Less guessing.
More “found it.”
Debugging Detective Lab
Learn to follow evidence, test a theory and fix the right thing.
Small bugs. Real JavaScript. Skills for every project.
≠ 30
The values look right.
The types tell a different story.
Everything runs locally. No accounts, AI services or external requests.
A bug is a question. Find the evidence.
Watch the value change, one step at a time.
A teaching trace of the small sum algorithm below. Change the inputs and compare numeric conversion with direct addition. This is not a general-purpose debugger.
- Current line
- Index i
- Accumulator
- Type
Twelve habits that make bugs less mysterious.
Continue with the official Chrome DevTools debugging walkthrough ↗.
Build a bug report someone can act on.
Use this for your own project. Required sections are completeness checks, not automated diagnosis. Do not include passwords, private records or secrets.
Your reproducible report
Your investigation notebook.
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