test(integration): add basic remote build tests as poc

Author: joshuaellis

.github/workflows/integration-test.yml

@@ -0,0 +1,45 @@
+name: Integration Test
+
+on:
+  pull_request:
+    branches:
+      - main
+
+permissions:
+  pull-requests: read
+
+jobs:
+  integration-test:
+    name: Integration (vite ${{ matrix.vite-version }})
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        # This plugin does not yet correctly support version above 7.1.7
+        vite-version: ['5', '6', '7.1.7']
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+
+      - name: PNPM Install
+        uses: pnpm/action-setup@v4
+        with:
+          version: 10.28.2
+
+      - name: Setup Node
+        uses: actions/setup-node@v6
+        with:
+          node-version: 24
+          cache: 'pnpm'
+          registry-url: https://registry.npmjs.org/
+
+      - run: corepack enable
+
+      - name: Install NPM Dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Override vite version
+        run: pnpm add -Dw vite@${{ matrix.vite-version }}
+
+      - name: Run Integration Tests
+        run: pnpm test:integration

integration/build.test.ts

@@ -0,0 +1,78 @@
+import defu from 'defu';
+import { resolve } from 'path';
+import { build, Rollup } from 'vite';
+import { describe, expect, it } from 'vitest';
+import { federation } from '../src/index';
+import { findAsset, findChunk, getChunkNames } from './helpers/matchers';
+
+const FIXTURES = resolve(__dirname, 'fixtures');
+const BASIC_REMOTE = resolve(FIXTURES, 'basic-remote');
+
+async function buildFixture(optionsOverrides?: Partial<Parameters<typeof federation>[0]>) {
+  const defaultOptions = {
+    name: 'basicRemote',
+    filename: 'remoteEntry.js',
+    exposes: {
+      './exposed': resolve(BASIC_REMOTE, 'exposed-module.js'),
+    },
+    shared: {},
+    dts: false,
+  } satisfies Parameters<typeof federation>[0];
+
+  const mfOptions = defu(defaultOptions, optionsOverrides);
+
+  const result = await build({
+    root: BASIC_REMOTE,
+    logLevel: 'silent',
+    plugins: [federation(mfOptions)],
+    build: {
+      write: false,
+      target: 'chrome89',
+    },
+  });
+
+  // Vite returns RollupOutput[] only with multiple rollupOptions.output entries.
+  // Our test configs should never produce that — fail fast if they do.
+  expect(Array.isArray(result), 'E  xpected a single RollupOutput, not an array').toBe(false);
+  return result as Rollup.RollupOutput;
+}
+
+describe('build', () => {
+  describe('remote', () => {
+    it('produces a remoteEntry chunk', async () => {
+      const output = await buildFixture();
+      const chunks = getChunkNames(output);
+      expect(chunks.some((name) => name.includes('remoteEntry'))).toBe(true);
+    });
+
+    it('remoteEntry contains federation runtime init with correct name', async () => {
+      const output = await buildFixture();
+      const remoteEntry = findChunk(output, 'remoteEntry');
+      expect(remoteEntry).toBeDefined();
+      expect(remoteEntry!.code).toContain('basicRemote');
+      expect(remoteEntry!.code).toContain('moduleCache');
+    });
+
+    it('exposed module content is included in output', async () => {
+      const output = await buildFixture();
+      const allCode = output.output
+        .filter((o): o is Rollup.OutputChunk => o.type === 'chunk')
+        .map((c) => c.code)
+        .join('\n');
+
+      expect(allCode).toContain('Hello');
+    });
+
+    it('generates mf-manifest.json when manifest is enabled', async () => {
+      const manifestOutput = await buildFixture({
+        manifest: true,
+      });
+
+      const manifest = findAsset(manifestOutput, 'mf-manifest.json');
+      expect(manifest).toBeDefined();
+
+      const parsed = JSON.parse(manifest!.source as string);
+      expect(parsed).toHaveProperty('exposes');
+    });
+  });
+});

integration/fixtures/basic-remote/entry.js

@@ -0,0 +1,2 @@
+// Minimal app entry — just needs to exist for vite to build
+console.log('hello world');

integration/fixtures/basic-remote/exposed-module.js

@@ -0,0 +1,3 @@
+export function greet(name) {
+  return `Hello, ${name}!`;
+}

integration/fixtures/basic-remote/index.html

@@ -0,0 +1,7 @@
+<!doctype html>
+<html>
+  <body>
+    <div id="app"></div>
+    <script type="module" src="./entry.js"></script>
+  </body>
+</html>

integration/helpers/matchers.ts

@@ -0,0 +1,21 @@
+import type { Rollup } from 'vite';
+
+export function getChunkNames(output: Rollup.RollupOutput) {
+  return output.output
+    .filter((o): o is Rollup.OutputChunk => o.type === 'chunk')
+    .map((c) => c.fileName);
+}
+
+export function findChunk(output: Rollup.RollupOutput, test: string | RegExp) {
+  return output.output.find(
+    (o): o is Rollup.OutputChunk =>
+      o.type === 'chunk' &&
+      (typeof test === 'string' ? o.fileName.includes(test) : test.test(o.fileName))
+  );
+}
+
+export function findAsset(output: Rollup.RollupOutput, test: string) {
+  return output.output.find(
+    (o): o is Rollup.OutputAsset => o.type === 'asset' && o.fileName.includes(test)
+  );
+}

package.json

@@ -32,7 +32,8 @@
     "dev-nv": "pnpm -filter 'examples-nuxt-vite-host' -filter 'examples-vite-vite-remote' run dev",
     "preview-vv": "pnpm -filter 'examples-vite-vite*'  run preview",
     "multi-example": "pnpm --filter \"multi-example-*\" --parallel run start",
-    "test": "vitest",
+    "test": "vitest run src",
+    "test:integration": "vitest run integration",
     "e2e": "playwright test",
     "changeset": "changeset",
     "changeset:status": "changeset status"