fix: move the Windows C++ redistributable warning so it is only shown…

… if there is an actual access violation (cloudflare#6508)

Replaces cloudflare#6471, which was too verbose.

Fixes cloudflare#6170

.changeset/tasty-mayflies-march.md

@@ -0,0 +1,9 @@
+---
+"wrangler": patch
+---
+
+fix: move the Windows C++ redistributable warning so it is only shown if there is an actual access violation
+
+Replaces #6471, which was too verbose.
+
+Fixes #6170

.vscode/settings.json

@@ -30,6 +30,7 @@
 		"PKCE",
 		"Positionals",
 		"qwik",
+		"Redistributable",
 		"reinitialise",
 		"scandir",
 		"selfsigned",

fixtures/worker-app/src/index.js

@@ -5,6 +5,10 @@ import { logErrors } from "./log";
 
 console.log("startup log");
 
+console.error(
+	"*** Received structured exception #0xc0000005: access violation; stack: 7ffe71872f57 7ff7834b643b 7ff7834b643b"
+);
+
 /** @param {Uint8Array} array */
 function hexEncode(array) {
 	return Array.from(array)

fixtures/worker-app/tests/index.test.ts

@@ -44,6 +44,13 @@ describe("'wrangler dev' correctly renders pages", () => {
 		expect(output).toContain("startup log");
 		expect(output).toContain("request log");
 
+		if (process.platform === "win32") {
+			// Check that the Windows warning is shown for the fake access violation error
+			expect(output).toContain(
+				"On Windows, this may be caused by an outdated Microsoft Visual C++ Redistributable library."
+			);
+		}
+
 		// check host on request in the Worker is as expected
 		expect(output).toContain(`host' => 'prod.example.org`);
 

packages/wrangler/src/dev/local.tsx

@@ -228,15 +228,6 @@ function useLocalWorker(props: LocalProps) {
 					"code" in error &&
 					(error as { code: string }).code === "ERR_RUNTIME_FAILURE"
 				) {
-					// In the past we have seen Access Violation errors on Windows, which may be caused by an outdated
-					// version of the Microsoft Visual C++ Redistributable.
-					// See https://github.com/cloudflare/workers-sdk/issues/6170#issuecomment-2245209918
-					if (process.platform === "win32") {
-						logger.error(
-							"Check that you have the latest Microsoft Visual C++ Redistributable library installed.\n" +
-								"See https://learn.microsoft.com/en-us/cpp/windows/latest-supported-vc-redist."
-						);
-					}
 					// Don't log a full verbose stack-trace when Miniflare 3's workerd instance fails to start.
 					// workerd will log its own errors, and our stack trace won't have any useful information.
 					logger.error(String(error));

packages/wrangler/src/dev/miniflare.ts

@@ -728,6 +728,9 @@ export function handleRuntimeStdio(stdout: Readable, stderr: Readable) {
 		isCodeMovedWarning(chunk: string) {
 			return /CODE_MOVED for unknown code block/.test(chunk);
 		},
+		isAccessViolation(chunk: string) {
+			return chunk.includes("access violation;");
+		},
 	};
 
 	stdout.on("data", (chunk: Buffer | string) => {
@@ -752,7 +755,7 @@ export function handleRuntimeStdio(stdout: Readable, stderr: Readable) {
 			logger.warn(chunk);
 		}
 
-		// anything not exlicitly handled above should be logged as info (via stdout)
+		// anything not explicitly handled above should be logged as info (via stdout)
 		else {
 			logger.info(getSourceMappedString(chunk));
 		}
@@ -775,15 +778,33 @@ export function handleRuntimeStdio(stdout: Readable, stderr: Readable) {
 					`Address already in use (${address}). Please check that you are not already running a server on this address or specify a different port with --port.`
 				);
 
-				// even though we've intercepted the chunk and logged a better error to stderr
-				// fallthrough to log the original chunk to the debug log file for observability
+				// Log the original error to the debug logs.
+				logger.debug(chunk);
+			}
+			// In the past we have seen Access Violation errors on Windows, which may be caused by an outdated
+			// version of the Windows OS or the Microsoft Visual C++ Redistributable.
+			// See https://github.com/cloudflare/workers-sdk/issues/6170#issuecomment-2245209918
+			else if (classifiers.isAccessViolation(chunk)) {
+				let error = "There was an access violation in the runtime.";
+				if (process.platform === "win32") {
+					error +=
+						"\nOn Windows, this may be caused by an outdated Microsoft Visual C++ Redistributable library.\n" +
+						"Check that you have the latest version installed.\n" +
+						"See https://learn.microsoft.com/en-us/cpp/windows/latest-supported-vc-redist.";
+				}
+				logger.error(error);
+
+				// Log the original error to the debug logs.
+				logger.debug(chunk);
 			}
 
 			// IGNORABLE:
 			// anything else not handled above is considered ignorable
 			// so send it to the debug logs which are discarded unless
 			// the user explicitly sets a logLevel indicating they care
-			logger.debug(chunk);
+			else {
+				logger.debug(chunk);
+			}
 		}
 
 		// known case: warnings are not errors, log them as such
@@ -796,7 +817,7 @@ export function handleRuntimeStdio(stdout: Readable, stderr: Readable) {
 			// ignore entirely, don't even send it to the debug log file
 		}
 
-		// anything not exlicitly handled above should be logged as an error (via stderr)
+		// anything not explicitly handled above should be logged as an error (via stderr)
 		else {
 			logger.error(getSourceMappedString(chunk));
 		}