agentsqripts/lib/static-bugs/unreachableCodeChecker.js

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

/**
 * @file Unreachable code checker
 * @description Checks for unreachable code patterns
 */

/**
 * Check for unreachable code
 * @param {string} content - File content
 * @param {string} filePath - File path
 * @returns {Array} Unreachable code issues
 */
function checkUnreachableCode(content, filePath) {
  const issues = [];
  const lines = content.split('\n');
  
  lines.forEach((line, index) => {
    const trimmed = line.trim();
    
    if (trimmed.startsWith('return') && index < lines.length - 1) {
      // Check if this is a multi-line return statement
      let isMultiLineReturn = false;
      let checkIndex = index;
      
      // Look for continuation of return statement
      while (checkIndex < lines.length - 1) {
        const currentLine = lines[checkIndex].trim();
        const nextLine = lines[checkIndex + 1];
        const nextTrimmed = nextLine ? nextLine.trim() : '';
        
        // If current line ends with operators or open parentheses, it continues
        if (currentLine.endsWith('||') || currentLine.endsWith('&&') || 
            currentLine.endsWith(',') || currentLine.endsWith('(') ||
            currentLine.endsWith('+') || currentLine.endsWith('-') ||
            !currentLine.endsWith(';')) {
          isMultiLineReturn = true;
          checkIndex++;
          
          // If next line is closing brace or semicolon, stop
          if (nextTrimmed.startsWith('}') || nextTrimmed === ';') {
            break;
          }
        } else {
          // Return statement is complete
          break;
        }
      }
      
      // Only flag as unreachable if there's code after complete return
      if (!isMultiLineReturn) {
        const nextLine = lines[index + 1];
        if (nextLine && nextLine.trim() && !nextLine.trim().startsWith('}')) {
          issues.push({
            type: 'unreachable_code',
            line: index + 2,
            severity: 'MEDIUM',
            category: 'Logic Error',
            description: 'Code after return statement is unreachable',
            summary: 'Unreachable code detected',
            location: `${filePath}:${index + 2}`,
            recommendation: 'Remove unreachable code or restructure control flow',
            effort: 1,
            impact: 'low',
            file: filePath
          });
        }
      }
    }
  });
  
  return issues;
}

module.exports = {
  checkUnreachableCode
};