fix(toolbox): resolve Vite 8 build warnings in conformance and workbench

CHANGELOG.md

@@ -70,6 +70,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 * Prevented the FDC3 for Web reference implementation from sending channel-changed events to applications that have not registered a matching listener. ([#1806](https://github.com/finos/FDC3/issues/1806))
 * Fixed an issue in conformance test AOpensBWithWrongContext, which was not correctly waiting for the timeout and was sending close messages outside of the execution of the test. Also added logging of test starts and finishes to aid debugging. ([#1933](https://github.com/finos/FDC3/pull/1933))
 * Fixed the `BasicJC1` conformance test to skip user channel membership checks when `getInfo().optionalFeatures.UserChannelMembershipAPIs` is not advertised, while still validating `joinUserChannel`, `getCurrentChannel`, and `leaveCurrentChannel` when the feature is enabled. ([#1777](https://github.com/finos/FDC3/issues/1777))
+* Fixed all Vite 8 build warnings in `fdc3-conformance` and the `configLoader: 'native'` compatibility warning in `fdc3-workbench`: replaced `__dirname` with `import.meta.dirname`, swapped `@rollup/plugin-inject` for Rolldown's built-in `transform.inject`, made the `fix-source-map-support-global` plugin emit a sourcemap, targeted CSS injection at the `fdc3-compliance` entry, and marked `fdc3-workbench` as an ES module. ([#2115](https://github.com/finos/FDC3/issues/2115))
 * Fixed intermittent failures in the `fdc3.destructuredMethods` conformance tests caused by mock apps not yet being ready when opened, and by too short a timeout when awaiting their close confirmation. ([#2114](https://github.com/finos/FDC3/issues/2114))
 
 ## [npm v2.2.3] - 2026-04-15

toolbox/fdc3-conformance/package.json

@@ -27,7 +27,6 @@
     "util": "^0.12.5"
   },
   "devDependencies": {
-    "@rollup/plugin-inject": "^5.0.5",
     "@types/chai": "^5.2.3",
     "@types/mocha": "^10.0.10",
     "http-server": "^14.1.1",

toolbox/fdc3-conformance/vite.config.ts

@@ -1,19 +1,37 @@
 import path from 'path';
-import inject from '@rollup/plugin-inject';
 import { defineConfig } from 'vite';
 import cssInjectedByJsPlugin from 'vite-plugin-css-injected-by-js';
 
+const __dirname = import.meta.dirname;
+
+const SOURCE_MAP_SUPPORT_GLOBAL = '(this.define||function(R,U){this.sourceMapSupport=U()})';
+const SOURCE_MAP_SUPPORT_GLOBAL_FIXED = '(globalThis.define||function(R,U){globalThis.sourceMapSupport=U()})';
+
+/**
+ * A line-preserving identity sourcemap for `code`.
+ *
+ * The transform below rewrites a single expression and never adds or removes a line, so mapping
+ * the start of every output line to the start of the same input line is accurate. Returning it
+ * keeps the bundler from warning that the plugin dropped the sourcemap.
+ */
+function identitySourceMap(code: string, id: string) {
+  const lineCount = code.split('\n').length;
+  // VLQ segments: `AAAA` = [col 0, source 0, line 0, col 0]; `AACA` advances the source line by 1.
+  const mappings = ['AAAA', ...Array(Math.max(lineCount - 1, 0)).fill('AACA')].join(';');
+  return { version: 3 as const, sources: [id], sourcesContent: [code], names: [], mappings };
+}
+
 export default defineConfig({
   build: {
     outDir: 'dist/lib',
     sourcemap: true,
     rollupOptions: {
-      plugins: [
-        inject({
+      transform: {
+        inject: {
           process: 'process/browser.js',
           Buffer: ['buffer', 'Buffer'],
-        }),
-      ],
+        },
+      },
       input: {
         'fdc3-compliance': path.resolve(__dirname, './src/test/index.ts'),
         channel: path.resolve(__dirname, './src/mock/channel.ts'),
@@ -52,16 +70,25 @@ export default defineConfig({
     'global.process': 'globalThis.process',
   },
   plugins: [
-    cssInjectedByJsPlugin(),
+    cssInjectedByJsPlugin({
+      // Only the `fdc3-compliance` entry imports CSS (mocha.css); without this the plugin
+      // picks an arbitrary entry among the many mock apps.
+      jsAssetsFilterFunction: outputChunk => outputChunk.fileName === 'fdc3-compliance.js',
+    }),
     {
       name: 'fix-source-map-support-global',
       transform(code, id) {
-        if (id.includes('browser-source-map-support')) {
-          return code.replace(
-            '(this.define||function(R,U){this.sourceMapSupport=U()})',
-            '(globalThis.define||function(R,U){globalThis.sourceMapSupport=U()})'
-          );
+        if (!id.includes('browser-source-map-support')) {
+          return;
+        }
+        if (!code.includes(SOURCE_MAP_SUPPORT_GLOBAL)) {
+          return;
         }
+        // The replacement is confined to one line, so line numbers are unchanged.
+        return {
+          code: code.replace(SOURCE_MAP_SUPPORT_GLOBAL, SOURCE_MAP_SUPPORT_GLOBAL_FIXED),
+          map: identitySourceMap(code, id),
+        };
       },
     },
   ],

toolbox/fdc3-workbench/package.json

@@ -2,6 +2,7 @@
   "name": "fdc3-workbench",
   "version": "3.0.0-alpha.2",
   "private": true,
+  "type": "module",
   "homepage": "https://fdc3.finos.org",
   "repository": {
     "type": "git",