fix(cloudflare/workers): enable strictExecutionOrder to prevent cross-chunk TDZ at startup

[john-royal]

Closes #749

Rolldown's chunking can split top-level initializer modules (e.g. Drizzle pgTable schemas) into a chunk that forms a cycle with the entry chunk (worker.js -> auth-*.js -> worker.js when drizzle-orm stays in the entry). ESM evaluation then runs the schema chunk before drizzle's class bindings initialize, and the script fails Cloudflare startup validation:

ScriptStartupError: Uncaught ReferenceError: Cannot access 'a' before initialization
  at auth-BFaahPAe.js:1:110

The fix enables rolldown's strictExecutionOrder on WorkerBundle's output options, which wraps cross-chunk modules so evaluation follows ESM semantics regardless of chunk boundaries:

 const outputOptions: rolldown.OutputOptions = {
   format: "esm",
   sourcemap: "hidden",
   minify: true,
   keepNames: true,
+  strictExecutionOrder: true,
   dir: `.alchemy/bundles/${options.id}`,
 };

Lambda's codeSplitting: false approach is not safe for Workers: Worker bundles rely on chunks to keep dynamically-imported Node/Bun-only modules from evaluating eagerly in workerd. strictExecutionOrder keeps the chunks and fixes only the evaluation order. This makes the user-side advancedChunks grouping workaround from the issue unnecessary.

WorkerProps.build now also forwards rolldown output overrides (merged over WorkerBundle's defaults) plus preserveEntrySignatures — the issue's other ask, chunking was previously uncontrollable per Worker:

Cloudflare.Worker("Api", {
  main,
  build: {
    preserveEntrySignatures: "allow-extension",
    output: {
      codeSplitting: {
        groups: [{ name: "auth", test: "packages/(schema|auth)/", includeDependenciesRecursively: false }],
      },
    },
  },
});

Group test patterns are strings (compiled to regexes by rolldown) — RegExp literals don't survive props serialization.

Repro / tests

test/Cloudflare/Workers/DrizzleSchemaChunks.test.ts + fixtures/drizzle-schema-chunks/ mirror the reporter's monorepo shape (db schema/* + auth package tables with top-level pgTable(...) cross-imports). The test deploys a stack whose Cloudflare.Worker forces the cyclic chunk layout via build options. Cloudflare's startup validation runs on exactly those chunks at upload, so the deploy is itself the regression assertion; the test also verifies the cyclic layout on disk (auth-*.js importing ./worker.js back) and fetches the worker.

The cycle is essential: an acyclic split (e.g. drizzle in its own chunk imported by the schema chunk) evaluates correctly under plain import order and never triggers the bug. Verified live that flipping strictExecutionOrder: false on the stack restores the exact ScriptStartupError above.

Passes live, plus WorkerBundle.test.ts (CJS-require conversion + deploy integration) and RandomEnvLocal.test.ts (local workerd path) are green with the new default.

[alchemy-version-bot]

Install the packages built from this commit:

alchemy

bun add alchemy@https://pkg.ing/alchemy/40bf479

@alchemy.run/better-auth

bun add @alchemy.run/better-auth@https://pkg.ing/@alchemy.run/better-auth/40bf479

@alchemy.run/pr-package

bun add @alchemy.run/pr-package@https://pkg.ing/@alchemy.run/pr-package/40bf479