Scope loadModule default-export unwrap to drizzle config imports

loadModule used to apply `mod?.default ?? mod` in all three branches
(Bun/Deno, jiti, ESM Node), so every caller silently received the
default export when present. Only drizzleConfigFromFile actually needs
that — drizzle.config.ts uses `export default defineConfig(...)` —
while the 11 schema-loading call sites in cli/commands/studio.ts and
dialects/*/drizzle.ts iterate `Object.entries(mod)` to find PgTable /
MySqlTable / Relations values, where the unwrap masks bugs and silently
rescues non-canonical `export default { tables }` schemas.

Add an explicit `{ defaultExport }` options flag, default false. All
three branches now return `defaultExport ? (mod?.default ?? mod) : mod`.
drizzleConfigFromFile passes `{ defaultExport: true }`; the schema-
loading call sites are unchanged and now receive the raw namespace.

Behavior change: schema files using `export default { users, posts }`
stop working — must switch to named exports (`export const users =
pgTable(...)`), the documented drizzle pattern.

- pnpm exec tsc --noEmit -p tsconfig.json → 0
- vitest run tests/other/ → 376/376

Author: dankochetov

drizzle-kit/src/cli/commands/utils.ts

@@ -945,7 +945,7 @@ export const drizzleConfigFromFile = async (
 
 	if (!isExport) humanLog(`Reading config file '${path}'`);
 
-	const content = await loadModule<any>(path);
+	const content = await loadModule<any>(path, { defaultExport: true });
 
 	// --- get response and then check by each dialect independently
 	const res = configCommonSchema.safeParse(content);

drizzle-kit/src/utils/utils-node.ts

@@ -428,11 +428,12 @@ const isDeno = typeof (globalThis as any).Deno !== 'undefined';
 
 export const loadModule = async <T = unknown>(
 	modulePath: string,
+	{ defaultExport = false }: { defaultExport?: boolean } = {},
 ): Promise<T> => {
 	if (isBun || isDeno) {
 		const fileUrl = pathToFileURL(modulePath).href;
 		const mod = await import(fileUrl);
-		return mod.default ?? mod;
+		return defaultExport ? (mod?.default ?? mod) : mod;
 	}
 
 	const [major, minor] = process.versions.node.split('.').map(Number);
@@ -466,9 +467,9 @@ export const loadModule = async <T = unknown>(
 			requireCache: false,
 		});
 		const mod = await jiti.import<any>(absoluteModulePath);
-		return mod?.default ?? mod;
+		return defaultExport ? (mod?.default ?? mod) : mod;
 	}
 	const fileUrl = pathToFileURL(absoluteModulePath).href;
 	const mod = await import(fileUrl);
-	return mod.default ?? mod;
+	return defaultExport ? (mod?.default ?? mod) : mod;
 };