agentsqripts/lib/performance/database-patterns/detectors/detectUnoptimizedQueries.js

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

/**
 * @file Detect unoptimized query patterns
 * @description Single responsibility: Identify inefficient database query patterns
 */

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

function detectUnoptimizedQueries(lines, filePath) {
  const issues = [];
  
  iterateLines(lines, (line, lineNumber, trimmed, i) => {
    
    // SELECT * queries
    if (/SELECT\s+\*\s+FROM/i.test(trimmed)) {
      issues.push({
        type: 'select_star_query',
        severity: 'MEDIUM',
        category: 'Database',
        location: `${filePath}:${lineNumber}`,
        line: lineNumber,
        code: trimmed,
        description: 'SELECT * fetches unnecessary columns and impacts performance',
        summary: 'Unoptimized SELECT * query',
        recommendation: 'Specify only needed columns in SELECT clause',
        effort: 1,
        impact: '20-50% query performance improvement',
        estimatedSavings: '20-50% data transfer reduction'
      });
    }
    
    // Queries without WHERE clause in loops
    if (/for\s*\(|\.forEach\s*\(/.test(trimmed)) {
      for (let j = i + 1; j < Math.min(i + 5, lines.length); j++) {
        const innerLine = lines[j].trim();
        if (/SELECT.*FROM(?!.*WHERE)/i.test(innerLine)) {
          issues.push({
            type: 'unfiltered_query_in_loop',
            severity: 'HIGH',
            category: 'Database',
            location: `${filePath}:${j + 1}`,
            line: j + 1,
            code: innerLine,
            description: 'Query without WHERE clause in loop fetches all records',
            summary: 'Unfiltered query in loop',
            recommendation: 'Add appropriate WHERE clause to filter results',
            effort: 2,
            impact: '70-90% query performance improvement',
            estimatedSavings: '70-90% data reduction'
          });
          break;
        }
      }
    }
    
    // Missing pagination
    if (/\.find\s*\(\s*\)\s*$/.test(trimmed) || /SELECT.*FROM(?!.*LIMIT)/i.test(trimmed)) {
      issues.push({
        type: 'missing_pagination',
        severity: 'MEDIUM',
        category: 'Database',
        location: `${filePath}:${lineNumber}`,
        line: lineNumber,
        code: trimmed,
        description: 'Query without pagination may return large datasets',
        summary: 'Query missing pagination',
        recommendation: 'Add LIMIT/OFFSET or use cursor-based pagination',
        effort: 2,
        impact: 'Prevents large dataset issues',
        estimatedSavings: 'controlled memory usage'
      });
    }
  });
  
  return issues;
}

module.exports = detectUnoptimizedQueries;