Run worker for module exports if queue consumer specified

Previously, queue consumers would never be triggered when running
using the Miniflare test environments. This change ensures the
worker script is executed, adding the `queue` event listener if
present.

Author: mrbbot

packages/queues/src/plugin.ts

@@ -122,6 +122,9 @@ export class QueuesPlugin
         binding.queueName
       );
     }
-    return { bindings };
+
+    const requiresModuleExports =
+      this.queueConsumers !== undefined && this.queueConsumers.length > 0;
+    return { bindings, requiresModuleExports };
   }
 }

packages/queues/test/plugin.spec.ts

@@ -146,3 +146,18 @@ test("QueuesPlugin: setup: includes queues in bindings", async (t) => {
   t.true(result.bindings?.QUEUE1 instanceof WorkerQueue);
   t.true(result.bindings?.QUEUE2 instanceof WorkerQueue);
 });
+
+test("QueuesPlugin: setup: requires module exports if consuming", async (t) => {
+  const queueBroker = new QueueBroker();
+  const pluginCtx: PluginContext = { ...ctx, queueBroker };
+  let plugin = new QueuesPlugin(pluginCtx, {
+    queueBindings: [{ name: "QUEUE", queueName: "queue" }],
+  });
+  let result = await plugin.setup(factory);
+  t.false(result.requiresModuleExports);
+  plugin = new QueuesPlugin(pluginCtx, {
+    queueConsumers: ["queue"],
+  });
+  result = await plugin.setup(factory);
+  t.true(result.requiresModuleExports);
+});