feat(angular): add mfe helpers for sharing workspace libraries

packages/angular/package.json

@@ -21,7 +21,8 @@
     "./generators": "./generators.js",
     "./executors": "./executors.js",
     "./tailwind": "./tailwind.js",
-    "./src/generators/utils": "./src/generators/utils/index.js"
+    "./src/generators/utils": "./src/generators/utils/index.js",
+    "./mfe-utils": "./src/utils/mfe-webpack.js"
   },
   "author": "Victor Savkin",
   "license": "MIT",

packages/angular/src/builders/webpack-server/webpack-server.impl.ts

@@ -13,6 +13,11 @@ import { normalizeOptions } from './lib';
 import type { Schema } from './schema';
 
 export function webpackServer(schema: Schema, context: BuilderContext) {
+  process.env.NX_TSCONFIG_PATH = joinPathFragments(
+    context.workspaceRoot,
+    'tsconfig.base.json'
+  );
+
   const options = normalizeOptions(schema);
   const workspaceConfig = new Workspaces(
     context.workspaceRoot

packages/angular/src/utils/mfe-webpack.spec.ts

@@ -0,0 +1,67 @@
+jest.mock('fs');
+jest.mock('@nrwl/workspace');
+import * as fs from 'fs';
+import * as workspace from '@nrwl/workspace';
+
+import { shareWorkspaceLibraries } from './mfe-webpack';
+
+describe('MFE Webpack Utils', () => {
+  afterEach(() => jest.clearAllMocks());
+
+  it('should error when the tsconfig file does not exist', () => {
+    // ARRANGE
+    (fs.existsSync as jest.Mock).mockReturnValue(false);
+
+    // ACT
+    try {
+      shareWorkspaceLibraries(['@myorg/shared']);
+    } catch (error) {
+      // ASSERT
+      expect(error.message).toEqual(
+        'NX MFE: TsConfig Path for workspace libraries does not exist! (undefined)'
+      );
+    }
+  });
+
+  it('should create an object with correct setup', () => {
+    // ARRANGE
+    (fs.existsSync as jest.Mock).mockReturnValue(true);
+    (workspace.readTsConfig as jest.Mock).mockReturnValue({
+      options: {
+        paths: {
+          '@myorg/shared': ['/libs/shared/src/index.ts'],
+        },
+      },
+    });
+
+    // ACT
+    const sharedLibraries = shareWorkspaceLibraries(['@myorg/shared']);
+    // ASSERT
+    expect(sharedLibraries.getAliases()).toHaveProperty('@myorg/shared');
+    expect(sharedLibraries.getAliases()['@myorg/shared']).toContain(
+      'libs/shared/src/index.ts'
+    );
+    expect(sharedLibraries.getLibraries()).toEqual({
+      '@myorg/shared': {
+        eager: undefined,
+        requiredVersion: false,
+      },
+    });
+  });
+
+  it('should create an object with empty setup when tsconfig does not contain the shared lib', () => {
+    // ARRANGE
+    (fs.existsSync as jest.Mock).mockReturnValue(true);
+    (workspace.readTsConfig as jest.Mock).mockReturnValue({
+      options: {
+        paths: {},
+      },
+    });
+
+    // ACT
+    const sharedLibraries = shareWorkspaceLibraries(['@myorg/shared']);
+    // ASSERT
+    expect(sharedLibraries.getAliases()).toEqual({});
+    expect(sharedLibraries.getLibraries()).toEqual({});
+  });
+});

packages/angular/src/utils/mfe-webpack.ts

@@ -0,0 +1,73 @@
+import { readTsConfig } from '@nrwl/workspace';
+import { existsSync } from 'fs';
+import { NormalModuleReplacementPlugin } from 'webpack';
+import { appRootPath as rootPath } from '@nrwl/tao/src/utils/app-root';
+import { normalizePath, joinPathFragments } from '@nrwl/devkit';
+import { dirname } from 'path';
+import { ParsedCommandLine } from 'typescript';
+
+export function shareWorkspaceLibraries(
+  libraries: string[],
+  tsConfigPath = process.env.NX_TSCONFIG_PATH
+) {
+  if (!existsSync(tsConfigPath)) {
+    throw new Error(
+      `NX MFE: TsConfig Path for workspace libraries does not exist! (${tsConfigPath})`
+    );
+  }
+
+  const tsConfig: ParsedCommandLine = readTsConfig(tsConfigPath);
+  const tsconfigPathAliases = tsConfig.options?.paths;
+
+  if (!tsconfigPathAliases) {
+    return {
+      getAliases: () => [],
+      getLibraries: () => [],
+      getReplacementPlugin: () =>
+        new NormalModuleReplacementPlugin(/./, () => {}),
+    };
+  }
+
+  const pathMappings: { name: string; path: string }[] = [];
+  for (const [key, paths] of Object.entries(tsconfigPathAliases)) {
+    if (libraries && libraries.includes(key)) {
+      const pathToLib = normalizePath(joinPathFragments(rootPath, paths[0]));
+      pathMappings.push({
+        name: key,
+        path: pathToLib,
+      });
+    }
+  }
+
+  return {
+    getAliases: () =>
+      pathMappings.reduce(
+        (aliases, library) => ({ ...aliases, [library.name]: library.path }),
+        {}
+      ),
+    getLibraries: (eager?: boolean) =>
+      pathMappings.reduce(
+        (libraries, library) => ({
+          ...libraries,
+          [library.name]: { requiredVersion: false, eager },
+        }),
+        {}
+      ),
+    getReplacementPlugin: () =>
+      new NormalModuleReplacementPlugin(/./, (req) => {
+        if (!req.request.startsWith('.')) {
+          return;
+        }
+
+        const from = req.context;
+        const to = normalizePath(joinPathFragments(req.context, req.request));
+
+        for (const library of pathMappings) {
+          const libFolder = normalizePath(dirname(library.path));
+          if (!from.startsWith(libFolder) && to.startsWith(libFolder)) {
+            req.request = library.name;
+          }
+        }
+      }),
+  };
+}