Stack Trace
The terminal printed a long error. Which line should I send to the AI?
$ node save.js
save.js:24
return items.map((row) => row);
^
TypeError: Cannot read properties of undefined (reading 'map')function handleSave(request) { const items = loadRows(request.file); return items.map((row) => row.total);}function loadRows(file) { const items = readFile(file); return items.map((row) => row);}This is your own file: items is undefined and line 24 calls .map on it. Start here.
A stack trace usually lists the frame nearest the throw first, followed by its callers. Start near the top and find a frame in your own file; frames locate clues but do not prove the root cause.
The frame near the throw is usually near the top: The frame nearest the throw is usually near the top, followed by its callers; a runtime or third-party frame may appear first.
Look for your own files only: The trace can mix in runtime and third-party library internals. Only frames from your own files correspond to code you wrote and can be a starting point for a fix.
The error type points at a value: TypeError: Cannot read properties of undefined means code tried to read a property from undefined; check the failing line and actual data to find which value was undefined.
You can say this to an AI Agent
Running node save.js reports a TypeError, and the stack points to my loadRows (save.js:24:21). Start near that frame, then trace its caller and input data to find where undefined first appears; rerun after the fix and verify the result.
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