Revert "[browser] Remove check for user agent when attaching debugger"

src/libraries/System.Runtime.InteropServices.JavaScript/tests/System.Runtime.InteropServices.JavaScript.UnitTests/System/Runtime/InteropServices/JavaScript/JSImportTest.cs

@@ -238,7 +238,7 @@ public unsafe void CreateFunctionString()
         [Fact]
         public unsafe void CreateFunctionInternal()
         {
-            Func<bool> internals = Utils.CreateFunctionBool("return true");
+            Func<bool> internals = Utils.CreateFunctionBool("return INTERNAL.mono_wasm_runtime_is_ready");
             Assert.True(internals());
         }
 

src/mono/browser/runtime/lazyLoading.ts

@@ -53,7 +53,7 @@ export async function loadLazyAssembly (assemblyNameToLoad: string): Promise<boo
 
     let pdbNameToLoad = assemblyNameWithoutExtension + ".pdb";
     let shouldLoadPdb = false;
-    if (loaderHelpers.config.debugLevel != 0) {
+    if (loaderHelpers.config.debugLevel != 0 && loaderHelpers.isDebuggingSupported()) {
         shouldLoadPdb = Object.prototype.hasOwnProperty.call(lazyAssemblies, pdbNameToLoad);
         if (loaderHelpers.config.resources!.fingerprinting) {
             const map = loaderHelpers.config.resources!.fingerprinting;

src/mono/browser/runtime/loader/assets.ts

@@ -350,7 +350,7 @@ export function prepareAssets () {
         }
 
 
-        if (config.debugLevel != 0) {
+        if (config.debugLevel != 0 && loaderHelpers.isDebuggingSupported()) {
             if (resources.corePdb) {
                 for (const name in resources.corePdb) {
                     addAsset({

src/mono/browser/runtime/loader/config.ts

@@ -278,6 +278,15 @@ export async function mono_wasm_load_config (module: DotnetModuleInternal): Prom
     }
 }
 
+export function isDebuggingSupported (): boolean {
+    // Copied from blazor MonoDebugger.ts/attachDebuggerHotkey
+    if (!globalThis.navigator) {
+        return false;
+    }
+
+    return loaderHelpers.isChromium || loaderHelpers.isFirefox;
+}
+
 async function loadBootConfig (module: DotnetModuleInternal): Promise<void> {
     const defaultConfigSrc = loaderHelpers.locateFile(module.configSrc!);
 

src/mono/browser/runtime/loader/globals.ts

@@ -15,7 +15,7 @@ import { assertIsControllablePromise, createPromiseController, getPromiseControl
 import { mono_download_assets, resolve_single_asset_path, retrieve_asset_download } from "./assets";
 import { mono_log_error, set_thread_prefix, setup_proxy_console } from "./logging";
 import { invokeLibraryInitializers } from "./libraryInitializers";
-import { deep_merge_config } from "./config";
+import { deep_merge_config, isDebuggingSupported } from "./config";
 import { logDownloadStatsToConsole, purgeUnusedCacheEntriesAsync } from "./assetsCache";
 
 // if we are the first script loaded in the web worker, we are expected to become the sidecar
@@ -128,6 +128,7 @@ export function setLoaderGlobals (
 
         retrieve_asset_download,
         invokeLibraryInitializers,
+        isDebuggingSupported,
 
         // from wasm-feature-detect npm package
         exceptions,

src/mono/browser/runtime/startup.ts

@@ -328,9 +328,7 @@ async function onRuntimeInitializedAsync (userOnRuntimeInitialized: () => void)
 
         runtimeList.registerRuntime(exportedRuntimeAPI);
 
-        if (loaderHelpers.config.debugLevel !== 0 && !runtimeHelpers.mono_wasm_runtime_is_ready) {
-            mono_wasm_runtime_ready();
-        }
+        if (!runtimeHelpers.mono_wasm_runtime_is_ready) mono_wasm_runtime_ready();
 
         if (loaderHelpers.config.debugLevel !== 0 && loaderHelpers.config.cacheBootResources) {
             loaderHelpers.logDownloadStatsToConsole();
@@ -602,6 +600,9 @@ export function mono_wasm_load_runtime (): void {
                 debugLevel = 0 + debugLevel;
             }
         }
+        if (!loaderHelpers.isDebuggingSupported() || !runtimeHelpers.config.resources!.pdb) {
+            debugLevel = 0;
+        }
         cwraps.mono_wasm_load_runtime(debugLevel);
         endMeasure(mark, MeasuredBlock.loadRuntime);
 

src/mono/browser/runtime/types/internal.ts

@@ -172,6 +172,7 @@ export type LoaderHelpers = {
     invokeLibraryInitializers: (functionName: string, args: any[]) => Promise<void>,
     libraryInitializers?: { scriptName: string, exports: any }[];
 
+    isDebuggingSupported(): boolean,
     isChromium: boolean,
     isFirefox: boolean