[wasm][test] install handlers for unhandled exceptions on browser

src/mono/wasm/runtime/run-outer.ts

@@ -57,6 +57,35 @@ class HostBuilder implements DotnetHostBuilder {
         }
     }
 
+    // internal
+    withExitOnUnhandledError(): DotnetHostBuilder {
+        try {
+            // it seems that emscripten already does the right thing for NodeJs and that there is no good solution for V8 shell.
+            if (ENVIRONMENT_IS_WEB) {
+                window.addEventListener("unhandledrejection", (event: PromiseRejectionEvent) => {
+                    event.preventDefault();
+                    try {
+                        mono_exit(1, event.reason);
+                    } catch (err) {
+                        // no not re-throw from the unhandledrejection handler
+                    }
+                });
+                window.addEventListener("error", (event: ErrorEvent) => {
+                    event.preventDefault();
+                    try {
+                        mono_exit(1, event.error);
+                    } catch (err) {
+                        // no not re-throw from the error handler
+                    }
+                });
+            }
+            return this;
+        } catch (err) {
+            mono_exit(1, err);
+            throw err;
+        }
+    }
+
     // internal
     withAsyncFlushOnExit(): DotnetHostBuilder {
         try {

src/mono/wasm/runtime/run.ts

@@ -1,7 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-import { ENVIRONMENT_IS_WEB, INTERNAL, Module, runtimeHelpers } from "./imports";
+import { ENVIRONMENT_IS_WEB, Module, runtimeHelpers } from "./imports";
 import { mono_wasm_wait_for_debugger } from "./debug";
 import { abort_startup, mono_wasm_set_main_args } from "./startup";
 import cwraps from "./cwraps";
@@ -108,12 +108,14 @@ async function flush_node_streams() {
 function set_exit_code_and_quit_now(exit_code: number, reason?: any): void {
     if (runtimeHelpers.ExitStatus) {
         if (reason && !(reason instanceof runtimeHelpers.ExitStatus)) {
-            if (reason instanceof Error)
-                Module.printErr(INTERNAL.mono_wasm_stringify_as_error_with_stack(reason));
-            else if (typeof reason == "string")
-                Module.printErr(reason);
-            else
-                Module.printErr(JSON.stringify(reason));
+            if (!runtimeHelpers.config.logExitCode) {
+                if (reason instanceof Error)
+                    Module.printErr(mono_wasm_stringify_as_error_with_stack(reason));
+                else if (typeof reason == "string")
+                    Module.printErr(reason);
+                else
+                    Module.printErr(JSON.stringify(reason));
+            }
         }
         else {
             reason = new runtimeHelpers.ExitStatus(exit_code);

src/mono/wasm/test-main.js

@@ -259,14 +259,15 @@ async function run() {
             .withVirtualWorkingDirectory(runArgs.workingDirectory)
             .withEnvironmentVariables(runArgs.environmentVariables)
             .withDiagnosticTracing(runArgs.diagnosticTracing)
+            .withExitOnUnhandledError()
             .withExitCodeLogging()
             .withElementOnExit();
 
         if (is_node) {
             dotnet
                 .withEnvironmentVariable("NodeJSPlatform", process.platform)
                 .withAsyncFlushOnExit();
-            
+
             const modulesToLoad = runArgs.environmentVariables["NPM_MODULES"];
             if (modulesToLoad) {
                 dotnet.withModuleConfig({