hcengineering/platform · error

Invalid key

Error message

Invalid key

What it means

Error thrown by PreviewCache.put when the supplied cache key is an empty string. Empty keys cannot map to a stable file path under the cache directory, so the write is rejected early before touching the filesystem.

Source

Thrown at pods/preview/src/cache.ts:140

            this.ctx.error('Failed to remove cache file', { path: entry, error: err })
          }
        })

        return Promise.all(promises)
      },
      { cacheCount: this.cache.size, cacheSize: this.cache.calculatedSize, gcCount: disposed.length }
    )
  }

  get (key: string): PreviewFile | undefined {
    return this.cache.get(key)
  }

  async put (key: string, value: PreviewFile): Promise<PreviewFile> {
    let filePath = normalize(value.filePath)

    if (key.length === 0) {
      throw new Error('Invalid key')
    }

    const { size } = await stat(value.filePath)

    if (!filePath.startsWith(this.cachePath)) {
      try {
        filePath = this.getFilePath(key)
        await mkdir(dirname(filePath), { recursive: true })
        await rename(value.filePath, filePath)
      } catch (err) {
        this.ctx.error('Failed to move file to cache', { filePath, error: err })
        throw err
      }
    }

    const entry = { ...value, filePath, size }
    this.cache.set(key, entry)

View on GitHub (pinned to 63e28dc964)

Solutions

1. Validate the key before calling put: if (!key) throw or skip the cache write
2. Fix upstream key derivation so it always yields a non-empty digest (check what is being hashed)
3. Guard put() at the call site and fall back to a no-cache path
4. Log the input that produced the empty key to trace the derivation bug

Example fix

// before
await cache.put(key, previewFile) // key === ''
// after
if (!key) {
  console.warn('skip cache: empty key for', sourceUrl)
} else {
  await cache.put(key, previewFile)
}

if (typeof key !== 'string' || key.length === 0) throw new Error('cache key required')

try {
  await cache.put(key, value)
} catch (e) {
  if (e.message === 'Invalid key') return null // bypass cache
  throw e
}

When it happens

Trigger: Calling cache.put('', file) — typically because the hash/key derivation returned '' (e.g. hashing an empty URL, a failed digest, or a variable defaulting to empty before the call).

Common situations: Hash function silently returning empty on invalid input, using an unescaped/trimmed URL field that ends up empty, or wiring bugs where the key variable was never populated.

Related errors

• Key cannot be empty
• Failed to load server config
• getDisplayMedia not supported
• No screen access granted
• Message id is required

AI-assisted analysis of hcengineering/platform@63e28dc964 (2026-08-29). Data as JSON: /api/errors/6dc914949ff7521b. Report an issue: GitHub.