transform non-default imports and exports using babel

since they are not supported by njs.

polyfill also added

_src/babel-njs/hooks.mjs

@@ -0,0 +1,33 @@
+const commonJSHooksKey =
+  "transform-njs-module/customWrapperPlugin";
+
+export function defineCommonJSHook(file, hook) {
+  let hooks = file.get(commonJSHooksKey);
+  if (!hooks) file.set(commonJSHooksKey, (hooks = []));
+  hooks.push(hook);
+}
+
+function findMap(arr, cb) {
+  if (arr) {
+    for (const el of arr) {
+      const res = cb(el);
+      if (res != null) return res;
+    }
+  }
+}
+
+export function makeInvokers(file){
+  const hooks = file.get(commonJSHooksKey);
+
+  return {
+    getWrapperPayload(...args) {
+      return findMap(hooks, hook => hook.getWrapperPayload?.(...args));
+    },
+    wrapReference(...args) {
+      return findMap(hooks, hook => hook.wrapReference?.(...args));
+    },
+    buildRequireWrapper(...args) {
+      return findMap(hooks, hook => hook.buildRequireWrapper?.(...args));
+    },
+  };
+}

_src/babel-njs/index.mjs

@@ -0,0 +1,88 @@
+import { declare } from "@babel/helper-plugin-utils";
+import {
+  isModule,
+  rewriteModuleStatementsAndPrepareHeader,
+  isSideEffectImport,
+  buildNamespaceInitStatements,
+  ensureStatementsHoisted,
+  wrapInterop,
+  getModuleName,
+} from "@babel/helper-module-transforms";
+
+import { template, types as t } from "@babel/core";
+
+import { makeInvokers } from "./hooks.mjs";
+
+export default declare((api) => {
+  return {
+    name: "transform-njs-module",
+
+    visitor: {
+      Program: {
+        exit(path, state) {
+          if (!isModule(path)) return;
+
+          // Rename the bindings auto-injected into the scope so there is no
+          // risk of conflict between the bindings.
+          path.scope.rename("exports");
+
+          let moduleName = getModuleName(this.file.opts, {});
+          // @ts-expect-error todo(flow->ts): do not reuse variables
+          if (moduleName) moduleName = t.stringLiteral(moduleName);
+
+          const hooks = makeInvokers(this.file);
+
+          const { meta, headers } = rewriteModuleStatementsAndPrepareHeader(
+            path,
+            {
+              exportName: "exports",
+              constantReexports: true,
+              enumerableModuleMeta: true,
+              strict: true,
+              strictMode: true,
+              allowTopLevelThis: true,
+              importInterop: "none",
+              wrapReference: hooks.wrapReference,
+              getWrapperPayload: hooks.getWrapperPayload,
+              esNamespaceOnly: true,
+              filename: this.file.opts.filename,
+            },
+          );
+
+          headers.unshift(...template.statements.ast(`
+            const exports = {};
+            export default exports;
+          `));
+
+          for (const [source, metadata] of meta.source) {
+            let header;
+            if (isSideEffectImport(metadata)) {
+              header = t.importDeclaration([], t.stringLiteral(source));
+            } else {
+              header = t.importDeclaration([t.importDefaultSpecifier(t.identifier(metadata.name))], t.stringLiteral(source));
+            }
+            header.loc = metadata.loc;
+
+            headers.push(header);
+            headers.push(
+              ...buildNamespaceInitStatements(
+                meta,
+                metadata,
+                hooks.wrapReference,
+              ),
+            );
+          }
+
+          ensureStatementsHoisted(headers);
+          path.unshiftContainer("body", headers);
+          path.get("body").forEach(path => {
+            if (headers.indexOf(path.node) === -1) return;
+            if (path.isVariableDeclaration()) {
+              path.scope.registerDeclaration(path);
+            }
+          });
+        },
+      },
+    },
+  };
+});

_src/entrypoints-njs/legacy_index.js

@@ -1,3 +1,4 @@
+import "../lib/njs-polyfill.js";
 import Mark from "markup-js";
 import processingHandlers from "../lib/mirrorListDataProcessing";
 import { TUNASYNC_JSON_PATH } from "../lib/consts";

_src/lib/njs-polyfill.js

@@ -0,0 +1 @@
+import "core-js/modules/es.object.from-entries";

_vite.config.mjs

@@ -182,6 +182,7 @@ export default defineConfig(({ mode }) => ({
                   "babel-preset-njs",
                 ],
                 plugins: [
+                  "./_src/babel-njs/index.mjs",
                 ],
                 configFile: false,
               }),