nPipeline\n---\n')

await pipeline(
  generate(),
  async function* (source) {
    for await (const chunk of source) {
      yield chunk.name.toString().toUpperCase()
    }
  },
  async (source) => {
    for await (const chunk of source) {
      console.log('pipeline:', chunk)
    }
  },
)

// Transform
console.info('\nTransform\n---\n')

const upper = new stream.Transform({
  transform: function (data, _enc, cb) {
    this.push(Buffer.from(JSON.stringify({ name: data.name.toUpperCase() })))

    cb()
  },
  objectMode: true,
})

stream.Readable.from(generate())
  .pipe(upper)
  .pipe(process.stdout)

// Pattern iterator async
console.info('\nTPattern iterator\n---\n')
function range(start: number, end: number, step = 1) {
  let started = start

  return {
    [Symbol.iterator]() {
      return this
    },
    async next() {
      if (started < end) {
        await sleep(10)
        started = started + step

        return { value: started, done: false }
      }
      return { done: true, value: end }
    },
  }
}

const countdown = range(0, 4, 2)

let result = await countdown.next()

while (!result.done) {
  console.log('pattern iterator async:', result.value)

  result = await countdown.next()
}

await sleep(1500)

console.log('')
console.info('bye')