Failing test for #1696

packages/addon-dev/src/rollup-addon-dependencies.ts

@@ -11,8 +11,8 @@ const compilationModules = new Set(
   templateCompilationModules.map((m) => m.module)
 );
 
-function resolvableDependencies() {
-  let deps = new Set();
+function resolvableDependencies(): Set<string> {
+  let deps = new Set<string>();
   let pkg = readJsonSync('package.json');
   if (pkg.dependencies) {
     for (let name of Object.keys(pkg.dependencies)) {
@@ -28,11 +28,16 @@ function resolvableDependencies() {
 }
 
 export default function emberExternals(): Plugin {
-  let deps = resolvableDependencies();
+  let deps: Set<string>;
 
   return {
     name: 'ember-externals',
 
+    buildStart() {
+      this.addWatchFile('package.json');
+      deps = resolvableDependencies();
+    },
+
     async resolveId(source) {
       let pkgName = packageName(source);
       if (!pkgName) {

packages/addon-dev/src/rollup-keep-assets.ts

@@ -14,6 +14,12 @@ export default function keepAssets({
   return {
     name: 'copy-assets',
 
+    // Prior to https://github.com/rollup/rollup/pull/5270, we cannot call this
+    // from within `generateBundle`
+    buildStart() {
+      this.addWatchFile(from);
+    },
+
     // imports of assets should be left alone in the source code. This can cover
     // the case of .css as defined in the embroider v2 addon spec.
     async resolveId(source, importer, options) {

packages/addon-dev/src/rollup-public-assets.ts

@@ -11,6 +11,13 @@ export default function publicAssets(
 
   return {
     name: 'public-assets-bundler',
+
+    // Prior to https://github.com/rollup/rollup/pull/5270, we cannot call this
+    // from within `generateBundle`
+    buildStart() {
+      this.addWatchFile(path);
+    },
+
     generateBundle() {
       let pkg = readJsonSync('package.json');
       const filenames = walkSync(path, {

packages/addon-dev/src/rollup-public-entrypoints.ts

@@ -15,6 +15,8 @@ export default function publicEntrypoints(args: {
   return {
     name: 'addon-modules',
     async buildStart() {
+      this.addWatchFile(args.srcDir);
+
       let matches = walkSync(args.srcDir, {
         globs: [...args.include, '**/*.hbs', '**/*.ts', '**/*.gts', '**/*.gjs'],
       });

tests/scenarios/v2-addon-dev-watch-test.ts

@@ -3,6 +3,7 @@ import { baseV2Addon } from './scenarios';
 import type { PreparedApp } from 'scenario-tester';
 import { Scenarios } from 'scenario-tester';
 import fs from 'fs/promises';
+import { pathExists } from 'fs-extra';
 import QUnit from 'qunit';
 import merge from 'lodash/merge';
 import { DevWatcher, becomesModified, isNotModified } from './helpers';
@@ -185,6 +186,35 @@ Scenarios.fromProject(() => baseV2Addon())
             },
           });
         });
+
+        test('adding a new file triggers a re-build', async function (assert) {
+          watcher = new DevWatcher(addon);
+
+          await watcher.start();
+
+          const src = path.join(addon.dir, 'src/components/foo.js');
+          const dist = path.join(addon.dir, 'dist/components/foo.js');
+
+          assert.false(await pathExists(src), 'src/components/foo.js does not exist');
+          assert.false(await pathExists(dist), 'dist/components/foo.js does not exist');
+
+          await fs.writeFile(
+            src,
+            `
+            import Component from '@glimmer/component';
+            export default class FooComponent extends Component {}
+            `
+          );
+
+          assert.true(await pathExists(src), 'src/components/foo.js exists');
+
+          await watcher.nextBuild();
+
+          assert.true(
+            (await fs.readFile(dist)).includes('FooComponent'),
+            'dist/components/foo.js exists and has the right content'
+          );
+        });
       });
 
       test('the package.json *is* updated on a rebuild, since public assets changed', async function (assert) {