What is a simple way to have TypeScript recognize JSX (especially in VS Code) without having React as a dependency? If we have to use a custom JSX namespace and a custom renderer, then what is the expected shape of the contents of that namespace and the renderer?

As far as I know, JSX is just syntactic sugar that is transformed into function calls (e.g., React.createElement), so there should be a way to specify that a different function should be used for transforming the JSX.

Looking at the release docs for TypeScript 2.8, I see there are sections titled "Per-file JSX factories" and "Locally scoped JSX namespaces", but I don't see these sections in the official current TypeScript docs. Have these features been deprecated?

What is a simple way to have TypeScript recognize JSX (especially in VS Code) without having React as a dependency? If we have to use a custom JSX namespace and a custom renderer, then what is the expected shape of the contents of that namespace and the renderer?

As far as I know, JSX is just syntactic sugar that is transformed into function calls (e.g., React.createElement), so there should be a way to specify that a different function should be used for transforming the JSX.

Looking at the release docs for TypeScript 2.8, I see there are sections titled "Per-file JSX factories" and "Locally scoped JSX namespaces", but I don't see these sections in the official current TypeScript docs. Have these features been deprecated?

• javascript
• reactjs
• typescript
• visual-studio-code

• Possible duplicate of can i use jsx without React to inline html in script? – Bourbia Brahim Commented Jan 11, 2019 at 10:12
• 1 @Berr'ita: This is not a duplicate. I specifically indicated out I want to use TypeScript in VSCode (to retain the intellisense features). The other question talks about babel plugins and third-party packages, which I don't want – prmph Commented Jan 11, 2019 at 10:43

2 Answers 2

jsx and jsxFactory piler options are responsible for that.

TypeScript expects a function defined in jsxFactory to exist in module scope. Usually this requires to import React because jsxFactory defaults to React.createElement.

If the piler is configured with:

...
"jsx": "react",
"jsxFactory": "h",
...

Then h function should exist. JSX-related types should be defined to make type checks work properly:

declare namespace JSX {
  interface Element {}
  interface ElementClass {
    render(): any;
  }
  interface IntrinsicElements {
    div: any;
    // ...
  }
}

const h = (Comp: any): any => console.log(`creating ${Comp} element`);

<div/>;

class FooComponent {
  render = () => null;
}

<FooComponent/>;

The Typescript piler has flags that allow you to specify how TSX/JSX is handled.

Specifically, you have to specify "--jsx=React" and "--jsxFactory=someModule.yourJsxFactory", and in your tsx files, you supply your custom factory by importing "someModule", from which "yourJsxFactory" should be exported.

Read more about it at
Typescript (Compiler Options)
and
Typescript (JSX)