Use rollup's generatedCode for ES5 compatibility

Author: diskdance

README.MD

@@ -10,9 +10,9 @@ This plugin provides support for integrating Rollup with external packages from
 
 
 ## Usage
-`gadget-def.txt`:
+`.gadgetdefinition`:
 ```
-* codextest [ResourceLoader | package | dependencies=user.options ] | codextest.js | codextest-main.js | codextest-ChangeNameDialog.js
+* my-gadget [ ResourceLoader | package | dependencies=user.options ] | my-gadget.js | my-gadget-main.js | my-gadget-AppComponent.js
 ```
 
 `rollup.config.js`:
@@ -21,20 +21,21 @@ import mwGadget from 'rollup-plugin-mediawiki-gadgets';
 
 export default {
   output:{
-    format: 'cjs', // Or 'iife' for a single bundle
+    // Or 'iife' for a single bundle
+    format: 'cjs',
+
+    // By default the generated code uses arrow functions for smaller code size
+    // Set this if you need ECMAScript 5 compatibility
+    generatedCode: 'es5',
   },
   plugins: [
     mwGadget({
       // Note that the gadget must be ResourceLoader compatible
-      gadgetDef: './gadget-def.txt',
+      gadgetDef: '.gadgetdefinition',
 
       // Additional dependencies to load conditionally using import()
       // It will be transpiled to mw.loader.using calls on the fly
       softDependencies: ['vue', '@wikimedia/codex'],
-
-      // By default the generated code uses arrow functions for smaller code size
-      // Set this to `true` if you need ECMAScript 5 compatibility
-      legacy: false,
     })
   ]
 };

package.json

@@ -1,6 +1,6 @@
 {
   "name": "rollup-plugin-mediawiki-gadget",
-  "version": "1.0.7",
+  "version": "1.1.0",
   "description": "Rollup MediaWiki gadgets with modern goodies",
   "source": "src/index.ts",
   "main": "dist/index.cjs",

src/index.ts

@@ -1,13 +1,11 @@
 import { readFileSync } from 'fs';
-import type { Plugin } from 'rollup';
+import type { NormalizedOutputOptions, Plugin } from 'rollup';
 
 interface MwGadgetConfig {
   /** Path of the gadget definition file. */
   gadgetDef: string,
   /** Additional lazy-load dependencies. */
   softDependencies?: string[],
-  /** Set to `true` if you need ECMAScript 5 compatibility. */
-  legacy?: boolean,
 }
 
 const OPTION_REGEX = /\[(.*?)\]/;
@@ -42,6 +40,7 @@ function getGadgetDependencies(gadgetDefPath: string): string[] {
 function mwGadget(config: MwGadgetConfig): Plugin {
   const dependencies = getGadgetDependencies(config.gadgetDef);
   const softDependencies = config.softDependencies ?? [];
+  let outputOptions: NormalizedOutputOptions;
 
   return {
     name: 'mediawiki-gadget',
@@ -50,13 +49,16 @@ function mwGadget(config: MwGadgetConfig): Plugin {
         return false;
       }
     },
+    async renderStart(receivedOutputOptions) {
+      outputOptions = receivedOutputOptions;
+    },
     renderDynamicImport({ targetModuleId }) {
       if (targetModuleId && softDependencies.includes(targetModuleId)) {
         return {
           left: 'mw.loader.using(',
-          right: config.legacy
-            ? `).then(function(require){return require("${targetModuleId}")})`
-            : `).then(require=>require("${targetModuleId}"))`,
+          right: outputOptions.generatedCode.arrowFunctions
+            ? `).then(require=>require("${targetModuleId}"))`
+            : `).then(function(require){return require("${targetModuleId}")})`,
         };
       }
     },