Using Typescript at scale
Typescript
for Asgardians
(of the Galaxy)
VOL.2
Charlie L
Sr Software Engineer at Humu
@charliesbot
Co-host @Los Full Stackers podcast
What's new with Typescript?
The biggest news in 2018
- Typescript 3.4!
- Incremental flag
- TSLint is deprecated. ESLint is the way to go
- TS has a Babel plugin
- Node creator is working in Deno, which uses TS
- Vue is moving from Flow to Typescript 🎉
- Apollo GraphQL just provides TS definitions
OUTDATED
The biggest news in 2020
- Typescript 4.1!
- Template Literal Types
- Short-Circuiting Assignment Operators
- Svelte and Vue 3 with full TS support 🎉
- Deno reached v1.0 (runtime from the creator of NodeJS)
- TS is the fourth most used language in Github 🤯
The fight is over. Really.
So... what is TypeScript?
TS is a superset of JS
JS
TS
Why you should TS too!
- Types improve code clarity
- Refactor becomes a breeze
- Tons of companies are betting in TS: Asana, Lyft, Atlassian, Microsoft (ofc), Humu, AirBnB, Google, and so on
- If you hate to see undefined is not a function, you'll love TS
This is not another intro to TS
Our lightning journey
- Type Literals
- Control flow
- Generics
let aString = "I'm a string";
let aNumber = 1;
let aBoolean = true;// string
// number
// booleanconst aString = "I'm a string";
const aNumber = 1;
const aBoolean = true;// "I'm a string"
// 1
// trueType literals
It's a type definition whose type is any value you'd simply type out exactly
Unions
They describe a value that can be one of several types (|)
type Animal = 'cat' | 'dog' | 'fish';Control flow
Live coding
(Why not?)
Generics
They help us to create a component that can work over a variety of types rather than a single one.
// How can we reuse this function for every single type
// that you could imagine? 🤔
function identity(x) {
return x;
}
Live coding
Agaaaaain
Let's wrap this up
There's more (a lot more)
- Mapped types
- Type guards
- Utilities (Pick, Exclude, ReturnType)
- Libraries already typed!
Advanced TS techniques help you to
- Enforce guidelines
- Be confident about your code
- Document what you do on the way
- Speed up your PRs!
- Refactor
Charlie L
Twitter: @charliesbot
Podcast: Los Full Stackers
Typescript for Asgardians
By Carlos Lopez
