chore: warn if shared dependency is resolved to somewhere (#354)

src/index.ts

@@ -1,6 +1,7 @@
 import defu from 'defu';
 import { Plugin } from 'vite';
 import addEntry from './plugins/pluginAddEntry';
+import { checkAliasConflicts } from './plugins/pluginCheckAliasConflicts';
 import { PluginDevProxyModuleTopLevelAwait } from './plugins/pluginDevProxyModuleTopLevelAwait';
 import pluginManifest from './plugins/pluginMFManifest';
 import pluginModuleParseEnd from './plugins/pluginModuleParseEnd';
@@ -41,6 +42,7 @@ function federation(mfUserOptions: ModuleFederationOptions): Plugin[] {
       },
     },
     aliasToArrayPlugin,
+    checkAliasConflicts({ shared }),
     normalizeOptimizeDepsPlugin,
     ...addEntry({
       entryName: 'remoteEntry',

src/plugins/__tests__/pluginCheckAliasConflicts.test.ts

@@ -0,0 +1,199 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+import { checkAliasConflicts } from '../pluginCheckAliasConflicts';
+
+describe('pluginCheckAliasConflicts', () => {
+  let consoleWarnSpy: any;
+  let mockLogger: any;
+
+  beforeEach(() => {
+    consoleWarnSpy = vi.spyOn(console, 'warn').mockImplementation(() => {});
+    mockLogger = {
+      warn: vi.fn(),
+      info: vi.fn(),
+      error: vi.fn(),
+    };
+  });
+
+  afterEach(() => {
+    consoleWarnSpy.mockRestore();
+  });
+
+  it('should warn when alias conflicts with shared module', () => {
+    const plugin = checkAliasConflicts({
+      shared: {
+        vue: {
+          name: 'vue',
+          version: '3.2.45',
+          scope: 'default',
+          from: 'host',
+          shareConfig: {
+            requiredVersion: '^3.2.45',
+          } as any,
+        },
+        pinia: {
+          name: 'pinia',
+          version: '2.0.28',
+          scope: 'default',
+          from: 'host',
+          shareConfig: {
+            requiredVersion: '^2.0.28',
+          } as any,
+        },
+      },
+    });
+
+    const mockConfig = {
+      logger: mockLogger,
+      resolve: {
+        alias: [
+          {
+            find: 'vue',
+            replacement: '/path/to/project/node_modules/vue/dist/vue.runtime.esm-bundler.js',
+          },
+          {
+            find: 'pinia',
+            replacement: '/path/to/project/node_modules/pinia/dist/pinia.mjs',
+          },
+          {
+            find: 'shared',
+            replacement: '/path/to/project/shared/shared',
+          },
+        ],
+      },
+    };
+
+    plugin.configResolved!(mockConfig as any);
+
+    expect(mockLogger.warn).toHaveBeenCalledTimes(5);
+    expect(mockLogger.warn).toHaveBeenCalledWith(
+      '\n[Module Federation] Detected alias conflicts with shared modules:'
+    );
+    expect(mockLogger.warn).toHaveBeenCalledWith(
+      expect.stringContaining('Shared module "vue" is aliased by "vue"')
+    );
+    expect(mockLogger.warn).toHaveBeenCalledWith(
+      expect.stringContaining('Shared module "pinia" is aliased by "pinia"')
+    );
+  });
+
+  it('should not warn when no alias conflicts exist', () => {
+    const plugin = checkAliasConflicts({
+      shared: {
+        vue: {
+          name: 'vue',
+          version: '3.2.45',
+          scope: 'default',
+          from: 'host',
+          shareConfig: {
+            requiredVersion: '^3.2.45',
+          } as any,
+        },
+      },
+    });
+
+    const mockConfig = {
+      logger: mockLogger,
+      resolve: {
+        alias: [
+          {
+            find: 'shared',
+            replacement: '/path/to/project/shared/shared',
+          },
+        ],
+      },
+    };
+
+    plugin.configResolved!(mockConfig as any);
+
+    expect(mockLogger.warn).not.toHaveBeenCalled();
+  });
+
+  it('should not warn when shared is empty', () => {
+    const plugin = checkAliasConflicts({
+      shared: {},
+    });
+
+    const mockConfig = {
+      logger: mockLogger,
+      resolve: {
+        alias: [
+          {
+            find: 'vue',
+            replacement: '/path/to/project/node_modules/vue/dist/vue.runtime.esm-bundler.js',
+          },
+        ],
+      },
+    };
+
+    plugin.configResolved!(mockConfig as any);
+
+    expect(mockLogger.warn).not.toHaveBeenCalled();
+  });
+
+  it('should handle regex alias patterns', () => {
+    const plugin = checkAliasConflicts({
+      shared: {
+        react: {
+          name: 'react',
+          version: '18.0.0',
+          scope: 'default',
+          from: 'host',
+          shareConfig: {
+            requiredVersion: '^18.0.0',
+          } as any,
+        },
+      },
+    });
+
+    const mockConfig = {
+      logger: mockLogger,
+      resolve: {
+        alias: [
+          {
+            find: /^react$/,
+            replacement: '/path/to/project/node_modules/react/index.js',
+          },
+        ],
+      },
+    };
+
+    plugin.configResolved!(mockConfig as any);
+
+    expect(mockLogger.warn).toHaveBeenCalled();
+    expect(mockLogger.warn).toHaveBeenCalledWith(
+      expect.stringContaining('Shared module "react" is aliased')
+    );
+  });
+
+  it('should handle shared modules with trailing slash', () => {
+    const plugin = checkAliasConflicts({
+      shared: {
+        'lodash/': {
+          name: 'lodash/',
+          version: '4.17.21',
+          scope: 'default',
+          from: 'host',
+          shareConfig: {
+            requiredVersion: '^4.17.21',
+          } as any,
+        },
+      },
+    });
+
+    const mockConfig = {
+      logger: mockLogger,
+      resolve: {
+        alias: [
+          {
+            find: 'lodash',
+            replacement: '/path/to/project/node_modules/lodash',
+          },
+        ],
+      },
+    };
+
+    plugin.configResolved!(mockConfig as any);
+
+    expect(mockLogger.warn).toHaveBeenCalled();
+  });
+});

