Fix #103

Author: MichaelXF

src/transforms/dispatcher.ts

@@ -157,6 +157,16 @@ export default class Dispatcher extends Transform {
                     return "EXIT";
                   }
                 }
+
+                // Avoid functions with function expressions as they have a different scope
+                if (
+                  (oo.type === "FunctionExpression" ||
+                    oo.type === "ArrowFunctionExpression") &&
+                  pp.find((x) => x == o.params)
+                ) {
+                  illegalFnNames.add(name);
+                  return "EXIT";
+                }
               });
 
               functionDeclarations[name] = [o, p];

test/transforms/dispatcher.test.ts

@@ -373,3 +373,30 @@ test("Variant #16: Don't change functions that use 'eval'", async () => {
 
   expect(TEST_OUTPUT).toStrictEqual(2);
 });
+
+// https://github.com/MichaelXF/js-confuser/issues/103
+test("Variant #17: Don't break default parameter, function expression", async () => {
+  var output = await JsConfuser(
+    `
+  var X = "Correct Value";
+
+function printX(
+  getX = function () {
+    return X;
+  }
+) {
+  var X = "Incorrect Value";
+
+  TEST_OUTPUT = getX();
+}
+
+printX();
+  `,
+    { target: "node", dispatcher: true }
+  );
+
+  var TEST_OUTPUT;
+  eval(output);
+
+  expect(TEST_OUTPUT).toStrictEqual("Correct Value");
+});