Want to load multiple script files and THEN execute them

[amp64]

I want something like
eng.Load(script1, "1.js"); eng.Load(script2, "2.js"); eng.Execute(something);
I know I can just concat script1 and script2 and Execute that, but then I lose the source information ("1.js" etc). I'm missing something dumb here.
(I don't have control over the .js files content).
Right now I'm Executing each file in turn, but that's a problem.

[lahma]

Executing each file in turn with Execute is actually the intended approach — all scripts share the same global scope, so definitions from earlier scripts are available to later ones:

engine.Execute(script1, "1.js");
engine.Execute(script2, "2.js");
engine.Evaluate("someFunction()"); // can use anything defined in either script

Source information is preserved — errors will reference the correct file name and line numbers.

Could you describe what problem you're running into with executing sequentially?

[amp64]

I have an issue with two constructors of the same type, one causing the overridden method to not exist. Seems to be timing sensitive. Sample attached (in my real code this is in 3 files as commented), the call to cacheSpecialContent results in "Property 'cacheSpecialContent' of object is not a function".

(This is based on the JS code in the Blade Runner Branching HD DVD fyi).

My JS knowledge isn't great, but Copilot thinks the "other" constructor wipes out the definition.
Experiment.js

Note: in my real code the load order is contentplayer.js, contentplayer_mod.js, main.js

[lahma]

This is actually expected JavaScript behavior — it's not specific to Jint (V8/Node.js behaves the same way).

When function ContentPlayer() {} appears in a separate script evaluation, it creates a new function object with a fresh .prototype, replacing the previous binding. So cacheSpecialContent (added to the original prototype in content.js) is lost when contentplayer_mods.js redefines the constructor.

When concatenated into a single script, both function declarations are hoisted together — the second replaces the first before any code runs — so all prototype assignments end up on the same (final) function object.

Since you can't modify the JS files, a couple of workarounds:

1. Concatenate but track source offsets — you can use ScriptParsingOptions with SourceOffset to adjust line numbers per file for error reporting
2. Patch the prototype — after executing all scripts, copy any missing methods: execute a small fixup script that merges prototypes as needed
3. Use modules if the codebase can be adapted to that model

[amp64]

Thank you so much, I will look into #1. #2 would work for this disc but I'm not going to debug every HD DVD to figure them out, and #3 isn't an option because I need to pretend its 2005 :-)