fix corner case in reduce_vars (#5875)

fixes #5874
mishoo · Jul 10, 2024 · 2c73103 · 2c73103
1 parent 124c4d3
commit 2c73103
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Showing 2 changed files with 59 additions and 22 deletions.
diff --git a/lib/compress.js b/lib/compress.js
@@ -6258,26 +6258,8 @@ Compressor.prototype.compress = function(node) {
                     return false;
             return true;
         }
-        def(AST_Node, return_false);
-        def(AST_Array, function(scope) {
-            return all_constant(this.elements, scope);
-        });
-        def(AST_Binary, function(scope) {
-            return this.left.is_constant_expression(scope)
-                && this.right.is_constant_expression(scope)
-                && can_drop_op(this);
-        });
-        def(AST_Class, function(scope) {
-            var base = this.extends;
-            if (base && !safe_for_extends(base)) return false;
-            return all_constant(this.properties, scope);
-        });
-        def(AST_ClassProperty, function(scope) {
-            return typeof this.key == "string" && (!this.value || this.value.is_constant_expression(scope));
-        });
-        def(AST_Constant, return_true);
-        def(AST_Lambda, function(scope) {
-            var self = this;
+
+        function walk_scoped(self, scope) {
             var result = true;
             var scopes = [];
             self.walk(new TreeWalker(function(node, descend) {
@@ -6294,7 +6276,7 @@ Compressor.prototype.compress = function(node) {
                         result = false;
                         return true;
                     }
-                    if (self.variables.has(node.name)) return true;
+                    if (self.variables && self.variables.has(node.name)) return true;
                     var def = node.definition();
                     if (member(def.scope, scopes)) return true;
                     if (scope && !def.redefined()) {
@@ -6315,6 +6297,31 @@ Compressor.prototype.compress = function(node) {
                 }
             }));
             return result;
+        }
+
+        def(AST_Node, return_false);
+        def(AST_Array, function(scope) {
+            return all_constant(this.elements, scope);
+        });
+        def(AST_Binary, function(scope) {
+            return this.left.is_constant_expression(scope)
+                && this.right.is_constant_expression(scope)
+                && can_drop_op(this);
+        });
+        def(AST_Class, function(scope) {
+            var base = this.extends;
+            if (base && !safe_for_extends(base)) return false;
+            return all_constant(this.properties, scope);
+        });
+        def(AST_ClassProperty, function(scope) {
+            if (typeof this.key != "string") return false;
+            var value = this.value;
+            if (!value) return true;
+            return walk_scoped(value, scope);
+        });
+        def(AST_Constant, return_true);
+        def(AST_Lambda, function(scope) {
+            return walk_scoped(this, scope);
         });
         def(AST_Object, function(scope) {
             return all_constant(this.properties, scope);
@@ -12704,7 +12711,8 @@ Compressor.prototype.compress = function(node) {
                         single_use = false;
                     } else if (fixed.has_side_effects(compressor)) {
                         single_use = false;
-                    } else if (compressor.option("ie") && fixed instanceof AST_Class) {
+                    } else if (fixed instanceof AST_Class
+                        && (compressor.option("ie") || !fixed.is_constant_expression(self.scope))) {
                         single_use = false;
                     }
                     if (single_use) fixed.parent_scope = self.scope;

diff --git a/test/compress/classes.js b/test/compress/classes.js
@@ -4030,3 +4030,32 @@ issue_5747_2: {
     expect_stdout: "function"
     node_version: ">=16"
 }
+
+issue_5874: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        console.log(Object.keys(function() {
+            class A {
+                [a];
+            }
+            a = "FAIL";
+            return new A();
+        }())[0]);
+    }
+    expect: {
+        var a = "PASS";
+        console.log(Object.keys(function() {
+            class A {
+                [a];
+            }
+            a = "FAIL";
+            return new A();
+        }())[0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=12"
+}