Mono environment variables

Author: maraf

src/Components/WebAssembly/HotReload/src/wwwroot/Microsoft.DotNet.HotReload.WebAssembly.Browser.lib.module.js

@@ -1,4 +1,14 @@
 export async function onRuntimeConfigLoaded(config) {
+    // If we have 'aspnetcore-browser-refresh', configure mono runtime for HotReload.
+    if (config.debugLevel !== 0 && globalThis.window?.document?.querySelector("script[src*='aspnetcore-browser-refresh']")) {
+        if (!config.environmentVariables["DOTNET_MODIFIABLE_ASSEMBLIES"]) {
+            config.environmentVariables["DOTNET_MODIFIABLE_ASSEMBLIES"] = "debug";
+        }
+        if (!config.environmentVariables["__ASPNETCORE_BROWSER_TOOLS"]) {
+            config.environmentVariables["__ASPNETCORE_BROWSER_TOOLS"] = "true";
+        }
+    }
+
     // Disable HotReload built-into the Blazor WebAssembly runtime
     config.environmentVariables["__BLAZOR_WEBASSEMBLY_LEGACY_HOTRELOAD"] = "false";
 }