Read the Trace

LLMs love to see "TypeError" and generate a generic fix without reading the trace. Don't.

• Find the deepest frame in YOUR code — not the library frame at the top. That's where the bad value entered.
• Read the actual values: what was null/undefined/wrong-type, and where it came from.
• Trace it one level up: why was that value bad? The root is usually 1-2 frames above the throw.
• Reproduce with that exact input before fixing. A TypeError can mean a hundred things. The trace tells you which one — read all of it, including the "caused by".