Not to remove unused import module ?

[zD98]

TypeScript Version: 2.4.1

Code

// tsconfig.json
{
...
"jsx": "preserve",
...
}

// my preact Component
import {h, Component} from 'preact'
class C extends Component<any, any> {
    render(){
    // ...
    }
}

// after compiled
import { Component } from 'preact'

So it will throw an error, such as "h is not defined"

Expected behavior:

// after compiled
import {h, Component } from 'preact'

Actual behavior:

// after compiled
import {Component} from 'preact' 

Related:

[zD98]

Now I have to add a hard code.

import {h as PreactH , Component} from 'preact'
const h = PreactH

[mhegazy]

Assuming you set --jsxFactory h, we should always preserve this import, and make sure h is defined in the output if you ever use a JSX element in this file.

[zD98]

Mohamed Hegazy (@mhegazy) thanks for the quick reply!
--jsxFactory h is ok in a pure TS + Preact project. However, my project has React and Preact frameworks.

[mhegazy]

I do not think we can keep both.. the compiler has no way of knowing which one is used otherwise.

[mhegazy]

I was wrong about my original analysis. h is preserved if it is in the --jsxFactory. so this is not a bug. having both React.createElement and h in the same project is tracked by #15386 and #18131

[typescript-bot]

Automatically closing this issue for housekeeping purposes. The issue labels indicate that it is unactionable at the moment or has already been addressed.