fix(next-custom-transforms): preserve all declarators in multi-declarator export statements (#86552)

Author: pyrytakala

crates/next-custom-transforms/src/transforms/next_ssg.rs

@@ -144,9 +144,11 @@ impl VisitMut for Analyzer<'_> {
                 return;
             }
 
-            if let Pat::Ident(id) = &d.decls[0].name {
-                if !SSG_EXPORTS.contains(&&*id.id.sym) {
-                    self.add_ref(id.to_id());
+            for decl in &d.decls {
+                if let Pat::Ident(id) = &decl.name {
+                    if !SSG_EXPORTS.contains(&&*id.id.sym) {
+                        self.add_ref(id.to_id());
+                    }
                 }
             }
         }

crates/next-custom-transforms/tests/fixture/ssg/getStaticProps/multi-declarator-export/input.js

@@ -0,0 +1,14 @@
+export const a = 1,
+  b = 2
+
+export async function getStaticProps() {
+  return {
+    props: {
+      sum: a + b,
+    },
+  }
+}
+
+export default function Page() {
+  return <div>Test</div>
+}

crates/next-custom-transforms/tests/fixture/ssg/getStaticProps/multi-declarator-export/output.js

@@ -0,0 +1,5 @@
+export var __N_SSG = true;
+export const a = 1, b = 2;
+export default function Page() {
+    return __jsx("div", null, "Test");
+}