fix: skip all federation plugins in test env (#595)

---------

Co-authored-by: gioboa <giorgiob.boa@gmail.com>

Author: JammingBen

src/__tests__/index.test.ts

@@ -1,5 +1,5 @@
 import type { Plugin } from 'vite';
-import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { afterAll, beforeEach, describe, expect, it, vi } from 'vitest';
 import { getLoadShareImportId } from '../virtualModules/virtualShared_preBuild';
 
 const { hasPackageDependencyMock, mfWarn } = vi.hoisted(() => ({
@@ -99,6 +99,37 @@ function getModuleFederationVitePlugin(): Plugin {
   return plugin;
 }
 
+describe('federation in test environment', () => {
+  const originalEnv = process.env;
+
+  beforeEach(() => {
+    process.env = {};
+  });
+
+  afterAll(() => {
+    process.env = originalEnv;
+  });
+
+  it('returns empty plugin array when in test environment', () => {
+    process.env.NODE_ENV = 'test';
+    const plugins = federation({
+      name: 'host',
+      filename: 'remoteEntry.js',
+    });
+    expect(plugins).toEqual([]);
+  });
+
+  it('returns plugins when MFE_VITE_NO_TEST_ENV_CHECK is true', () => {
+    process.env.NODE_ENV = 'test';
+    process.env.MFE_VITE_NO_TEST_ENV_CHECK = 'true';
+    const plugins = federation({
+      name: 'host',
+      filename: 'remoteEntry.js',
+    });
+    expect(plugins.length).toBeGreaterThan(0);
+  });
+});
+
 describe('module-federation-esm-shims', () => {
   beforeEach(() => {
     vi.clearAllMocks();
@@ -213,7 +244,10 @@ describe('vite:module-federation-early-init', () => {
     };
 
     const configHook = typeof plugin.config === 'function' ? plugin.config : plugin.config?.handler;
-    configHook?.call({ meta: {} } as any, config, { command: 'serve', mode: 'test' });
+    configHook?.call({ meta: {} } as any, config, {
+      command: 'serve',
+      mode: 'test',
+    });
 
     expect(config.optimizeDeps.include).toContain(getPreBuildLibImportId('vue'));
     expect(config.optimizeDeps.include).toContain(getLoadShareImportId('vue', false, 'serve'));
@@ -253,7 +287,10 @@ describe('vite:module-federation-early-init', () => {
     };
 
     const configHook = typeof plugin.config === 'function' ? plugin.config : plugin.config?.handler;
-    configHook?.call({ meta: {} } as any, config, { command: 'build', mode: 'test' });
+    configHook?.call({ meta: {} } as any, config, {
+      command: 'build',
+      mode: 'test',
+    });
 
     expect(config.define.ENV_TARGET).toBe('undefined');
   });
@@ -273,7 +310,10 @@ describe('vite:module-federation-early-init', () => {
     };
 
     const configHook = typeof plugin.config === 'function' ? plugin.config : plugin.config?.handler;
-    configHook?.call({ meta: {} } as any, config, { command: 'build', mode: 'test' });
+    configHook?.call({ meta: {} } as any, config, {
+      command: 'build',
+      mode: 'test',
+    });
 
     expect(config.define.ENV_TARGET).toBe('"node"');
   });
@@ -304,7 +344,10 @@ describe('vite:module-federation-early-init with import: false', () => {
     };
 
     const configHook = typeof plugin.config === 'function' ? plugin.config : plugin.config?.handler;
-    configHook?.call({ meta: {} } as any, config, { command: 'serve', mode: 'test' });
+    configHook?.call({ meta: {} } as any, config, {
+      command: 'serve',
+      mode: 'test',
+    });
 
     // Should not include prebuild or loadShare for import: false deps
     const includeStr = config.optimizeDeps.include.join(',');

src/index.ts

@@ -16,6 +16,7 @@ import { proxySharedModule } from './plugins/pluginProxySharedModule_preBuild';
 import { pluginRemoteNamedExports } from './plugins/pluginRemoteNamedExports';
 import pluginVarRemoteEntry from './plugins/pluginVarRemoteEntry';
 import aliasToArrayPlugin from './utils/aliasToArrayPlugin';
+import { isTestEnv } from './utils/isTestEnv';
 import { resolveProxyAlias } from './utils/bundleHelpers';
 import {
   isFederationControlChunk,
@@ -167,6 +168,7 @@ function createEarlyVirtualModulesPlugin(options: NormalizedModuleFederationOpti
 }
 
 function federation(mfUserOptions: ModuleFederationOptions): Plugin[] {
+  if (isTestEnv()) return [];
   const options = normalizeModuleFederationOptions(mfUserOptions);
   const isVinext = hasPackageDependency('vinext');
   const { name, remotes, shared, filename, hostInitInjectLocation } = options;

src/utils/__tests__/isTestEnv.test.ts

@@ -0,0 +1,39 @@
+import { afterAll, beforeEach, describe, expect, it } from 'vitest';
+import { isTestEnv } from '../isTestEnv';
+
+describe('isTestEnv', () => {
+  const originalEnv = process.env;
+
+  beforeEach(() => {
+    process.env = {};
+  });
+
+  afterAll(() => {
+    process.env = originalEnv;
+  });
+
+  it('returns true when NODE_ENV is test', () => {
+    process.env.NODE_ENV = 'test';
+    expect(isTestEnv()).toBe(true);
+  });
+
+  it('returns true when VITEST is set', () => {
+    process.env.VITEST = 'true';
+    expect(isTestEnv()).toBe(true);
+  });
+
+  it('returns true when JEST_WORKER_ID is set', () => {
+    process.env.JEST_WORKER_ID = '1';
+    expect(isTestEnv()).toBe(true);
+  });
+
+  it('returns false when no test env vars are set', () => {
+    expect(isTestEnv()).toBe(false);
+  });
+
+  it('returns false when MFE_VITE_NO_TEST_ENV_CHECK is true, even in test env', () => {
+    process.env.NODE_ENV = 'test';
+    process.env.MFE_VITE_NO_TEST_ENV_CHECK = 'true';
+    expect(isTestEnv()).toBe(false);
+  });
+});

src/utils/isTestEnv.ts

@@ -0,0 +1,13 @@
+/**
+ * Detects whether the current process is running in a test environment
+ * Set `MFE_VITE_NO_TEST_ENV_CHECK=true` to load federation plugins during tests.
+ */
+export function isTestEnv() {
+  if (process.env.MFE_VITE_NO_TEST_ENV_CHECK === 'true') return false;
+
+  return (
+    process.env.NODE_ENV === 'test' ||
+    process.env.VITEST != null ||
+    process.env.JEST_WORKER_ID != null
+  );
+}

vitest.config.ts

@@ -4,5 +4,8 @@ export default defineConfig({
   test: {
     globals: true,
     exclude: ['**/e2e/**', '**/node_modules/**'],
+    env: {
+      MFE_VITE_NO_TEST_ENV_CHECK: 'true',
+    },
   },
 });