A way to extend Deno with plugins.
Like Bun Plugins
Deno plugins is able to modify the import(require) logic, like:
- Handle import module load (for example, matching
/\.(yaml|yml)$/ to implement a custom yaml file loader)
- Handle import resolutions
- Register virtual modules (like register
#db and export database connection)
- Purge Module Cache (allowing customized hmr)
deno plugins might be under a permission flag to prevent abuse.
Example Use cases
interface ResolvedModule {
href: URL, // module url, like `npm:zod`, `file:///home/user/loader/tree.ts`
}
interface Module {
exports: any, // module exports
type: "module" | "commonjs" // module type
}
interface OnLoadOptions {
specifier: string, // import specifier, like "`./tree.ts`"
attributes: object, // import attributes, like `{ with: { type: "yaml" }}`
origin: URL, // which module tries import this like `file:///home/user/loader/mod.ts`
next(resolved: ResolvedModule): Promise<Module> //
}For example, implementing YAML loader:
// function
Deno.plugin(async (loader) => {
const { load } = await import("js-yaml");
loader.onLoad({ match: /\.(yaml|yml)$/ }, async (path, _options: OnLoadOptions) {
return {
exports: load(await Deno.readTextFile(path)),
type: "module"
}
})
})
// object
Deno.plugin({
name: 'yaml-loader',
async setup(loader) {
const { load } = await import("js-yaml");
loader.onLoad({ match: /\.(yaml|yml)$/ }, async (module: ResolvedModule, _options: OnLoadOptions) {
const { path } = module
return {
exports: load(await Deno.readTextFile(path)),
type: "module"
}
})
}
})And virtual module (override could existing module):
Deno.plugin(async (loader) => {
const db = drizzle(...)
const mod = await loader.module('#db', (attributes: object, next: (attributes: object) => Promise<Module>) => { // next for default resolution
return {
exports: db,
type: "module"
}
})
})
A way to extend Deno with plugins.
Like Bun Plugins
Deno plugins is able to modify the
import(require) logic, like:/\.(yaml|yml)$/to implement a custom yaml file loader)#dband export database connection)deno plugins might be under a permission flag to prevent abuse.
Example Use cases
For example, implementing YAML loader:
And virtual module (override could existing module):