Some packages may need some extra options for ncc support in order to better work with the static analysis.
See [package-support.md](package-support.md) for some common packages and their usage with ncc.
### Programmatically From Node.js
```js
require('@vercel/ncc')('/path/to/input', {
// provide a custom cache path or disable caching
cache: "./custom/cache/path" | false,
// externals to leave as requires of the build
externals: ["externalpackage"],
// directory outside of which never to emit assets
filterAssetBase: process.cwd(), // default
minify: false, // default
sourceMap: false, // default
sourceMapBasePrefix: '../', // default treats sources as output-relative
// when outputting a sourcemap, automatically include
// source-map-support in the output file (increases output by 32kB).
sourceMapRegister: true, // default
watch: false, // default
license: '', // default does not generate a license file
v8cache: false, // default
quiet: false, // default
debugLog: false // default
}).then(({ code, map, assets }) => {
console.log(code);
// Assets is an object of asset file names to { source, permissions, symlinks }
// expected relative to the output code (if any)
})
```
When `watch: true` is set, the build object is not a promise, but has the following signature:
```js
{
// handler re-run on each build completion
// watch errors are reported on "err"
handler (({ err, code, map, assets }) => { ... })
// handler re-run on each rebuild start
rebuild (() => {})
// close the watcher
void close ();
}
```
## Caveats
- Files / assets are relocated based on a [static evaluator](https://github.com/zeit/webpack-asset-relocator-loader#how-it-works). Dynamic non-statically analyzable asset loads may not work out correctly
