Fix unprotected JSON.parse in Redis.getObject() crashing viewer stats processing

[lawrence3699]

Description

Noticed while reading through the viewer stats processing code that Redis.getObject() calls JSON.parse() without any error handling. On a self-hosted instance, if a Redis value gets corrupted (partial write during a crash, data from a different PeerTube version, manual Redis intervention), the unhandled parse error propagates up through getLocalVideoViewerByKey() in processViewerStats().

Since getLocalVideoViewerByKey() is called outside the inner try/catch block (line 157, before the transaction at line 164), the exception is caught by the outer catch at line 181 — which exits the entire for loop. This means a single corrupted entry blocks all remaining viewer stats from being persisted to the database.

Minimal reproduction:

// getObject behavior without fix:
JSON.parse('{"lastUpdated": 0, "corrupt')
// => SyntaxError — crashes the whole batch

The same codebase already handles this correctly in server/core/models/server/plugin.ts (lines 209–213):

try {
  return JSON.parse(value)
} catch {
  return value
}

Before: One corrupted Redis viewer stats entry crashes processViewerStats(), preventing all remaining entries from being saved to the database.

After: Corrupted entries are logged, cleaned up from Redis, and skipped. The remaining entries are processed normally.

Changes

• redis.ts: Wrap JSON.parse in getObject() with try/catch, log warning, return null
• video-viewer-stats.ts: Add null check in processViewerStats() loop — log, delete the invalid key, and continue

Related issues

Has this been tested?

• 👍 Verified with a minimal reproduction script that a corrupted JSON value crashes JSON.parse and the fix returns null instead
• 💭 Full integration test would require a running Redis instance; the fix follows the same pattern already validated in plugin.ts

Screenshots

N/A

[Copilot]

Pull request overview

Defensive hardening of viewer stats batch processing so a corrupted Redis entry doesn’t crash processViewerStats() and block persistence of subsequent viewer stats.

Changes:

• Add try/catch around JSON.parse in Redis.getObject() and return null on parse failure.
• Skip and delete invalid viewer stats Redis keys during processViewerStats() when stats cannot be loaded.
• Add warning logs for parse failures / invalid viewer stats entries.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
server/core/lib/stats/shared/video-viewer-stats.ts	Skip/delete invalid viewer stats entries during batch processing to prevent aborting the whole loop.
server/core/lib/redis.ts	Catch JSON.parse failures in getObject() and log/return null instead of throwing.

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[Copilot]

The new invalid-entry path deletes the Redis key outside the per-key try/catch. If deleteLocalVideoViewersKeys throws (Redis connectivity, permission, etc.), it will be caught by the outer catch and abort the entire for loop, reintroducing the “one bad entry stops the batch” behavior. Consider wrapping the delete in its own try/catch (log and continue), or reusing the inner per-key try/catch around the invalid-entry cleanup as well.

Suggested change

	await this.deleteLocalVideoViewersKeys(key)
	try {
	await this.deleteLocalVideoViewersKeys(key)
	} catch (err) {
	logger.error('Cannot delete invalid viewer stats for Redis key %s.', key, { err, ...lTags() })
	}

[Copilot]

stats can now legitimately be null (e.g. parse failure in Redis.getObject()), but it’s still typed as LocalViewerStats here. Updating the return types of getLocalVideoViewerByKey/getLocalVideoViewer (and this local variable) to LocalViewerStats | null would make the null-handling explicit and prevent accidental property access elsewhere without a guard.

Suggested change

	const stats: LocalViewerStats = await this.getLocalVideoViewerByKey(key)
	const stats: LocalViewerStats | null = await this.getLocalVideoViewerByKey(key)

[Copilot]

This new warning log in redis.ts omits the file’s standard lTags() metadata (used by other logs in this module). Adding { err, ...lTags() } (or similar) will keep Redis logs consistently taggable/filterable.

Suggested change

	logger.warn('Cannot parse Redis key %s.', key, { err })
	logger.warn('Cannot parse Redis key %s.', key, { err, ...lTags() })