Node.js Development in 2020: trends and techniques

Transcript

1. Node.js Development in 2020: trends and techniques by Nikita Galkin

   Nov 8, 2019

2. What anniversary is today?

3. None
4. None

5. Why Node.js won the market? 1. Everybody knows JavaScript 2.

   Everybody loves Open Source 3. Google pay for V8 4. Performance boost every release 5. There is a release schedule
6. None

7. nvm install 12.13.0 nvm alias default 12.13.0 nvm reinstall-packages 10.16.3

   Migrate your local version easy with nvm:

8. Node.js v12 Breaking changes

9. None
10. None

11. Breaking change at Event Loop for Timers and Microtasks

12. setTimeout(() => console.log('timeout1')); setTimeout(() => { console.log('timeout2'); Promise.resolve().then(() => console.log('promise

    resolve') ); }); setTimeout(() => console.log('timeout3')); setTimeout(() => console.log('timeout4'));
13. None

14. 6.8 ➜ 7.7

15. ➜ ~ nvm use v10 Now using node v10.16.3 (npm

    v6.9.0) ➜ ~ node --print process.versions.v8 6.8.275.32-node.54 ➜ ~ nvm use v12 Now using node v12.13.0 (npm v6.12.0) ➜ ~ node --print process.versions.v8 7.7.299.13-node.12 6.8 ➜ 7.7

16. const array = []; for (let i = 1; i

    < 10000; i++) array.push(i); console.time('assign'); const assign = array.reduce( (acc, curr) => Object.assign(acc, {[curr]: curr}), {}); console.timeEnd('assign'); console.time('spread'); const spread = array.reduce( (acc, curr) => ({...acc, [curr]: curr}), {}); console.timeEnd('spread');
17. None

18. 1. Faster JavaScript parsing 2. Faster async functions and promises

    3. Zero-cost async stack traces

19. const { promisify } = require('util'); const wait = promisify(setTimeout);

    async function testAsyncStacktrace() { await wait(10); await willDie(); return 42; } async function willDie() { await Promise.resolve(); throw new Error('#Feelsbadman'); } testAsyncStacktrace() .catch(error => console.log(error.stack));
20. None

21. By default stack-trace is 10 On CLI level ➜ ~

    node async-stack-trace.js \ --stack-trace-limit=1000 On code level Error.stackTraceLimit = Infinity; More

22. Node.js features

23. Node.js v12 disappointments 1. ECMAScript Modules support is not stable.

    Again. 2. Most native modules are callback based. Only fs and dns modules have promises.

24. JavaScript designed for browser where a failure affects only one

    tab, only one user. But at Node.js failing affect everything...

25. Worker Threads are no longer experimental!

26. None

27. New http parser llhttp based on llparse

28. 1. You use it! 2. For your own parser 3.

    TypeScript Why learn how it works?

29. native Promises

30. 1. Faster JavaScript parsing 2. Faster async functions and promises

    3. Zero-cost async stack traces

31. What need to know: 1. promisify from util 2. once

    from events 3. Reading streams asynchronously

32. function wait(timeout) { return new Promise(resolve => { setTimeout(resolve, timeout));

    }); } // VS const util = require('util'); const wait = util.promisify(setTimeout);

33. const { EventEmitter } = require('events'); const emitter = new

    EventEmitter(); async function getPromise() { return new Promise(resolve => { emitter.once('eventName', resolve); }) }

34. const { EventEmitter } = require('events'); const { once }

    = require('events'); const emitter = new EventEmitter(); async function getPromise() { return once( emitter, 'eventName'); }

35. const { EventEmitter } = require('events'); const emitter = new

    EventEmitter(); async function getPromise() { return new Promise(resolve => { emitter.once('eventName', resolve); }) }

36. async function main(filePath) { const readStream = fs.createReadStream(filePath); for await

    (const chunk of readStream) { console.log('>>> '+chunk); } console.log('### DONE ###'); }

37. What need to use: 1. Promise.all/Promise.race 2. p-limit 3. multipleResolves

    from process

38. Next big thing is QUIC/HTTP3

39. None

40. Node.js news

41. 1. Node.js Foundation and JS Foundation Merge to Form OpenJS

    Foundation 2. Node.js certification 3. Nodejs.dev arrived
42. None

43. 1. Boolean 2. Null 3. Undefined 4. Number 5. String

    6. Symbol 7. Object Data types in JavaScript.

44. 1. Boolean 2. Null 3. Undefined 4. Number 5. String

    6. Symbol 7. Object 8. BigInt Data types in JavaScript.

45. Not only Node.js news

46. 1. TC39 new proposals 2. GraphQL is not hype and

    has foundation. 3. Nestjs is the most promising framework

47. TypeScript 3.7

48. None

49. HAPPY NODE.JS DEVELOPMENT! You can find me on Twitter as

    @galk_in Slides are available at speakerdeck.com/galkin or at my site galk.in