Install
rollup-plugin-dts
This is a plugin that lets you roll-up your .d.ts definition files.
Usage
Install the package from npm:
$ npm install --save-dev rollup-plugin-dts
Add it to your rollup.config.js:
import dts from "rollup-plugin-dts";
const config = [
// …
{
input: "./my-input/index.d.ts",
output: [{ file: "dist/my-library.d.ts", format: "es" }],
plugins: [dts()],
},
];
export default config;
And then instruct typescript where to find your definitions inside your package.json:
"types": "dist/my-library.d.ts",
NOTE that the plugin will automatically mark any external library
(@types for example) as external, so those will be excluded from bundling.
What to expect
While this plugin is fairly complete, it does not support all imaginable use-cases.
In particular, the plugin works best with already existing .d.ts files generated
by the typescript compiler from idiomatic code.
Working with .ts(x) or even .js(x) (when setting allowJs: true) does work,
but is not recommended.
The plugin does its own import resolution through the typescript compiler, and
usage together with other resolution plugins, such as node-resolve can lead
to errors and is not recommended.
All external dependencies from node_modules are automatically excluded from
bundling. This can be overridden using the respectExternal setting, but it is
generally not recommended. While rollup of external @types generally works,
it is not recommended.
Why?
Well, ideally TypeScript should just do all this itself, and it even has a
proposal to do that.
But there hasn’t been any progress in ~3 years.
Some projects, like rollup itself
go the route of completely separating their public interfaces in a separate file.
Alternatives
See
some
discussions
about some of these projects and their tradeoffs.
How does it work
License
The code is licensed under the copyleft LGPL-3.0. I have no intention to
license this under any non-copyleft license.
