( English is not my mother language, please don’t mind my poor English 🙂 )

I have a folder that saves svgs for some technologies’ logo (React, Vue, etc.), and each of the filenames looks like [technology-name].svg (React.svg, Vue.svg, etc.). So I used fs.readdir to read the folder, then return the names as an array like ['React', 'Vue'].

Now I want to extract the names as a union type (‘React’ | ‘Vue’) to get type support, but It seems not possible to do so. The ‘const’ assertion show me an error: “A ‘const’ assertions can only be applied to references to enum members, or string, number, boolean, array, or object literals.”, but the type of SVGNames is string[], it makes me confused.

import { readdir } from 'node:fs/promises'
import { cwd } from 'node:process'

const getSVGNames = async () => {
  const fileNames = await readdir(`${cwd()}/public/svgs`)
  const SVGNames = fileNames.map(fileName => {
    const SVGName = fileName.split('.')[0]
    return SVGName
  })

  return SVGNames as const
}     // ^?const SVGNames: string[]

export {
  getSVGNames
}

Since it didn’t work correctly as I thought, I saved the filename and its path manually. Now it looks like below:

 const iconSet = {
  Astro: "svgs/Astro.svg",
  NodeJS: "svgs/NodeJS.svg",
  React: "svgs/React.svg",
  // ...
  Solid: "svgs/Solid.svg",
  TypeScript: "svgs/TypeScript.svg",
  Vue: "svgs/Vue.svg",
};

When I have new logo to put in, I have to add key-value pair to the iconSet manually, it is so repeating-my-self.

I saw a post from reddit, it said that it doesn’t seems possible to do so.

Could someone help? Highly appreciated!