[wrangler] Add deprecation warning for queue delivery_delay

.changeset/deprecate-queue-delivery-delay.md

@@ -0,0 +1,11 @@
+---
+"wrangler": patch
+"@cloudflare/workers-utils": patch
+---
+
+Add deprecation warning for `delivery_delay` in queue producer bindings
+
+The `delivery_delay` setting in `[[queues.producers]]` was silently having no effect since 2024.
+This change adds a deprecation warning when the setting is used, informing users that queue-level
+settings should be configured using `wrangler queues update` instead. The setting will be removed
+in a future version.

packages/workers-utils/src/config/validation.ts

@@ -3527,6 +3527,18 @@ const validateQueueBinding: ValidatorFn = (diagnostics, field, value) => {
 		}
 	}
 
+	// Warn if delivery_delay is set, as it is deprecated and has no effect
+	if (
+		hasProperty(value, "delivery_delay") &&
+		value.delivery_delay !== undefined
+	) {
+		diagnostics.warnings.push(
+			`The "delivery_delay" field in "${field}" is deprecated and has no effect. ` +
+				`Queue-level settings should be configured using "wrangler queues update" instead. ` +
+				`This setting will be removed in a future version.`
+		);
+	}
+
 	if (!isRemoteValid(value, field, diagnostics)) {
 		isValid = false;
 	}

packages/workers-utils/tests/config/validation/normalize-and-validate-config.test.ts

@@ -3334,6 +3334,37 @@ describe("normalizeAndValidateConfig()", () => {
 			  - \\"queues.consumers[3]\\" should, optionally, have a number \\"max_concurrency\\" field but got {\\"queue\\":\\"myQueue\\",\\"max_batch_size\\":\\"3\\",\\"max_batch_timeout\\":null,\\"max_retries\\":\\"hello\\",\\"dead_letter_queue\\":5,\\"max_concurrency\\":\\"hello\\"}."
 		`);
 			});
+
+			it("should warn if delivery_delay is set on a queue producer", () => {
+				const { config, diagnostics } = normalizeAndValidateConfig(
+					{
+						queues: {
+							producers: [
+								{ binding: "QUEUE_BINDING_1", queue: "queue1" },
+								{
+									binding: "QUEUE_BINDING_2",
+									queue: "queue2",
+									delivery_delay: 60,
+								},
+							],
+						},
+					} as unknown as RawConfig,
+					undefined,
+					undefined,
+					{ env: undefined }
+				);
+
+				expect(config.queues.producers).toHaveLength(2);
+				expect(config.queues.producers?.[1]).toMatchObject({
+					delivery_delay: 60,
+				});
+				expect(diagnostics.hasErrors()).toBe(false);
+				expect(diagnostics.hasWarnings()).toBe(true);
+				expect(diagnostics.renderWarnings()).toMatchInlineSnapshot(`
+					"Processing wrangler configuration:
+					  - The \\"delivery_delay\\" field in \\"queues.producers[1]\\" is deprecated and has no effect. Queue-level settings should be configured using \\"wrangler queues update\\" instead. This setting will be removed in a future version."
+				`);
+			});
 		});
 
 		describe("[r2_buckets]", () => {