refactor(wrangler): share pending metrics requests across all dispatchers

Move the requests tracking from per-dispatcher instance to module-level
scope so that all dispatchers share the same Set of pending requests.
This ensures all metrics requests are awaited before Wrangler exits,
regardless of which dispatcher created them.

- Add module-level pendingRequests Set with auto-cleanup via .finally()
- Export waitForAllMetricsDispatches() to await all pending requests
- Remove the per-dispatcher requests getter

Author: petebacondarwin

packages/wrangler/src/__tests__/metrics.test.ts

@@ -18,7 +18,10 @@ import {
 	readMetricsConfig,
 	writeMetricsConfig,
 } from "../metrics/metrics-config";
-import { getMetricsDispatcher } from "../metrics/metrics-dispatcher";
+import {
+	getMetricsDispatcher,
+	waitForAllMetricsDispatches,
+} from "../metrics/metrics-dispatcher";
 import { sniffUserAgent } from "../package-manager";
 import { mockConsoleMethods } from "./helpers/mock-console";
 import { useMockIsTTY } from "./helpers/mock-istty";
@@ -79,7 +82,8 @@ describe("metrics", () => {
 			});
 		});
 
-		afterEach(() => {
+		afterEach(async () => {
+			await waitForAllMetricsDispatches();
 			vi.useRealTimers();
 		});
 
@@ -101,7 +105,7 @@ describe("metrics", () => {
 					sendMetrics: true,
 				});
 				dispatcher.sendAdhocEvent("some-event", { a: 1, b: 2 });
-				await Promise.all(dispatcher.requests);
+				await waitForAllMetricsDispatches();
 				expect(requests.count).toBe(1);
 				expect(std.debug).toMatchInlineSnapshot(
 					`"Metrics dispatcher: Posting data {\\"deviceId\\":\\"f82b1f46-eb7b-4154-aa9f-ce95f23b2288\\",\\"event\\":\\"some-event\\",\\"timestamp\\":1733961600000,\\"properties\\":{\\"category\\":\\"Workers\\",\\"wranglerVersion\\":\\"1.2.3\\",\\"wranglerMajorVersion\\":1,\\"wranglerMinorVersion\\":2,\\"wranglerPatchVersion\\":3,\\"os\\":\\"foo:bar\\",\\"agent\\":null,\\"a\\":1,\\"b\\":2}}"`
@@ -118,7 +122,7 @@ describe("metrics", () => {
 					sendMetrics: true,
 				});
 				dispatcher.sendAdhocEvent("version-test");
-				await Promise.all(dispatcher.requests);
+				await waitForAllMetricsDispatches();
 				expect(requests.count).toBe(1);
 				expect(std.debug).toContain('"wranglerVersion":"1.2.3"');
 				expect(std.debug).toContain('"wranglerMajorVersion":1');
@@ -152,7 +156,7 @@ describe("metrics", () => {
 					sendMetrics: true,
 				});
 				dispatcher.sendAdhocEvent("some-event", { a: 1, b: 2 });
-				await Promise.all(dispatcher.requests);
+				await waitForAllMetricsDispatches();
 
 				expect(std.debug).toMatchInlineSnapshot(`
 					"Metrics dispatcher: Posting data {\\"deviceId\\":\\"f82b1f46-eb7b-4154-aa9f-ce95f23b2288\\",\\"event\\":\\"some-event\\",\\"timestamp\\":1733961600000,\\"properties\\":{\\"category\\":\\"Workers\\",\\"wranglerVersion\\":\\"1.2.3\\",\\"wranglerMajorVersion\\":1,\\"wranglerMinorVersion\\":2,\\"wranglerPatchVersion\\":3,\\"os\\":\\"foo:bar\\",\\"agent\\":null,\\"a\\":1,\\"b\\":2}}
@@ -194,7 +198,7 @@ describe("metrics", () => {
 					sendMetrics: true,
 				});
 				dispatcher.sendAdhocEvent("some-event", { a: 1 });
-				await Promise.all(dispatcher.requests);
+				await waitForAllMetricsDispatches();
 
