feat(angular): support auto-serving known dynamic remotes (#10475)

packages/angular/src/builders/module-federation-dev-server/module-federation-dev-server.impl.ts

@@ -1,10 +1,59 @@
 import type { Schema } from './schema';
-import { Workspaces } from '@nrwl/devkit';
+import { ProjectConfiguration, Workspaces } from '@nrwl/devkit';
 import { scheduleTarget } from 'nx/src/adapter/ngcli-adapter';
 import { BuilderContext, createBuilder } from '@angular-devkit/architect';
 import { JsonObject } from '@angular-devkit/core';
 import { join } from 'path';
 import { executeWebpackServerBuilder } from '../webpack-server/webpack-server.impl';
+import { existsSync, readFileSync } from 'fs';
+
+function getDynamicRemotesIfExists(
+  context: BuilderContext,
+  p: ProjectConfiguration
+) {
+  // check for dynamic remotes
+  // we should only check for dynamic based on what we generate
+  // and fallback to empty array
+
+  const standardPathToGeneratedMFManifestJson = join(
+    context.workspaceRoot,
+    p.sourceRoot,
+    'assets/module-federation.manifest.json'
+  );
+  if (!existsSync(standardPathToGeneratedMFManifestJson)) {
+    return [];
+  }
+
+  const moduleFederationManifestJson = readFileSync(
+    standardPathToGeneratedMFManifestJson,
+    'utf-8'
+  );
+
+  if (moduleFederationManifestJson) {
+    // This should have shape of
+    // {
+    //   "remoteName": "remoteLocation",
+    // }
+    const parsedManifest = JSON.parse(moduleFederationManifestJson);
+    if (
+      !Object.keys(parsedManifest).every(
+        (key) =>
+          typeof key === 'string' && typeof parsedManifest[key] === 'string'
+      )
+    ) {
+      return [];
+    }
+
+    return Object.entries(parsedManifest).reduce(
+      (remotesArray, [remoteName, remoteLocation]) => [
+        ...remotesArray,
+        [remoteName, remoteLocation],
+      ],
+      []
+    );
+  }
+  return [];
+}
 
 export function executeModuleFederationDevServerBuilder(
   schema: Schema,
@@ -31,7 +80,11 @@ export function executeModuleFederationDevServerBuilder(
   }
 
   const { ...options } = schema;
-  const unparsedRemotes = mfeConfig.remotes.length > 0 ? mfeConfig.remotes : [];
+
+  let unparsedRemotes = mfeConfig.remotes.length > 0 ? mfeConfig.remotes : [];
+  const dynamicRemotes = getDynamicRemotesIfExists(context, p);
+  unparsedRemotes = [...unparsedRemotes, ...dynamicRemotes];
+
   const remotes = unparsedRemotes.map((a) => (Array.isArray(a) ? a[0] : a));
 
   const devServeRemotes = !options.devRemotes