The top 5 JavaScript issues in all our codebases
summary
Data from thousands of projects on SonarCloud and SonarQube shows five concrete problems: the single biggest issue is widespread use of var instead of let or const, many functions exceed the SonarJS cognitive complexity threshold (cognitive complexity >15), frequent unused assignments clutter codebases, loose equality (==/!=) causes bugs and performance hits, and checked‑in commented‑out code remains. SonarQube Community Edition and SonarLint are cited as the actual tools used to detect these patterns and the talk gives concrete refactoring moves (extract functions, replace var, prefer ===) tied to those detections.
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chapters (8)
- 0:00Top JavaScript issues
- 6:51Unused assignments
- 10:03Double vs triple equals
- 13:58Commented out code dangers
- 16:25Avoid let and var
- 20:01Cognitive complexity
- 32:44Summary and call to action
- 33:07Q&A
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