 				expect(requests.count).toBe(1);
 				expect(std.debug).toContain('"agent":"claude-code"');
@@ -210,34 +214,13 @@ describe("metrics", () => {
 					sendMetrics: true,
 				});
 				dispatcher.sendAdhocEvent("some-event", { a: 1 });
-				await Promise.all(dispatcher.requests);
+				await waitForAllMetricsDispatches();
 
 				expect(requests.count).toBe(1);
 				expect(std.debug).toContain('"agent":null');
 			});
 		});
 
-		it("should keep track of all requests made", async () => {
-			const requests = mockMetricRequest();
-			const dispatcher = getMetricsDispatcher({
-				sendMetrics: true,
-			});
-
-			dispatcher.sendAdhocEvent("some-event", { a: 1, b: 2 });
-			expect(dispatcher.requests.length).toBe(1);
-
-			expect(requests.count).toBe(0);
-			await Promise.allSettled(dispatcher.requests);
-			expect(requests.count).toBe(1);
-
-			dispatcher.sendAdhocEvent("another-event", { c: 3, d: 4 });
-			expect(dispatcher.requests.length).toBe(2);
-
-			expect(requests.count).toBe(1);
-			await Promise.allSettled(dispatcher.requests);
-			expect(requests.count).toBe(2);
-		});
-
 		describe("sendCommandEvent()", () => {
 			const reused = {
 				wranglerVersion: "1.2.3",

packages/wrangler/src/index.ts

@@ -91,7 +91,7 @@ import {
 	kvNamespaceRenameCommand,
 } from "./kv";
 import { logger, LOGGER_LEVELS } from "./logger";
-import { getMetricsDispatcher } from "./metrics";
+import { getMetricsDispatcher, waitForAllMetricsDispatches } from "./metrics";
 import {
 	metricsAlias,
 	telemetryDisableCommand,
@@ -346,6 +346,7 @@ import { workflowsInstancesTerminateAllCommand } from "./workflows/commands/inst
 import { workflowsListCommand } from "./workflows/commands/list";
 import { workflowsTriggerCommand } from "./workflows/commands/trigger";
 import { printWranglerBanner } from "./wrangler-banner";
+import type { ReadConfigCommandArgs } from "./config";
 import type { LoggerLevel } from "./logger";
 import type { CommonYargsArgv, SubHelp } from "./yargs-types";
 
@@ -1782,15 +1783,15 @@ export async function main(argv: string[]): Promise<void> {
 
 	const startTime = Date.now();
 	let command: string | undefined;
-	let metricsArgs: Record<string, unknown> | undefined;
+	let configArgs: ReadConfigCommandArgs = {};
 	let dispatcher: ReturnType<typeof getMetricsDispatcher> | undefined;
 
 	// Register middleware to capture command info for fallback telemetry
 	const wranglerWithTelemetry = wranglerWithMiddleware.middleware((args) => {
 		// Capture command and args for potential fallback telemetry
 		// (used when yargs validation errors occur before handler runs)
 		command = `wrangler ${args._.join(" ")}`;
-		metricsArgs = args;
+		configArgs = args;
 
 		try {
 			const { rawConfig, configPath } = experimental_readRawConfig(args);
@@ -1816,25 +1817,25 @@ export async function main(argv: string[]): Promise<void> {
 		// Check if this is a CommandHandledError (telemetry already sent by handler)
 		if (e instanceof CommandHandledError) {
 			// Unwrap and handle the original error
-			await handleError(e.originalError, metricsArgs ?? {}, argv);
+			await handleError(e.originalError, configArgs, argv);
 			throw e.originalError;
 		}
 
 		// Fallback telemetry for errors that occurred before handler ran
 		// (e.g., yargs validation errors like unknown commands or invalid arguments)
-		if (dispatcher && command && metricsArgs) {
+		if (dispatcher && command) {
 			const durationMs = Date.now() - startTime;
 
