Harden: reject file uploads over 25 MiB on the client - #214
Merged
Baskarayelu merged 1 commit intoAug 28, 2026
Merged
Baskarayelu merged 1 commit into
Baskarayelu merged 1 commit into
Conversation
No file-size guard existed anywhere in this app. Add validateFileUpload(file), rejecting anything over 25 MiB before it's read into memory or sent to the server -- a client-side UX/DoS guard, not a substitute for the server enforcing its own limit on the actual request.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
No file-size guard existed anywhere in the codebase -- an oversized upload (a multi-gigabyte accidental drag-drop, for example) had no client-side rejection before being read into memory or sent to the server.
Change
`lib/validation/fileUpload.ts`: `validateFileUpload(file)` returns `{ ok, error }` (never throws), rejecting anything over `MAX_UPLOAD_BYTES` (25 MiB) with a human-readable size in the message. This is a client-side UX/DoS-prevention guard, not a substitute for the server enforcing its own limit on the actual request.
Tests
`lib/validation/fileUpload.test.ts`: accepts at the exact limit, accepts a small file, rejects one byte over, and rejects a much larger file with the expected message text.
`npx vitest run lib/validation/fileUpload.test.ts`: 4 passed. `npx tsc --noEmit` / `npx eslint` on changed files: clean.
Related to #109