next-swc: fix ssg code elimination when used in render (#32709)

* next-swc: fix ssg code elimination when used in render

* simplify logic and add more thorough tests

* comment

* remove fold_export_default and fix JSX member expression

packages/next-swc/crates/core/src/next_ssg.rs

@@ -141,6 +141,31 @@ impl Fold for Analyzer<'_> {
         e
     }
 
+    fn fold_jsx_element(&mut self, jsx: JSXElement) -> JSXElement {
+        fn get_leftmost_id_member_expr(e: &JSXMemberExpr) -> Id {
+            match &e.obj {
+                JSXObject::Ident(i) => {
+                    i.to_id()
+                }
+                JSXObject::JSXMemberExpr(e) => {
+                    get_leftmost_id_member_expr(e)
+                }
+            }
+        }
+
+        match &jsx.opening.name {
+            JSXElementName::Ident(i) => {
+                self.add_ref(i.to_id());
+            }
+            JSXElementName::JSXMemberExpr(e) => {
+                self.add_ref(get_leftmost_id_member_expr(e));
+            }
+            _ => {}
+        }
+
+        jsx.fold_children_with(self)
+    }
+
     fn fold_fn_decl(&mut self, f: FnDecl) -> FnDecl {
         let old_in_data = self.in_data_fn;
 

packages/next-swc/crates/core/tests/fixture/ssg/getStaticProps/should-not-remove-import-used-in-render/input.js

@@ -0,0 +1,38 @@
+import { useState, useEffect } from 'react'
+import { Root, Children, JSXMemberExpression, AttributeValue, AttributeJSX, ValueInRender, ValueInEffect, UnusedInRender } from '../'
+
+export default function Test() {
+  const [x, setX] = useState(ValueInRender.value)
+  useEffect(() => {
+    setX(ValueInEffect.value)
+  }, [])
+
+  return (
+    <Root x={x}>
+      <div>
+        <Children attr={AttributeValue} jsx={<AttributeJSX />} />
+        <JSXMemberExpression.Deep.Property />
+      </div>
+    </Root>
+  )
+}
+
+export async function getStaticProps() {
+  return {
+    props: {
+      // simulate import usage inside getStaticProps
+      used: [
+        // these import references should not be removed
+        Root.value,
+        Children.value,
+        AttributeValue.value,
+        AttributeJSX.value,
+        ValueInRender.value,
+        ValueInEffect.value,
+        JSXMemberExpression.value,
+        // this import reference should be removed
+        UnusedInRender.value,
+      ],
+    }
+  }
+}

packages/next-swc/crates/core/tests/fixture/ssg/getStaticProps/should-not-remove-import-used-in-render/output.js

@@ -0,0 +1,15 @@
+import { useState, useEffect } from "react";
+import { Root, Children, JSXMemberExpression, AttributeValue, AttributeJSX, ValueInRender, ValueInEffect } from "../";
+export var __N_SSG = true;
+export default function Test() {
+    const [x, setX] = useState(ValueInRender.value);
+    useEffect(() => {
+        setX(ValueInEffect.value);
+    }, [])
+    return __jsx(Root, {
+      x: x
+    }, __jsx('div', null, __jsx(Children, {
+      attr: AttributeValue,
+      jsx: __jsx(AttributeJSX, null)
+    }), __jsx(JSXMemberExpression.Deep.Property, null)));
+}