Twoslash Support

Twoslash provides an inline type hove inside the code block.

Basic usage

You can enable twoslash to your code blocks by adding a twoslash metadata:

Markdown

```ts twoslash
// @errors: 2540
interface Todo {
  title: string
}
 
const todo: Readonly<Todo> = {
  title: 'Delete inactive users'.toUpperCase()
  //  ^?
}
 
todo.title = 'Hello'
 
Number.parseInt('123', 10)
//      ^|
```

Renders:

interface Todo {
  Todo.title: stringtitle: string
}
 
const const todo: Readonly<Todo>todo: type Readonly<T> = { readonly [P in keyof T]: T[P]; }Make all properties in T readonlyReadonly<Todo> = {
  
title: stringtitle: 'Delete inactive users'.String.toUpperCase(): stringConverts all the alphabetic characters in a string to uppercase.toUpperCase()
}
 
const todo: Readonly<Todo>todo.title = 'Hello'Cannot assign to 'title' because it is a read-only property.
 
var Number: NumberConstructorAn object that represents a number of any kind. All JavaScript numbers are 64-bit floating-point numbers.Number.pparseFloat
parseInt
prototypeNumberConstructor.parseInt(string: string, radix?: number): numberConverts A string to an integer.
@paramstring A string to convert into a number.@paramradix A value between 2 and 36 that specifies the base of the number in `string`.
If this argument is not supplied, strings with a prefix of '0x' are considered hexadecimal.
All other strings are considered decimal.arseInt('123', 10)

Custom log message

You can add log message to your code by adding:

@log: <message> Custom log message
@error: <message> Custom error message
@warn: <message> Custom warn message
@annotate: <message> Custom annotate message

const const a: 1a = 1Custom log message
const const b: 1b = 1Custom error message
const const c: 1c = 1Custom warning message
 Custom annotation message