Summary
The duplicate() function fails when attempting to duplicate complex nested structures that contain objects or function references. The same structures work correctly in Lucee and Adobe ColdFusion.
Environment
- BoxLang Version: 1.x
- Comparison Engines: Lucee 6.x, Adobe ColdFusion 2021+ (both work correctly)
Issue Description
When calling duplicate() on complex nested structures, BoxLang throws exceptions while Lucee and Adobe ColdFusion return valid duplicates. In BoxLang, the exceptions often lack a useful message.
Minimal Test Cases
1. Simple Structure (Works Everywhere)
simpleStruct = {
name = “test”,
value = 123,
nested = { inner = “value” }
};
duplicate(simpleStruct); // 
Expected: success
2. Complex Structure with Objects and Functions (Fails in BoxLang)
dummyObj = createObject(“component”, “Controller”);
dummyFunc = function(){ return “test”; };
complexStruct = {
controller = dummyObj,
handlers = [ dummyFunc ]
};
duplicate(complexStruct); // 
Fails in BoxLang
3. Framework-Like Structure Example
If you try duplicating a framework-level structure (e.g., application.wheels), the same error occurs:
try {
duplicate(application.wheels);
} catch (any e) {
writeDump(e);
}
Steps to Reproduce
- Run the code from Minimal Test Case 2 in BoxLang.
- Compare behavior in Lucee or Adobe ColdFusion.
- Optionally, run against a real framework struct like application.wheels to see the issue in practice.
Expected Behavior
- duplicate() should return a deep copy of the struct, including objects and function references.
- Behavior should match Lucee and Adobe CF.
- Exceptions, if any, should include descriptive error messages.
Actual Behavior in BoxLang
- duplicate() throws an exception on complex nested structures.
- Exceptions often lack any message (e.message is empty).
Impact
- Impacts frameworks (e.g., Wheels.dev) that rely on duplicating application state.
- Breaks migration of apps from Lucee/Adobe CF.
- Affects code relying on snapshot/backup of stateful data.
Workaround
Manual property-by-property copy is required:
function safeDuplicate(required struct original) {
local.result = {};
for (local.key in arguments.original) {
try {
local.result[local.key] = duplicate(arguments.original[local.key]);
} catch (any e) {
local.result[local.key] = “[NON_DUPLICATABLE]”;
}
}
return local.result;
}
Testing Instructions
- Copy-paste the minimal test cases above into BoxLang.
- Observe that duplicate() fails on the complex struct.
- Repeat the same tests in Lucee or Adobe CF.
- Compare the differences in behavior and error output.