feat(rspack): add support for non-buildable libraries in external dependencies (#30606)

Parity with https://github.com/nrwl/nx/pull/30538

packages/rspack/src/plugins/utils/apply-base-config.ts

@@ -19,6 +19,7 @@ import { getTerserEcmaVersion } from './get-terser-ecma-version';
 import nodeExternals = require('webpack-node-externals');
 import { NormalizedNxAppRspackPluginOptions } from './models';
 import { isUsingTsSolutionSetup } from '@nx/js/src/utils/typescript/ts-solution-setup';
+import { isBuildableLibrary } from './is-lib-buildable';
 
 const IGNORED_RSPACK_WARNINGS = [
   /The comment file/i,
@@ -350,7 +351,40 @@ function applyNxDependentConfig(
     options.externalDependencies === 'all'
   ) {
     const modulesDir = `${options.root}/node_modules`;
-    externals.push(nodeExternals({ modulesDir }));
+    const graph = options.projectGraph;
+    const projectName = options.projectName;
+
+    const deps = graph?.dependencies?.[projectName] ?? [];
+
+    // Collect non-buildable TS project references so that they are bundled
+    // in the final output. This is needed for projects that are not buildable
+    // but are referenced by buildable projects. This is needed for the new TS
+    // solution setup.
+    const nonBuildableWorkspaceLibs = isUsingTsSolution
+      ? deps
+          .filter((dep) => {
+            const node = graph.nodes?.[dep.target];
+            if (!node || node.type !== 'lib') return false;
+
+            const hasBuildTarget = 'build' in (node.data?.targets ?? {});
+
+            if (hasBuildTarget) {
+              return false;
+            }
+
+            // If there is no build target we check the package exports to see if they reference
+            // source files
+            return !isBuildableLibrary(node);
+          })
+          .map(
+            (dep) => graph.nodes?.[dep.target]?.data?.metadata?.js?.packageName
+          )
+          .filter((name): name is string => !!name)
+      : [];
+
+    externals.push(
+      nodeExternals({ modulesDir, allowlist: nonBuildableWorkspaceLibs })
+    );
   } else if (Array.isArray(options.externalDependencies)) {
     externals.push(function (ctx, callback: Function) {
       if (options.externalDependencies.includes(ctx.request)) {

packages/rspack/src/plugins/utils/is-lib-buildable.ts

@@ -0,0 +1,58 @@
+import { type ProjectGraphProjectNode } from '@nx/devkit';
+
+function isSourceFile(path: string): boolean {
+  return ['.ts', '.tsx', '.mts', '.cts'].some((ext) => path.endsWith(ext));
+}
+
+function isBuildableExportMap(packageExports: any): boolean {
+  if (!packageExports || Object.keys(packageExports).length === 0) {
+    return false; // exports = {} → not buildable
+  }
+
+  const isCompiledExport = (value: unknown): boolean => {
+    if (typeof value === 'string') {
+      return !isSourceFile(value);
+    }
+    if (typeof value === 'object' && value !== null) {
+      return Object.entries(value).some(([key, subValue]) => {
+        if (
+          key === 'types' ||
+          key === 'development' ||
+          key === './package.json'
+        )
+          return false;
+        return typeof subValue === 'string' && !isSourceFile(subValue);
+      });
+    }
+    return false;
+  };
+
+  if (packageExports['.']) {
+    return isCompiledExport(packageExports['.']);
+  }
+
+  return Object.entries(packageExports).some(
+    ([key, value]) => key !== '.' && isCompiledExport(value)
+  );
+}
+
+/**
+ * Check if the library is buildable.
+ * @param node from the project graph
+ * @returns boolean
+ */
+export function isBuildableLibrary(node: ProjectGraphProjectNode): boolean {
+  if (!node.data.metadata?.js) {
+    return false;
+  }
+  const { packageExports, packageMain } = node.data.metadata.js;
+  // if we have exports only check this else fallback to packageMain
+  if (packageExports) {
+    return isBuildableExportMap(packageExports);
+  }
+  return (
+    typeof packageMain === 'string' &&
+    packageMain !== '' &&
+    !isSourceFile(packageMain)
+  );
+}