fix(transform-shaker): fix export * as ns handling and guard structural children

change/@griffel-transform-shaker-7cb35a36-cfc0-46d5-82ea-c95ac660f49a.json

@@ -0,0 +1,7 @@
+{
+  "type": "patch",
+  "comment": "fix: protect structural children from removal, handle export * as ns correctly",
+  "packageName": "@griffel/transform-shaker",
+  "email": "olfedias@microsoft.com",
+  "dependentChangeType": "patch"
+}

packages/transform-shaker/src/__snapshots__/shaker.test.ts.snap

@@ -1,5 +1,7 @@
 // Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
 
+exports[`does not break export * as ns when requesting the namespace export 1`] = `"export * as ns from './module';"`;
+
 exports[`keeps ESM default import with batch export 1`] = `
 "import blank from './blank.jpg';
 export const __mkPreval = { backgroundImage: blank };"
@@ -141,6 +143,8 @@ const foo = bar();
 export const __linariaPreval = [foo];"
 `;
 
+exports[`removes \`export * as ns\` if not requested 1`] = `"export * from './other';"`;
+
 exports[`removes all 1`] = `
 "
 export const __linariaPreval = [];"

packages/transform-shaker/src/langs/core.ts

@@ -639,11 +639,25 @@ export const visitors = {
     if (!this.graph.imports.has(source)) {
       this.graph.imports.set(source, []);
     }
-    this.graph.importTypes.set(source, 'reexport');
+
     this.graph.addEdge(node, node.source);
 
-    // Create a sentinel node that represents this re-export
-    this.graph.reexports.push(node as unknown as IdentifierNode);
+    if (node.exported) {
+      // `export * as ns from "module"` — namespace re-export creates a single named export `ns`,
+      // it does NOT pass through individual exports like `export * from "module"` does.
+      const name = isIdentifier(node.exported)
+        ? node.exported.name
+        : (node.exported as unknown as { value: string }).value;
+
+      this.graph.addExport(name, node);
+      this.graph.addEdge(node, node.exported);
+
+      this.graph.importTypes.set(source, 'wildcard');
+    } else {
+      // `export * from "module"` — true wildcard re-export, passes through all exports
+      this.graph.importTypes.set(source, 'reexport');
+      this.graph.reexports.push(node as unknown as IdentifierNode);
+    }
 
     return 'ignore' as const;
   },

packages/transform-shaker/src/shaker.test.ts

@@ -376,3 +376,20 @@ it('keeps identifiers used as computed property keys', () => {
 
   expect(shaken).toMatchSnapshot();
 });
+
+it('removes `export * as ns` if not requested', () => {
+  const [shaken] = _shake(['unknownExport'])`
+    export * as ns from './module';
+    export * from './other';
+  `;
+
+  expect(shaken).toMatchSnapshot();
+});
+
+it('does not break export * as ns when requesting the namespace export', () => {
+  const [shaken] = _shake(['ns'])`
+    export * as ns from './module';
+  `;
+
+  expect(shaken).toMatchSnapshot();
+});

packages/transform-shaker/src/shaker.ts

@@ -9,6 +9,14 @@ import MagicString from 'magic-string';
 import { isNode, getVisitorKeys, debug } from './utils.js';
 import build from './graphBuilder.js';
 
+// Syntactically required children that must not be removed independently —
+// removing them produces invalid code (e.g. `export { X }` without `from "module"`).
+const STRUCTURAL_CHILDREN: Record<string, Set<string>> = {
+  ExportNamedDeclaration: new Set(['source']),
+  ExportAllDeclaration: new Set(['source', 'exported']),
+  ImportDeclaration: new Set(['source']),
+};
+
 function isStatementBody(nodeType: string, key: string): boolean {
   return (
     (nodeType === 'Program' && key === 'body') ||
@@ -130,7 +138,7 @@ function removeDeadCode(node: Node, alive: Set<Node>, s: MagicString, sourceCode
     } else if (isNode(subNode)) {
       if (alive.has(subNode)) {
         removeDeadCode(subNode, alive, s, sourceCode);
-      } else {
+      } else if (!STRUCTURAL_CHILDREN[node.type]?.has(key)) {
         s.remove(subNode.start, subNode.end);
       }
     }