Generate returns a promise

https://github.com/rollup/rollup/blob/master/src/rollup/index.js#L157-L188

"map" will be null if GenerateOptions.sourceMap is false

types/rollup/index.d.ts

@@ -84,7 +84,7 @@ export interface WriteOptions extends BundleOptions {
 
 export interface Bundle {
 	/** Generate bundled code as an object */
-	generate(options: GenerateOptions): { code: string, map: SourceMap }
+	generate(options: GenerateOptions): Promise<{ code: string, map: SourceMap | null }>
 	/** writes the file (and accompanying sourcemap file, if appropriate) to the file system. */
 	write(options: WriteOptions): Promise<void>
 }

types/rollup/rollup-tests.ts

@@ -29,12 +29,14 @@ async function main() {
         plugins: plugin
     })
 
-    const result = bundle.generate({
+    const { code, map } = await bundle.generate({
         format: 'cjs',
         indent: false,
         sourcemap: true,
     })
 
+    console.log(code, map)
+
     cache = bundle
 
     await bundle.write({