const fs = require('fs');
const path = require('path');
/**
* Build Cursor MCP function call objects for preview (dry-run).
*/
function buildCreateCall(filePath, content) {
return {
name: 'create_file',
arguments: {
path: filePath,
content: content
}
};
}
function buildEditCall(filePath, content) {
return {
name: 'edit_file',
arguments: {
path: filePath,
content: content
}
};
}
function sanitizeAndResolve(filePath) {
const posix = path.posix;
let normalized = posix.normalize(filePath);
if (posix.isAbsolute(normalized)) throw new Error('Absolute paths are not allowed');
if (normalized.includes('..')) throw new Error('Parent directory (..) segments are not allowed');
if (normalized.startsWith('./')) normalized = normalized.slice(2);
const projectRoot = path.resolve(process.env.PROJECT_ROOT || process.env.WRITE_ROOT || process.cwd());
const resolved = path.resolve(projectRoot, normalized);
if (!(resolved === projectRoot || resolved.startsWith(projectRoot + path.sep))) {
throw new Error('Resolved path is outside the project root');
}
return { normalized, resolved };
}
/**
* createFile writes to disk only when allowWrite=true. Otherwise returns a
* Cursor MCP `create_file` call object for user approval.
*/
function createFile(filePath, content, options = {}) {
const { allowWrite = false } = options;
const { normalized, resolved } = sanitizeAndResolve(filePath);
if (!allowWrite) return buildCreateCall(normalized, content);
// perform actual write
const dir = path.dirname(resolved);
fs.mkdirSync(dir, { recursive: true });
fs.writeFileSync(resolved, content, 'utf8');
return { ok: true, path: normalized };
}
function editFile(filePath, content, options = {}) {
const { allowWrite = false } = options;
const { normalized, resolved } = sanitizeAndResolve(filePath);
if (!allowWrite) return buildEditCall(normalized, content);
const dir = path.dirname(resolved);
fs.mkdirSync(dir, { recursive: true });
fs.writeFileSync(resolved, content, 'utf8');
return { ok: true, path: normalized };
}
module.exports = { buildCreateCall, buildEditCall, createFile, editFile };
