drizzle MySqlSelectBase: inherited .then resolves to undefined under Perry (await returns the builder) #2159

Summary

await <drizzle MySqlSelectBase instance> returns the builder object itself instead of resolving to the query result. The instance has .then inherited from drizzle-orm's QueryPromise base class (via 4+ levels of inheritance), but under Perry the property lookup instance.then returns undefined — so await doesn't see a thenable and just unwraps to the original value.

.execute() on the same instance resolves correctly and is the in-fixture workaround. Found while landing the drizzle-mysql fixture for #489.

Repro

In tests/release/packages/drizzle-mysql/entry.ts, replace any line of the form:

const all = await db.select().from(users).execute();

with the idiomatic drizzle form:

const all = await db.select().from(users);

Perry prints count=undefined then SIGBUS'es; Bun (bun --conditions=perry run entry.ts) and Node both print count=2. Verified by inserting diagnostic logs:

sel:  object MySqlSelectBuilder
from: object MySqlSelectBase hasThen= undefined hasExecute= function

So _from.execute resolves to a function but _from.then (inherited from QueryPromise through TypedQueryBuilder → MySqlSelectQueryBuilderBase → MySqlSelectBase) resolves to undefined.

What I tried to minimize (and couldn't)

These all work correctly under Perry — none reproduces the .then === undefined shape:

• 3+ level user-class inheritance with .then defined on the root.
• Same, in a compilePackages .js package.
• Same with static [entityKind] = "..." (computed symbol field) on every class.
• 5-level chain Root → TQB → QBB → SQB → SBase with .then only on Root, static [entityKind] on every level.

Something more specific in drizzle's class graph (likely mixins, decorators, or constructor-injected fields touching then) is the trigger. The drizzle case is reproducible by reverting the .execute() calls in the fixture entry, so this issue's repro lives there.

Impact

Affects every idiomatic drizzle-orm query: await db.select().from(x), await db.update(x).set(...), etc. Currently worked around with explicit .execute() in the drizzle-mysql fixture; fixing this lets users write idiomatic upstream drizzle code unchanged. Likely benefits other thenable libraries with deep mixin-style inheritance.

Related

• Drizzle: 50-line program against real MySQL via @perry/mysql (followup to #488) #489 — drizzle MySQL e2e (where this surfaced; closed via the .execute() workaround).
• await thenable returns the thenable itself instead of calling .then(resolve, reject) #586 — await thenable returns the thenable itself (closed; this is a deeper / drizzle-specific recurrence).