agentsqripts/lib/performance/ast/astPromiseLoopDetector.js

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

/**
 * @file AST-based promise in loop detector
 * @description Detects promise creation in loops using AST analysis
 */

const { parseToAST, isInsideLoop, getNodeLine, getNodeSource, walk } = require('./astParser');
const { PERFORMANCE_PATTERNS } = require('../performancePatterns');

/**
 * Detect promise creation in loops using AST
 * @param {string} content - File content
 * @param {string} filePath - File path
 * @returns {Array} Array of promise in loop issues
 */
function detectPromiseInLoopsAST(content, filePath) {
  const issues = [];
  const ast = parseToAST(content, filePath);
  
  if (!ast) return [];
  
  const pattern = PERFORMANCE_PATTERNS['promise_in_loop'];
  
  // Track if we're already using Promise.all or similar
  const promiseAllUsage = new Set();
  
  walk.simple(ast, {
    CallExpression(node) {
      // Check for Promise.all, Promise.allSettled, etc.
      if (node.callee.type === 'MemberExpression' &&
          node.callee.object.name === 'Promise' &&
          ['all', 'allSettled', 'race'].includes(node.callee.property.name)) {
        // Mark this location as using Promise.all
        promiseAllUsage.add(getNodeLine(node));
      }
    }
  });
  
  // Find promise creation patterns
  walk.simple(ast, {
    NewExpression(node) {
      // new Promise(...)
      if (node.callee.name === 'Promise') {
        checkPromiseInLoop(node);
      }
    },
    
    CallExpression(node) {
      // Promise.resolve/reject
      if (node.callee.type === 'MemberExpression' &&
          node.callee.object.name === 'Promise' &&
          ['resolve', 'reject'].includes(node.callee.property.name)) {
        checkPromiseInLoop(node);
      }
      
      // fetch() calls
      if (node.callee.name === 'fetch') {
        checkPromiseInLoop(node);
      }
      
      // axios calls
      if (node.callee.type === 'MemberExpression' &&
          node.callee.object.name === 'axios' &&
          ['get', 'post', 'put', 'delete', 'patch', 'request'].includes(node.callee.property.name)) {
        checkPromiseInLoop(node);
      }
      
      // .then() chains
      if (node.callee.type === 'MemberExpression' &&
          node.callee.property.name === 'then') {
        checkPromiseInLoop(node);
      }
    }
  });
  
  function checkPromiseInLoop(node) {
    const loop = isInsideLoop(ast, node);
    if (!loop) return;
    
    const line = getNodeLine(node);
    
    // Check if this line is near a Promise.all usage
    const hasPromiseAll = Array.from(promiseAllUsage).some(
      promiseAllLine => Math.abs(promiseAllLine - line) <= 5
    );
    
    if (!hasPromiseAll) {
      const loopType = getLoopType(loop);
      const promiseType = getPromiseType(node);
      
      issues.push({
        type: 'promise_in_loop',
        severity: pattern.severity,
        category: pattern.category,
        location: `${filePath}:${line}`,
        line: line,
        code: getNodeSource(content, node).trim(),
        loopType: loopType,
        promiseType: promiseType,
        description: `Creating ${promiseType} in ${loopType} can cause memory and performance issues`,
        summary: `${promiseType} creation inside ${loopType}`,
        recommendation: 'Collect promises in array and use Promise.all() for concurrent execution',
        effort: pattern.effort,
        impact: pattern.impact,
        estimatedSavings: '30-50% memory and performance improvement'
      });
    }
  }
  
  function getLoopType(loopNode) {
    if (loopNode.type === 'ForStatement') return 'for loop';
    if (loopNode.type === 'WhileStatement') return 'while loop';
    if (loopNode.type === 'DoWhileStatement') return 'do-while loop';
    if (loopNode.type === 'ForInStatement') return 'for-in loop';
    if (loopNode.type === 'ForOfStatement') return 'for-of loop';
    if (loopNode.type === 'CallExpression') {
      return `${loopNode.callee.property.name} loop`;
    }
    return 'loop';
  }
  
  function getPromiseType(node) {
    if (node.type === 'NewExpression' && node.callee.name === 'Promise') {
      return 'new Promise';
    }
    if (node.type === 'CallExpression') {
      if (node.callee.type === 'MemberExpression') {
        if (node.callee.object.name === 'Promise') {
          return `Promise.${node.callee.property.name}`;
        }
        if (node.callee.object.name === 'axios') {
          return `axios.${node.callee.property.name}`;
        }
        if (node.callee.property.name === 'then') {
          return 'promise chain';
        }
      }
      if (node.callee.name === 'fetch') {
        return 'fetch (use axios instead)';
      }
    }
    return 'promise';
  }
  
  return issues;
}

module.exports = {
  detectPromiseInLoopsAST
};