TypeScript = types + ECMAScript

Why JavsScript is bad?

Questions for developer of the module

• What arguments are important
• What types are valid
• What options are valid
• What settings are optional

Questions for user of the module

• Is it save to add one more argument
• Can i remove argument
• What if I return something else

TypeScript saves your live

ES2015 + Types

Types

• Boolean
• Number
• String
• Symbol
• Array
• Tuple
• Void
• Any
• Enum
• Interface

Types

var a: number = 3;

var b: number[] = [1,2,3];

var a: number = <number>b;

function (a?: number, isTrue: boolean = false) { ... }

function (a?: number|string, isTrue: boolean = false) { ... }

Types

var a: any = {};

any is a lie)))

Types

ES2015 transpiler

Classes

• private, protected, public
• abstract
• implements, extends

Generics

namespace

namespace

Future

• Mixins
• Decorators

Demo

Libs

JQuery

Webix

window

console

definition files

http://definitelytyped.org/tsd/

lib.d.ts

new Date

How can I start working with ts

WebStorm

VS + NuGet

VS Code

Compile options

http://www.typescriptlang.org/docs/handbook/tsconfig.json.html

Flags

http://www.typescriptlang.org/docs/handbook/compiler-options.html

Experience...

Performance

ES2015 vs ES5

https://kpdecker.github.io/six-speed/

Modules

Rules

• local scope
• importing
• exporting
• export by reference
• accessing by path

Local scope

var a = 2;

(function(){
    var a = 2;

    return {
        getName: function(){
            return "vlad";
        }
    }
})()

Importing

import defaultMember from "module-name";
import * as name from "module-name";
import { member } from "module-name";
import { member as alias } from "module-name";
import { member1 , member2 } from "module-name";
import { member1 , member2 as alias2 , [...] } from "module-name";
import defaultMember, { member [ , [...] ] } from "module-name";
import defaultMember, * as name from "module-name";
import "module-name";

Exporting

export { name1, name2, …, nameN };
export { variable1 as name1, variable2 as name2, …, nameN };
export let name1, name2, …, nameN; 
export let name1 = …, name2 = …, …, nameN; 
export default expression;
export default function (…) { … }
export default function name1(…) { … } 
export { name1 as default, … };

Exporting

export function a(){}

export class a {  }

export let a = 2;

let a = 3;

export a;

let a = 3;

export { a };

let a = 3;

export { a as num };

export default let a = 5;

Importing

import a from "";

What is in "a"?

export default let a = 6

import b from "";

b.a === 6;

import * as b from "";

b.a === 6;

import { a, num as b } from ""

export let a;

export let function num(){}

by reference

import {a} from "";

a = 2

export let a = 4; 

import {a} from "";

a === 2

Loading

it's ES2015, baby

module tag + HTTP2

AMD

CommonJS

UMD

ES2015

My Solution + commonjs

(fucntion (require, exports) {

       //code

})( getRequire(path), getExports(path))

Questions?