fix(es/minifier): Respect top_retain for top-level functions (#8814)

swc-project · Apr 5, 2024 · 811308c · 811308c
1 parent 2a7a6e9
commit 811308c
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Showing 3 changed files with 9 additions and 4 deletions.
diff --git a/crates/swc_ecma_minifier/src/compress/optimize/unused.rs b/crates/swc_ecma_minifier/src/compress/optimize/unused.rs
@@ -511,6 +511,14 @@ impl Optimizer<'_> {
                     return;
                 }
 
+                if !self.may_remove_ident(ident) {
+                    log_abort!(
+                        "unused: Preserving function `{}` because it's top-level",
+                        ident.sym
+                    );
+                    return;
+                }
+
                 // If it is not used, drop it.
                 if self
                     .data

diff --git a/crates/swc_ecma_minifier/tests/TODO.txt b/crates/swc_ecma_minifier/tests/TODO.txt
@@ -88,7 +88,6 @@ drop_unused/delete_assign_1/input.js
 drop_unused/delete_assign_2/input.js
 drop_unused/double_assign_1/input.js
 drop_unused/double_assign_2/input.js
-drop_unused/drop_toplevel_all_retain/input.js
 drop_unused/drop_toplevel_funcs/input.js
 drop_unused/drop_toplevel_funcs_retain/input.js
 drop_unused/drop_toplevel_keep_assign/input.js

diff --git a/...es/swc_ecma_minifier/tests/terser/compress/drop_unused/drop_toplevel_all_retain/output.js b/...es/swc_ecma_minifier/tests/terser/compress/drop_unused/drop_toplevel_all_retain/output.js
@@ -1,8 +1,6 @@
 var a;
 function f(d) {
-    return function () {
-        2;
-    };
+    return function() {};
 }
 a = 2;
 console.log(3);