Vite Plugin

Exported from usewagen/vite.

usewagen

function usewagen(options?: WagenPluginOptions): Plugin

Scans the given directories for parsers, serves them from a virtual module and writes the declaration that teaches TypeScript their names.

vite.config.ts

import { defineConfig } from 'vite'
import { usewagen } from 'usewagen/vite'

export default defineConfig({
  plugins: [usewagen({ dirs: 'src/parsers' })],
})

Options

Option	Type	Default
dirs	string | string[]	'src/parsers'
dts	string | false	'usewagen.d.ts'

dirs is resolved from the Vite root and is walked recursively.

dts is where the declaration file is written. Point it somewhere else when your types live in a folder, or set it to false to declare the names yourself. See Vite Plugin for what the declaration does and how TypeScript is told about it.

What is scanned

A file is read when it ends in .js, .mjs, .ts or .mts and is not a declaration file. Inside it, an export is picked up when it is a const whose name begins with parseAs.

src/parsers/slug.ts

export const parseAsSlug = defineParser<string>({
  parse: raw => (/^[a-z0-9-]+$/.test(raw) ? raw : null),
})

Anything else is left alone, including a parser exported under another name, a let, a default export and a re-export. Commented out code is stripped before the scan, so a parser inside a comment is not registered.

A name a built-in already uses is skipped with a warning, and a name found in two files warns as well, where the file read last wins.

virtual:usewagen/parsers

The module the plugin serves. It exports parsers, a record of everything the scan found, keyed by the name it was exported under.

main.ts

import { createWagen } from 'usewagen'
import { parsers } from 'virtual:usewagen/parsers'

const wagen = createWagen({ parsers })

A scanned file that is added, changed or removed while the dev server runs makes the plugin scan again, rewrite the declaration and reload the page, so a new parser needs no restart.

usewagen/client is the declaration that says this module exists. It ships with the package and is referenced by the generated file, so a project with dts on never adds it by hand.