/**
* Sanitize response data to ensure it's safe for JSON serialization
* and doesn't cause parsing issues in the MCP client
*/
export function sanitizeResponse(data: any): any {
if (data === null || data === undefined) {
return data;
}
// Handle strings - ensure they're properly encoded
if (typeof data === 'string') {
// Replace any control characters that might cause issues
return data.replace(/[\x00-\x1F\x7F-\x9F]/g, (char) => {
// Keep newlines, tabs, and carriage returns
if (char === '\n' || char === '\r' || char === '\t') {
return char;
}
// Replace other control characters with their unicode escape
return `\\u${char.charCodeAt(0).toString(16).padStart(4, '0')}`;
});
}
// Handle arrays
if (Array.isArray(data)) {
return data.map(item => sanitizeResponse(item));
}
// Handle objects
if (typeof data === 'object') {
const sanitized: any = {};
for (const [key, value] of Object.entries(data)) {
// Sanitize both keys and values
const sanitizedKey = typeof key === 'string' ? sanitizeResponse(key) : key;
sanitized[sanitizedKey] = sanitizeResponse(value);
}
return sanitized;
}
// Return other types as-is (numbers, booleans, etc.)
return data;
}
/**
* Ensure the response is serializable and within size limits
*/
export function prepareResponse(data: any, maxSize: number = 1000000): any {
// First sanitize the data
const sanitized = sanitizeResponse(data);
// Check size and truncate if needed
const jsonString = JSON.stringify(sanitized);
if (jsonString.length > maxSize) {
// If the response is too large, truncate arrays
if (Array.isArray(sanitized) && sanitized.length > 0) {
const itemSize = jsonString.length / sanitized.length;
const maxItems = Math.floor(maxSize / itemSize) - 1;
return {
data: sanitized.slice(0, maxItems),
truncated: true,
totalCount: sanitized.length,
returnedCount: maxItems
};
}
// For other types, return a truncation message
return {
error: 'Response too large',
truncated: true,
size: jsonString.length,
maxSize
};
}
return sanitized;
}
