Function analyzeResponseDifference

background.js:326–427

(originalResponse, modifiedResponse, originalText, modifiedText, settings)

// ============================================================================

async function analyzeResponseDifference(originalResponse, modifiedResponse, originalText, modifiedText, settings) {
  const result = {
    isDifferent: false,
    confidence: 0,
    reasons: [],
    severity: 'low',
    debugIndicators: null,
    headerChanges: [],
  };

  // 1. Status code change detection
  if (settings.detectStatusChanges && originalResponse.status !== modifiedResponse.status) {
    result.reasons.push(`Status changed: ${originalResponse.status} → ${modifiedResponse.status}`);
    result.confidence += 30;

    // Special cases
    if (originalResponse.status === 403 && modifiedResponse.status === 200) {
      result.confidence += 40; // Bypass!
      result.severity = 'critical';
    } else if (modifiedResponse.status >= 500) {
      result.confidence += 20; // Server error triggered
      result.severity = 'high';
    }
  }

  // 2. Header changes
  if (settings.detectHeaderChanges) {
    const originalHeaders = extractInterestingHeaders(originalResponse);
    const modifiedHeaders = extractInterestingHeaders(modifiedResponse);
    result.headerChanges = compareHeaders(originalHeaders, modifiedHeaders);

    if (result.headerChanges.length > 0) {
      result.reasons.push(`Header changes detected: ${result.headerChanges.length}`);
      result.confidence += 15 * result.headerChanges.length;
    }
  }

  // 3. Content length difference
  const lengthDiff = Math.abs(modifiedText.length - originalText.length);
  if (lengthDiff >= settings.minLengthDiff) {
    result.reasons.push(`Content length diff: ${lengthDiff} bytes`);
    result.confidence += Math.min(lengthDiff / 100, 25);
  }

  // 4. Debug indicator detection
  const debugCheck = containsDebugIndicators(modifiedText);
  if (debugCheck.found) {
    result.debugIndicators = debugCheck;
    result.reasons.push(`Debug indicators found: ${debugCheck.level}`);
    result.confidence += debugCheck.level === 'critical' ? 50 : debugCheck.level === 'high' ? 35 : 20;

    if (debugCheck.level === 'critical') result.severity = 'critical';
    else if (debugCheck.level === 'high' && result.severity !== 'critical') result.severity = 'high';
    else if (debugCheck.level === 'medium' && !['critical', 'high'].includes(result.severity)) result.severity = 'medium';
  }

  // 5. Similarity check (after filtering dynamic content)
  let originalFiltered = originalText;