two slash test

Table of contents

twoslash Tests

ts
// ts twoslash
console.log(str);
            
const str: "hello world"Try

ts
// ts twoslash
console.log(str);
            
const str: "hello world"Try

ts
// ts
const str = "hello world";
console.log(str);

ts
// ts
const str = "hello world";
console.log(str);

twoslash annotation

ts
function compact(arr) {
  if (orr.length > 10) {
Cannot find name 'orr'.2304Cannot find name 'orr'.
    return arr.trim(0, 10);
  }
  return arr;
}Try

ts
function compact(arr) {
  if (orr.length > 10) {
Cannot find name 'orr'.2304Cannot find name 'orr'.
    return arr.trim(0, 10);
  }
  return arr;
}Try

twoslash completions

ts
const arr = [1, 2];
 
function sum(...arr: number[]) {
  return arr.s
              
shift
slice
some
sort
splice
}Try

ts
const arr = [1, 2];
 
function sum(...arr: number[]) {
  return arr.s
              
shift
slice
some
sort
splice
}Try

twoslash error

ts
const a = "123";
a = 132;
Cannot assign to 'a' because it is a constant.2588Cannot assign to 'a' because it is a constant.Try

ts
const a = "123";
a = 132;
Cannot assign to 'a' because it is a constant.2588Cannot assign to 'a' because it is a constant.Try

twoslash filecut

ts
import { helloWorld } from "./a";
console.log(helloWorld);Try

ts
import { helloWorld } from "./a";
console.log(helloWorld);Try

twoslash json

ts
// @filename: app.json
{ "version": "23.2.3" }
 
// @filename: index.ts
import appSettings from "./app.json"
appSettings.version
              
(property) "version": stringTry

ts
// @filename: app.json
{ "version": "23.2.3" }
 
// @filename: index.ts
import appSettings from "./app.json"
appSettings.version
              
(property) "version": stringTry

twoslash log

ts
console.log("Hello world");
Hello world
 
console.warn("Ola Mundo");
Old  Mundo
 
console.error("Neih hou");
Neih houTry

ts
console.log("Hello world");
Hello world
 
console.warn("Ola Mundo");
Old  Mundo
 
console.error("Neih hou");
Neih houTry

twoslash twofiles

ts
// @filename: node_modules/@types/mylib/index.d.ts
export function doit(): string;
 
// @filename: index.ts
import { doit } from "mylib";
console.log(doit);Try

ts
// @filename: node_modules/@types/mylib/index.d.ts
export function doit(): string;
 
// @filename: index.ts
import { doit } from "mylib";
console.log(doit);Try

twoslash

ts
function createLabel<T extends number | string>(idOrName: T): NameOrId<T> {
  throw "unimplemented";
}
 
let a = createLabel("typescript");
   
let a: NameLabel
 
let b = createLabel(2.8);
   
let b: IdLabel
 
let c = createLabel(Math.random() ? "hello" : 42);
let c: NameLabel | IdLabelTry

ts
function createLabel<T extends number | string>(idOrName: T): NameOrId<T> {
  throw "unimplemented";
}
 
let a = createLabel("typescript");
   
let a: NameLabel
 
let b = createLabel(2.8);
   
let b: IdLabel
 
let c = createLabel(Math.random() ? "hello" : 42);
let c: NameLabel | IdLabelTry