Deny passing `Buffer` columns to SQLite JSON helpers.

[igalklebanov]

Hey 👋

SQLite errors with SqliteError: JSON cannot hold BLOB values when a binary typed column or literal are passed to JSON functions.

The usual workaround is to omit such values from the data passed to these functions, or to cast the binary values to text or similar.

Currently, our SQLite JSON helpers allow passing such values. They shouldn't.

It started happening in SQLite version 3.45.0 (Jan 15th 2024) with the introduction of JSONB.

For Kysely users, this started with better-sqlite3@9.4.0 (Feb 1st 2024).

The minimum Node.js version we support is 20. It is supported in better-sqlite3@^8.4.0 || ^9.0.0. Its EOL comes in April 30th, 2026.

So:

Breaking change for folks using better-sqlite3@<9.4.0.
Bug fix for folks using better-sqlite3@^9.4.0.

[hwisu]

Howdy! 👋
I’m interested in helping with #1687, and while digging into it, I wanted to share something I found before attempting a fix.

It looks like two different BLOB-related behaviors might be getting conflated:

1. BLOB as JSON input (known JSON BLOB input bug)

SELECT json(X'7b226e616d65223a2274657374227d');

This had a short regression in 3.45.0, but was restored in 3.45.1+.

2. BLOB as a JSON value (what this issue seems to be about)

SELECT json_object('data', X'DEADBEEF');

From my testing, this has always failed — SQLite JSON doesn’t appear to support BLOB values.

I tested this across 3.42.0, 3.45.0, 3.45.1, and 3.51.2, and the behavior looked consistent in all versions, so it didn’t seem tied to the JSONB changes in 3.45.0.

Based on that, my current understanding is that addressing #1687 may be more of a DX improvement on the TypeScript side rather than a SQLite regression — but I’d really appreciate a sanity check in case I’m misunderstanding something.

Please let me know if I missed anything. Happy to dig further if needed 😄

Repro: https://github.com/hwisu/kysely-blob-json-repro
Ref: https://www.sqlite.org/json1.html#jblobbug

[igalklebanov]

Gemini be trippin' probably.

Still a type-level bug fix.