feat: handle fs.truncate() using a file descriptor depreciation #122
Description
Description
Since fs.truncate() and fs.truncateSync() with file descriptors are deprecated (DEP0081) and have reached End-of-Life status, we should provide a codemod to replace them.
- The codemod should replace all instances of
fs.truncate(fd, ...)withfs.ftruncate(fd, ...)when the first argument is a file descriptor. - The codemod should replace all instances of
fs.truncateSync(fd, ...)withfs.ftruncateSync(fd, ...)when the first argument is a file descriptor. - The codemod should update import/require statements to include
ftruncateandftruncateSyncwhen needed. - The codemod should NOT replace
fs.truncate(path, ...)calls where the first argument is a file path string.
Additional Information
Note that fs.truncate() and fs.truncateSync() with file descriptors are deprecated in favor of fs.ftruncate() and fs.ftruncateSync(). The behavior is identical, but the new functions have clearer naming to indicate they work with file descriptors. Using fs.truncate() with file paths (strings) remains valid and supported.
Detection Strategy
The codemod should identify file descriptor usage by analyzing the context:
- If the first argument to truncate/truncateSync is a variable that was assigned from fs.open/fs.openSync calls
- If the first argument is a numeric literal or variable with numeric type hints
- If the call is within a callback from fs.open() where the second parameter is typically the file descriptor
Examples
Case 1: Destructured import with callback version
Before:
const { truncate, open, close } = require('node:fs');
open('file.txt', 'w', (err, fd) => {
if (err) throw err;
truncate(fd, 10, (err) => {
if (err) throw err;
close(fd, () => {});
});
});After:
const { ftruncate, open, close } = require('node:fs');
open('file.txt', 'w', (err, fd) => {
if (err) throw err;
ftruncate(fd, 10, (err) => {
if (err) throw err;
close(fd, () => {});
});
});Case 2: Namespace import with sync version
Before:
const fs = require('node:fs');
const fd = fs.openSync('file.txt', 'w');
try {
fs.truncateSync(fd, 10);
} finally {
fs.closeSync(fd);
}After:
const fs = require('node:fs');
const fd = fs.openSync('file.txt', 'w');
try {
fs.ftruncateSync(fd, 10);
} finally {
fs.closeSync(fd);
}Case 3: Mixed usage (file descriptor and file path)
Before:
const { truncate, truncateSync, open, openSync, close, closeSync } = require('node:fs');
// This should be replaced (file descriptor)
const fd = openSync('file.txt', 'w');
truncateSync(fd, 10);
closeSync(fd);
// This should NOT be replaced (file path)
truncate('other.txt', 5, (err) => {
if (err) throw err;
});After:
const { truncate, ftruncateSync, open, openSync, close, closeSync } = require('node:fs');
// This should be replaced (file descriptor)
const fd = openSync('file.txt', 'w');
ftruncateSync(fd, 10);
closeSync(fd);
// This should NOT be replaced (file path)
truncate('other.txt', 5, (err) => {
if (err) throw err;
});Case 4: ESM import
Before:
import { truncate, open, close } from 'node:fs';
open('file.txt', 'w', (err, fd) => {
if (err) throw err;
truncate(fd, 10, (err) => {
if (err) throw err;
close(fd, () => {});
});
});After:
import { ftruncate, open, close } from 'node:fs';
open('file.txt', 'w', (err, fd) => {
if (err) throw err;
ftruncate(fd, 10, (err) => {
if (err) throw err;
close(fd, () => {});
});
});