Multi-Hoster-Upload/lib/log-rotation.js
Administrator d9c3a00016 test(log): extract log-rotation into testable module + 10 unit tests
The fileuploader.log rotation introduced in 3.3.2 lived inline in
main.js — fine for the runtime path, but it required electron's `app`
to even reach the function under test. Pull the rotation logic into
lib/log-rotation.js (pure fs/path, no electron deps) and cover it
properly:

- ENOENT (file missing) → no-op
- Below cap → no-op
- Over cap → live → .1, returns true
- Existing backups shift up: .1 → .2, .2 → .3
- At maxBackups limit → oldest dropped, others shift, live becomes .1
- Idempotent: rotating twice keeps the chain consistent
- maxBackups=1: never grows past .1
- Invalid maxBytes (0/negative/NaN) → safe no-op
- Provided debug callback receives a "rotated" message
- File without extension still rotates correctly

main.js now imports `maybeRotateLogFile` and calls it directly. 97/97
tests pass.
2026-04-28 05:10:53 +02:00

53 lines
1.9 KiB
JavaScript

// Generic numbered-backup log rotation. Used by the upload log + can be
// reused by other long-lived log files (debug log, account-rotation log).
//
// Behaviour:
// - File missing → no-op, returns false.
// - File ≤ maxBytes → no-op, returns false.
// - File > maxBytes → drop oldest .N backup, shift .K → .K+1, rename live
// file to .1, return true. Caller (or the next append) creates a fresh
// primary on demand.
//
// Errors are reported via `log` (e.g. debugLog) but never thrown — rotation
// is best-effort; the caller's append happens anyway.
const fs = require('fs');
const path = require('path');
function maybeRotateLogFile(filePath, maxBytes, maxBackups = 3, log = () => {}) {
if (!filePath || !Number.isFinite(maxBytes) || maxBytes <= 0) return false;
let size = 0;
try {
const st = fs.statSync(filePath);
size = st.size;
} catch (err) {
// ENOENT is normal — nothing to rotate yet.
if (err && err.code !== 'ENOENT') {
log(`logRotation: stat ${filePath} failed: ${err.message}`);
}
return false;
}
if (size <= maxBytes) return false;
const ext = path.extname(filePath);
const base = filePath.slice(0, filePath.length - ext.length);
// Drop the oldest backup if it exists, then shift each numbered backup up
// one slot. Errors are ignored: missing intermediate backups are normal,
// failed renames just mean we'll rotate again next time.
try { fs.unlinkSync(`${base}.${maxBackups}${ext}`); } catch {}
for (let i = maxBackups - 1; i >= 1; i--) {
try { fs.renameSync(`${base}.${i}${ext}`, `${base}.${i + 1}${ext}`); } catch {}
}
try {
fs.renameSync(filePath, `${base}.1${ext}`);
log(`logRotation: rotated ${filePath} (${(size / 1024 / 1024).toFixed(1)} MB) → ${base}.1${ext}`);
return true;
} catch (err) {
log(`logRotation: rename ${filePath}${base}.1${ext} failed: ${err.message}`);
return false;
}
}
module.exports = { maybeRotateLogFile };