 			// Send "started" event (since handler never got to send it)
 			dispatcher.sendCommandEvent("wrangler command started", {
 				command,
-				args: metricsArgs,
+				args: configArgs,
 			});
 
 			// Send "errored" event
 			dispatcher.sendCommandEvent("wrangler command errored", {
 				command,
-				args: metricsArgs,
+				args: configArgs,
 				durationMs,
 				durationSeconds: durationMs / 1000,
 				durationMinutes: durationMs / 1000 / 60,
@@ -1846,7 +1847,7 @@ export async function main(argv: string[]): Promise<void> {
 			});
 		}
 
-		await handleError(e, metricsArgs ?? {}, argv);
+		await handleError(e, configArgs, argv);
 		throw e;
 	} finally {
 		try {
@@ -1866,7 +1867,7 @@ export async function main(argv: string[]): Promise<void> {
 
 			// Wait for any pending telemetry requests to complete (with timeout)
 			await Promise.race([
-				Promise.allSettled(dispatcher?.requests ?? []),
+				waitForAllMetricsDispatches(),
 				setTimeout(1000, undefined, { ref: false }),
 			]);
 		} catch (e) {

packages/wrangler/src/metrics/index.ts

@@ -1,4 +1,7 @@
-export { getMetricsDispatcher } from "./metrics-dispatcher";
+export {
+	getMetricsDispatcher,
+	waitForAllMetricsDispatches,
+} from "./metrics-dispatcher";
 export { getMetricsConfig } from "./metrics-config";
 export * from "./send-event";
 export { getMetricsUsageHeaders } from "./metrics-usage-headers";

packages/wrangler/src/metrics/metrics-dispatcher.ts

@@ -30,6 +30,18 @@ import type { CommonEventProperties, Events } from "./types";
 
 const SPARROW_URL = "https://sparrow.cloudflare.com";
 
+// Module-level Set to track all pending requests across all dispatchers.
+// Promises are automatically removed from this Set once they settle.
+const pendingRequests = new Set<Promise<void>>();
+
+/**
+ * Wait for all pending metrics requests to complete.
+ * This should be called before the process exits to ensure all metrics are sent.
+ */
+export function waitForAllMetricsDispatches(): Promise<void> {
+	return Promise.allSettled(pendingRequests).then(() => {});
+}
+
 /**
  * A list of all the command args that can be included in the event.
  *
@@ -58,7 +70,6 @@ export function getMetricsDispatcher(options: MetricsConfigOptions) {
 	// The SPARROW_SOURCE_KEY will be provided at build time through esbuild's `define` option
 	// No events will be sent if the env `SPARROW_SOURCE_KEY` is not provided and the value will be set to an empty string instead.
 	const SPARROW_SOURCE_KEY = process.env.SPARROW_SOURCE_KEY ?? "";
-	const requests: Array<Promise<void>> = [];
 	const wranglerVersion = getWranglerVersion();
 	const [wranglerMajorVersion, wranglerMinorVersion, wranglerPatchVersion] =
 		wranglerVersion.split(".").map((v) => parseInt(v, 10));
@@ -181,10 +192,6 @@ export function getMetricsDispatcher(options: MetricsConfigOptions) {
 				logger.debug("Error sending metrics event", err);
 			}
 		},
-
-		get requests() {
-			return requests;
-		},
 	};
 
 	function dispatch(event: { name: string; properties: Properties }) {
@@ -241,9 +248,12 @@ export function getMetricsDispatcher(options: MetricsConfigOptions) {
 					"Metrics dispatcher: Failed to send request:",
 					(e as Error).message
 				);
+			})
+			.finally(() => {
+				pendingRequests.delete(request);
 			});
 
-		requests.push(request);
+		pendingRequests.add(request);
 	}
 
 	function printMetricsBanner() {