How to use this developer tool
- Paste or upload JavaScript.
- Choose an analysis profile.
- Set the maximum preferred function length.
- Run the inspection and review severity-tagged findings.
#112 · JavaScript Developer Tool
JavaScript Inspector
Inspect JavaScript structure, risky patterns, nesting, async usage, DOM access, and maintainability signals in the browser without executing or uploading the source.
Developer Input
Browser-based source processinglines
Ad space
What this developer tool does
The inspector performs static, heuristic checks for risky APIs, loose equality, debugging statements, deep nesting, long functions, imports, exports, classes, promises, and timers.
Lexical masking → structure extraction → risk-rule checks → complexity estimate → prioritized report.
Findings are static review signals, not proof of runtime failure. Each warning should be reviewed in context.
Example
Input:
function run(value){
if(value == 1){
console.log(value);
eval("value + 1");
}
}Expected use: Run the selected mode and review the generated output and statistics.Tips for better output
- Treat heuristic warnings as review prompts.
- Security focus assigns greater weight to eval and dynamic code.
- Long functions are estimated from declaration ranges.
- No source code is executed.
FAQ
How can I inspect JavaScript code quality online?
Paste the source and run Balanced analysis to receive structure, risk, and maintainability findings.
How do I find risky JavaScript functions?
Enable Detect risky APIs to identify eval, new Function, document.write, string timers, and related patterns.
How can I detect eval usage in JavaScript?
The inspector reports eval calls with line numbers and high-risk severity.
How do I measure JavaScript function complexity?
The report estimates complexity from control-flow operators and maximum nesting depth.
How can I find deeply nested JavaScript code?
The inspector calculates approximate brace nesting and flags unusually deep sections.
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Supported analysis and output
| Module | Purpose |
|---|---|
| Input | Local browser processing |
| Analysis | Tool-specific lexical and structural logic |
| Output | Copy and download ready |
| Privacy | No upload or server execution |