Anthony Fu @

TwoSlash with Shiki

Dec 12, 2023 · 2min

Here is an example of using TwoSlash with Shiki:

var console: Consoleconsole.Console.log( any[]): void
[MDN Reference](
((1 + 2 + 3 + 4).to
  • toExponential
  • toFixed
  • toLocaleString
  • toPrecision
  • toString
Number.toFixed(fractionDigits?: number | undefined): string
Returns a string representing a number in fixed-point notation.
@paramfractionDigits Number of digits after the decimal point. Must be in the range 0 - 20, inclusive.
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 readonly
<Todo> = {
title: string
: 'Delete inactive users',
} const todo: Readonly<Todo>todo.title = 'Hello'
Cannot assign to 'title' because it is a read-only property.

Try hovering on each token to see the type information. Shiki runs oniguruma to give syntax highlighting, and TwoSlash runs typescript to give type information. Both are quite heavy libraries, but this is done ahead of time on building, it means that what you see here is completely static pure HTML and CSS!

The Shiki integration allows you to provide custom renderer of how the HTML been generated based on AST. This allows us to have dual themes support, and also the syntax highlighting for the type information.

Check @shikijs/twoslash and commit for the integration on, for more information :)

The input code
```ts twoslash
// @errors: 2540
console.log((1 + 2 + 3 + 4).toFixed(2))
//                            ^|

interface Todo {
  title: string

const todo: Readonly<Todo> = {
  title: 'Delete inactive users',
//  ^?

todo.title = 'Hello'
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