[browser][wasm] Fix CoreCLR Emscripten out/err override

src/mono/wasm/Wasm.Build.Tests/ModuleConfigTests.cs

@@ -57,7 +57,7 @@ public async Task DownloadProgressFinishes(bool failAssemblyDownload)
         );
     }
 
-    [ConditionalFact(typeof(BuildTestBase), nameof(IsMonoRuntime)), TestCategory("bundler-friendly")]
+    [Fact, TestCategory("bundler-friendly")]
     public async Task OutErrOverrideWorks()
     {
         Configuration config = Configuration.Debug;

src/native/libs/Common/JavaScript/loader/run.ts

@@ -35,6 +35,23 @@ export async function createRuntime(downloadOnly: boolean): Promise<any> {
         const modulesAfterConfigLoadedPromises: [JsAsset, Promise<any>][] = normalizeCollection(resources.modulesAfterConfigLoaded).map((a) => [a, callLibraryInitializerOnRuntimeConfigLoaded(a)]);
         await Promise.all(modulesAfterConfigLoadedPromises.map(([, p]) => p));
 
+        // Wire user-provided out/err overrides to Emscripten's print/printErr.
+        // This must happen before the native module loads so Emscripten picks them up.
+        if (!Module.out) {
+            // eslint-disable-next-line no-console
+            Module.out = console.log.bind(console);
+        }
+        if (!Module.err) {
+            // eslint-disable-next-line no-console
+            Module.err = console.error.bind(console);
+        }
+        if (!Module.print) {
+            Module.print = Module.out;
+        }
+        if (!Module.printErr) {
+            Module.printErr = Module.err;
+        }
+
         // after onConfigLoaded hooks that could install polyfills, our polyfills can be initialized
         await initPolyfills();
 

src/native/libs/Common/JavaScript/types/internal.ts

@@ -46,6 +46,8 @@ export type EmscriptenInternals = {
 export type EmscriptenModuleInternal = EmscriptenModule & DotnetModuleConfig & {
     runtimeKeepalivePush(): void;
     runtimeKeepalivePop(): void;
+    print(message: string): void;
+    printErr(message: string): void;
     instantiateWasm?: InstantiateWasmCallBack;
     onAbort?: (reason: any, extraJson?: string) => void;
     onExit?: (code: number) => void;