[karthickeyan-dev]

Closes #756

Problem

Better Auth applies onUpdate and defaultValue itself on its own writes, but the Drizzle columns in .void/better-auth-schema.ts had neither. Writes that go directly through Drizzle missed them: db.update() on an auth table left updatedAt unchanged, and a row inserted without banned stored null instead of false.

Changes

createColumnDefinition now emits:

• .$onUpdate(() => new Date()) for Better Auth's built-in updatedAt fields, unless overridden through additional fields or a plugin
• .$defaultFn(() => <literal>) for string, number and boolean defaults, on optional fields too

"emailVerified": integer("emailVerified", { mode: "boolean" }).notNull().$defaultFn(() => false),
"updatedAt": integer("updatedAt", { mode: "timestamp_ms" }).notNull().$onUpdate(() => new Date()),
"banned": integer("banned", { mode: "boolean" }).$defaultFn(() => false),

Both are runtime-only Drizzle modifiers, so existing apps need no migration. resolveFixedDefault still returns only required fields' defaults, so migrationSchema is unchanged.

Custom update callbacks remain handled by Better Auth and are omitted from the generated Drizzle columns.

Function defaults such as createdAt's () => new Date() are left out, as are date and JSON literals, matching the existing exclusions.

Drizzle also runs $onUpdate on insert when the value is omitted, and treats the column as optional in insert types. For updatedAt this fills in the current time rather than failing the NOT NULL constraint.

Verification

• New cases in packages/void/test/unit/auth-drizzle.test.ts cover update hooks in all three dialects, required and optional literal defaults, excluded function/date/JSON defaults, and unchanged migration metadata.
• Ran the generated schemas through real Drizzle and drizzle-kit: snapshots are identical with and without the modifiers on SQLite, PostgreSQL and MySQL; the generated code typechecks in all three; on SQLite a direct update sets updatedAt and an insert gets the literal defaults.
• vp run check passes.
• vp test run locally: 16,453 passed, 8 failed.
  • 5 are api-webhooks timeouts that also fail on main in a full run on this machine.
  • 3 are in cf-build-output (timeout) and plugin-cloudflare-v2 (inspector port EADDRINUSE). These did not fail on main, but passed 3 of 3 runs in isolation on this branch and do not reference the auth generator.

🤖 Generated with Claude Code

[cpojer]

Thanks!