agentsqripts/lib/performance/react/detectStateUpdates.js

Comprehensive static code analysis toolkit for identifying technical debt, security vulnerabilities, performance issues, and code quality problems

/**
 * @file Detect problematic state updates
 * @description Single responsibility: Identify performance issues with React state updates
 */

const { iterateLines } = require('../../utils/patternDetector');

/**
 * Detect problematic state updates
 */
function detectStateUpdates(lines, filePath) {
  const issues = [];
  
  iterateLines(lines, (line, lineNumber, trimmed, i) => {
    
    // setState in loops
    if (/for\s*\(|\.forEach\s*\(|\.map\s*\(|while\s*\(/.test(trimmed)) {
      for (let j = i + 1; j < Math.min(i + 10, lines.length); j++) {
        const innerLine = lines[j].trim();
        if (/set\w+\s*\(|setState\s*\(/.test(innerLine)) {
          issues.push({
            type: 'state_update_in_loop',
            severity: 'HIGH',
            category: 'React',
            location: `${filePath}:${j + 1}`,
            line: j + 1,
            code: innerLine,
            description: 'State update in loop causes multiple re-renders',
            summary: 'State updates inside loop',
            recommendation: 'Batch state updates or collect changes and update once',
            effort: 2,
            impact: 'Reduces number of re-renders significantly',
            estimatedSavings: '70-90% re-render reduction'
          });
          break;
        }
      }
    }
    
    // Multiple setState calls
    if (/set\w+\s*\(|setState\s*\(/.test(trimmed)) {
      let setStateCount = 1;
      for (let j = i + 1; j < Math.min(i + 5, lines.length); j++) {
        if (/set\w+\s*\(|setState\s*\(/.test(lines[j])) {
          setStateCount++;
        }
      }
      
      if (setStateCount >= 3) {
        issues.push({
          type: 'multiple_state_updates',
          severity: 'MEDIUM',
          category: 'React',
          location: `${filePath}:${lineNumber}`,
          line: lineNumber,
          code: trimmed,
          description: `Multiple state updates (${setStateCount}) in sequence cause multiple re-renders`,
          summary: 'Multiple consecutive state updates',
          recommendation: 'Combine state updates or use useReducer for complex state',
          effort: 2,
          impact: 'Reduces re-renders',
          estimatedSavings: '50-70% re-render reduction'
        });
      }
    }
  });
  
  return issues;
}

module.exports = detectStateUpdates;