The top 5 JavaScript issues in all our codebases

on YouTube ↗35m

" summary

Scans of hundreds of millions of lines across thousands of repos produce a ranked list: most common JavaScript issues are unused assignments, == coercion, commented‑out code, widespread use of var instead of let/const, and functions with cognitive complexity ≥15; tooling used includes Sona Cloud scans, SonarLint and an ESLint SonarJS plugin; a revealjs confetti plugin is built to demo refactoring and it works; findings emphasize specific fixes, frequency, and measurable thresholds rather than vague advice.

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" chapters (13)

1. 0:00Introduction
2. 3:07Clean code in JavaScript
3. 7:18Unused variable assignments
4. 10:05Double equals coercion
5. 12:11Commented-out code
6. 13:54TypeScript issues overview
7. 15:19React bind/arrow function props
8. 16:21Unnecessary imports
9. 17:46VAR vs const/let
10. 19:36Cognitive complexity in functions
11. 31:21Tools for JavaScript issues
12. 34:11Refactoring for maintainability
13. 35:13Closing remarks

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