From 42657e9204caeb89609d38cd10e0a92d30d134d7 Mon Sep 17 00:00:00 2001
From: Maximiliano Salvatti <40447063+msalvatti@users.noreply.github.com>
Date: Tue, 4 Aug 2026 07:33:45 -0300
Subject: [PATCH] fix(decorators): let the application own the reflect-metadata
 polyfill
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Four decorators carried `import 'reflect-metadata'`. None of the other eight
`@bymax-one` libraries does — the polyfill belongs to the application, which loads
it once in `main.ts`, and NestJS itself pulls it in: importing `@nestjs/common`
alone takes `Reflect.defineMetadata` from `undefined` to `function`.

Carrying it here also contradicted this package's own `"sideEffects": false`. That
flag says no module in the package has a side effect, and an import whose entire
purpose is its side effect is exactly one. Bundlers happen not to drop it — the
decision is made by the imported package's flag, and `reflect-metadata` declares
none — but a manifest should not assert something the code disproves.

The measurable cost was in a consumer's bundle: with the import present, esbuild
inlines the polyfill, taking a minimal bundle from 53 KB to 95 KB even when the
application already loaded it.

Specs keep their own `import 'reflect-metadata'`: a test file is its own entry
point and has no application to load it.
---
 src/server/decorators/on-queue-event.decorator.ts  |  1 -
 src/server/decorators/on-worker-event.decorator.ts | 10 +---------
 src/server/decorators/process.decorator.ts         |  5 +----
 src/server/decorators/processor.decorator.ts       |  1 -
 4 files changed, 2 insertions(+), 15 deletions(-)

diff --git a/src/server/decorators/on-queue-event.decorator.ts b/src/server/decorators/on-queue-event.decorator.ts
index d16ea27..3d4b7c6 100644
--- a/src/server/decorators/on-queue-event.decorator.ts
+++ b/src/server/decorators/on-queue-event.decorator.ts
@@ -8,7 +8,6 @@
  * @layer server/decorators
  */
 
-import 'reflect-metadata'
 import type { QueueEventListenerMetadata } from '../interfaces/processor-metadata.interface'
 import { QUEUE_EVENT_LISTENERS_METADATA_KEY } from './metadata-keys.constants'
 
diff --git a/src/server/decorators/on-worker-event.decorator.ts b/src/server/decorators/on-worker-event.decorator.ts
index d9087bd..2ca0cf2 100644
--- a/src/server/decorators/on-worker-event.decorator.ts
+++ b/src/server/decorators/on-worker-event.decorator.ts
@@ -7,7 +7,6 @@
  * @layer server/decorators
  */
 
-import 'reflect-metadata'
 import type { QueueEventListenerMetadata } from '../interfaces/processor-metadata.interface'
 import { WORKER_EVENT_LISTENERS_METADATA_KEY } from './metadata-keys.constants'
 
@@ -20,14 +19,7 @@ import { WORKER_EVENT_LISTENERS_METADATA_KEY } from './metadata-keys.constants'
  * @see https://docs.bullmq.io/guide/workers/worker-events
  */
 export type WorkerEventName =
-  | 'completed'
-  | 'failed'
-  | 'progress'
-  | 'active'
-  | 'stalled'
-  | 'closing'
-  | 'closed'
-  | 'error'
+  'completed' | 'failed' | 'progress' | 'active' | 'stalled' | 'closing' | 'closed' | 'error'
 
 /**
  * Marks a method as a worker-local event listener for the given event. The
diff --git a/src/server/decorators/process.decorator.ts b/src/server/decorators/process.decorator.ts
index 1854b5d..e7cb19b 100644
--- a/src/server/decorators/process.decorator.ts
+++ b/src/server/decorators/process.decorator.ts
@@ -6,7 +6,6 @@
  * @layer server/decorators
  */
 
-import 'reflect-metadata'
 import type { ProcessHandlerMetadata } from '../interfaces/processor-metadata.interface'
 import { PROCESS_HANDLERS_METADATA_KEY } from './metadata-keys.constants'
 
@@ -38,9 +37,7 @@ export function Process(jobName?: string): MethodDecorator {
     const existing = (Reflect.getOwnMetadata(PROCESS_HANDLERS_METADATA_KEY, target.constructor) ??
       []) as ProcessHandlerMetadata[]
     const entry: ProcessHandlerMetadata =
-      jobName !== undefined
-        ? { jobName, methodKey: propertyKey }
-        : { methodKey: propertyKey }
+      jobName !== undefined ? { jobName, methodKey: propertyKey } : { methodKey: propertyKey }
     Reflect.defineMetadata(PROCESS_HANDLERS_METADATA_KEY, [...existing, entry], target.constructor)
   }
 }
diff --git a/src/server/decorators/processor.decorator.ts b/src/server/decorators/processor.decorator.ts
index 1d4c637..bd0c51f 100644
--- a/src/server/decorators/processor.decorator.ts
+++ b/src/server/decorators/processor.decorator.ts
@@ -5,7 +5,6 @@
  * @layer server/decorators
  */
 
-import 'reflect-metadata'
 import { DEFAULT_WORKER_CONCURRENCY } from '../constants/default-options'
 import type { ProcessorMetadata } from '../interfaces/processor-metadata.interface'
 import type { WorkerOptions } from '../interfaces/worker-options.interface'