src/plugins/pluginCheckAliasConflicts.ts

@@ -0,0 +1,59 @@
+import type { Alias, Plugin } from 'vite';
+import { NormalizedShared } from '../utils/normalizeModuleFederationOptions';
+
+/**
+ * Check if user-defined alias conflicts with shared modules
+ * This should run after aliasToArrayPlugin to ensure alias is an array
+ */
+export function checkAliasConflicts(options: { shared?: NormalizedShared }): Plugin {
+  const { shared = {} } = options;
+  const sharedKeys = Object.keys(shared);
+
+  return {
+    name: 'check-alias-conflicts',
+    configResolved(config: any) {
+      if (sharedKeys.length === 0) return;
+
+      const userAliases: Alias[] = config.resolve?.alias || [];
+      const conflicts: Array<{ sharedModule: string; alias: string; target: string }> = [];
+
+      for (const sharedKey of sharedKeys) {
+        for (const aliasEntry of userAliases) {
+          const findPattern = aliasEntry.find;
+          const replacement = aliasEntry.replacement;
+
+          // Skip if replacement is not a string (e.g., customResolver)
+          if (typeof replacement !== 'string') continue;
+
+          // Check if alias pattern matches the shared module
+          let isMatch = false;
+          if (typeof findPattern === 'string') {
+            isMatch = findPattern === sharedKey || sharedKey.startsWith(findPattern + '/');
+          } else if (findPattern instanceof RegExp) {
+            isMatch = findPattern.test(sharedKey);
+          }
+
+          if (isMatch) {
+            conflicts.push({
+              sharedModule: sharedKey,
+              alias: String(findPattern),
+              target: replacement,
+            });
+          }
+        }
+      }
+
+      if (conflicts.length > 0) {
+        config.logger.warn('\n[Module Federation] Detected alias conflicts with shared modules:');
+        conflicts.forEach(({ sharedModule, alias, target }) => {
+          config.logger.warn(
+            `  - Shared module "${sharedModule}" is aliased by "${alias}" to "${target}"`
+          );
+        });
+        config.logger.warn(
+          "  This may cause runtime errors as the shared module will bypass Module Federation's sharing mechanism."
+        );
+      }
+    },
+  };
+}