Fix CJS optimizer (vercel#50376)

Avoid the new `VarDecl` being inserted multiple times.
hydRAnger · Jun 12, 2023 · 2d4330c · 2d4330c
1 parent caa96a2
commit 2d4330c
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Showing 3 changed files with 24 additions and 8 deletions.
diff --git a/packages/next-swc/crates/core/src/cjs_optimizer.rs b/packages/next-swc/crates/core/src/cjs_optimizer.rs
@@ -134,14 +134,22 @@ impl VisitMut for CjsOptimizer {
                                         definite: false,
                                     };
 
-                                    self.data.extra_stmts.push(Stmt::Decl(Decl::Var(Box::new(
-                                        VarDecl {
-                                            span: DUMMY_SP,
-                                            kind: VarDeclKind::Const,
-                                            declare: false,
-                                            decls: vec![var],
-                                        },
-                                    ))));
+                                    if !self.data.extra_stmts.clone().into_iter().any(|s| {
+                                        if let Stmt::Decl(Decl::Var(v)) = &s {
+                                            v.decls.iter().any(|d| d.name == var.name)
+                                        } else {
+                                            false
+                                        }
+                                    }) {
+                                        self.data.extra_stmts.push(Stmt::Decl(Decl::Var(
+                                            Box::new(VarDecl {
+                                                span: DUMMY_SP,
+                                                kind: VarDeclKind::Const,
+                                                declare: false,
+                                                decls: vec![var],
+                                            }),
+                                        )));
+                                    }
 
                                     *e = Expr::Ident(new_id.into());
                                 }

diff --git a/packages/next-swc/crates/core/tests/fixture/cjs-optimize/3/input.js b/packages/next-swc/crates/core/tests/fixture/cjs-optimize/3/input.js
@@ -0,0 +1,4 @@
+const server_1 = require('next/server')
+
+server_1.Response()
+server_1.Response.rewrite()
diff --git a/packages/next-swc/crates/core/tests/fixture/cjs-optimize/3/output.js b/packages/next-swc/crates/core/tests/fixture/cjs-optimize/3/output.js
@@ -0,0 +1,4 @@
+const Response = require("next/server/response").Response;
+;
+Response();
+Response.rewrite();