test: added testing via a browser (puppeteer)

test/util/code-output.ts

@@ -0,0 +1,26 @@
+import type {RollupBuild, OutputOptions, OutputAsset, OutputChunk, SourceMap} from "rollup";
+
+export interface TestOutput{
+  code: string,
+  fileName: string,
+  source: any,
+  map: any
+}
+
+export const getCode = async (bundle: RollupBuild, outputOptions: OutputOptions): Promise<TestOutput[]> => {
+  const { output } = await bundle.generate(outputOptions || { format: 'cjs', exports: 'auto' });
+
+  return output.sort((a,b)=> {
+    if(a.fileName === b.fileName && (<OutputAsset>a).source !== (<OutputAsset>b).source){ return (<OutputAsset>a).source<(<OutputAsset>b).source?-1:1}
+    return a.fileName < b.fileName ? -1 : (a.fileName > b.fileName? 1 : 0);
+  }).map(chunk=> {
+    const { code, map } = (<OutputChunk>chunk);
+    const { fileName, source } = (<OutputAsset>chunk);
+    return {
+      code,
+      fileName,
+      source,
+      map
+    };
+  });
+};