fix corner case in unused (#5920)

fixes #5918
mishoo · Aug 14, 2024 · abefd94 · abefd94
1 parent f34fbb2
commit abefd94
Show file tree

Hide file tree

Showing 2 changed files with 33 additions and 0 deletions.
diff --git a/lib/compress.js b/lib/compress.js
@@ -7253,6 +7253,10 @@ Compressor.prototype.compress = function(node) {
  var def = node.definition();
  var_defs[def.id] = (var_defs[def.id] || 0) + 1;
  assignments.add(def.id, node);
+ var fixed = node.fixed_value(true);
+ if (fixed && fixed.tail_node().operator == "=") {
+ verify_safe_usage(def, node, value_modified[def.id]);
+ }
  return true;
  }
  if (node instanceof AST_SymbolImport) {

diff --git a/test/compress/drop-unused.js b/test/compress/drop-unused.js
@@ -3870,3 +3870,32 @@ issue_5908_2: {
  }
  expect_stdout: "PASS"
 }
+
+issue_5918: {
+ options = {
+ pure_getters: "strict",
+ reduce_vars: true,
+ unused: true,
+ }
+ input: {
+ var a;
+ (function(b) {
+ b.p = 42;
+ })(a = function() {
+ arguments;
+ });
+ for (var i in a)
+ console.log("PASS");
+ }
+ expect: {
+ var a;
+ (function(b) {
+ b.p = 42;
+ })(a = function() {
+ arguments;
+ });
+ for (var i in a)
+ console.log("PASS");
+ }
+ expect_stdout: "PASS"
+}