Converted @rollup/html to a standalone package (out of the original monorepo) and made it ESM-native

test/util/test.d.ts

@@ -0,0 +1,45 @@
+/* eslint-disable import/no-extraneous-dependencies */
+import type { RollupBuild, OutputOptions, OutputChunk, OutputAsset } from 'rollup';
+import type { Assertions } from 'ava';
+
+interface GetCode {
+  (bundle: RollupBuild, outputOptions?: OutputOptions | null, allFiles?: false): Promise<string>;
+  (bundle: RollupBuild, outputOptions: OutputOptions | null | undefined, allFiles: true): Promise<
+    Array<{
+      code: OutputChunk['code'] | undefined;
+      fileName: OutputChunk['fileName'] | OutputAsset['fileName'];
+      source: OutputAsset['source'] | undefined;
+    }>
+  >;
+}
+
+export const getCode: GetCode;
+
+export function getFiles(
+  bundle: RollupBuild,
+  outputOptions?: OutputOptions
+): Promise<
+  {
+    fileName: string;
+    content: any;
+  }[]
+>;
+
+export function evaluateBundle(bundle: RollupBuild): Promise<Pick<NodeModule, 'exports'>>;
+
+export function getImports(bundle: RollupBuild): Promise<string[]>;
+
+export function getResolvedModules(bundle: RollupBuild): Promise<Record<string, string>>;
+
+export function onwarn(warning: string | any): void;
+
+export function testBundle(
+  t: Assertions,
+  bundle: RollupBuild,
+  options: { inject: Record<string, any>; options: Record<string, any> }
+): Promise<{
+  code: string;
+  error?: any;
+  result?: any;
+  module: Pick<NodeModule, 'exports'>;
+}>;

test/util/test.js

@@ -0,0 +1,95 @@
+import path from "node:path";
+import process from "node:process";
+
+/**
+ * @param {import('rollup').RollupBuild} bundle
+ * @param {import('rollup').OutputOptions} [outputOptions]
+ */
+export const getCode = async (bundle, outputOptions, allFiles = false) => {
+  const { output } = await bundle.generate(outputOptions || { format: 'cjs', exports: 'auto' });
+
+  if (allFiles) {
+    return output.map(({ code, fileName, source, map }) => {
+      return {
+        code,
+        fileName,
+        source,
+        map
+      };
+    });
+  }
+  const [{ code }] = output;
+  return code;
+};
+
+/**
+ * @param {import('rollup').RollupBuild} bundle
+ * @param {import('rollup').OutputOptions} [outputOptions]
+ */
+export const getFiles = async (bundle, outputOptions) => {
+  if (!outputOptions.dir && !outputOptions.file)
+    throw new Error('You must specify "output.file" or "output.dir" for the build.');
+
+  const { output } = await bundle.generate(outputOptions || { format: 'cjs', exports: 'auto' });
+
+  return output.map(({ code, fileName, source }) => {
+    const absPath = path.resolve(outputOptions.dir || path.dirname(outputOptions.file), fileName);
+    return {
+      fileName: path.relative(process.cwd(), absPath).split(path.sep).join('/'),
+      content: code || source
+    };
+  });
+};
+
+export const getImports = async (bundle) => {
+  if (bundle.imports) {
+    return bundle.imports;
+  }
+  const { output } = await bundle.generate({ format: 'es' });
+  const [{ imports }] = output;
+  return imports;
+};
+
+export const getResolvedModules = async (bundle) => {
+  const {
+    output: [{ modules }]
+  } = await bundle.generate({ format: 'es' });
+  return modules;
+};
+
+// eslint-disable-next-line no-console
+export const onwarn = (warning) => console.warn(warning.toString());
+
+/**
+ * @param {import('ava').Assertions} t
+ * @param {import('rollup').RollupBuild} bundle
+ * @param {object} args
+ */
+export const testBundle = async (t, bundle, { inject = {}, options = {} } = {}) => {
+  const { output } = await bundle.generate({ format: 'cjs', exports: 'auto', ...options });
+  const [{ code }] = output;
+  const module = { exports: {} };
+  // as of 1/2/2020 Github Actions + Windows has changed in a way that we must now escape backslashes
+  const cwd = process.cwd().replace(/\\/g, '\\\\');
+  const params = ['module', 'exports', 'require', 't', ...Object.keys(inject)].concat(
+    `process.chdir('${cwd}'); let result;\n\n${code}\n\nreturn result;`
+  );
+
+  // eslint-disable-next-line no-new-func
+  const func = new Function(...params);
+  let error;
+  let result;
+
+  try {
+    result = func(...[module, module.exports, require, t, ...Object.values(inject)]);
+  } catch (e) {
+    error = e;
+  }
+
+  return { code, error, module, result };
+};
+
+export const evaluateBundle = async (bundle) => {
+  const { module } = await testBundle(null, bundle);
+  return module.exports;
+};