[Blazor] Pass environment to runtime config only when defined

src/Components/Web.JS/src/Platform/Mono/MonoPlatform.ts

@@ -138,9 +138,12 @@ function prepareRuntimeConfig(options: Partial<WebAssemblyStartOptions>, onConfi
   const config: MonoConfig = {
     maxParallelDownloads: 1000000, // disable throttling parallel downloads
     enableDownloadRetry: false, // disable retry downloads
-    applicationEnvironment: options.environment,
   };
 
+  if (options.environment) {
+    config.applicationEnvironment = options.environment;
+  }
+
   const onConfigLoaded = async (loadedConfig: MonoConfig) => {
     if (!loadedConfig.environmentVariables) {
       loadedConfig.environmentVariables = {};

src/Components/test/E2ETest/Tests/WebAssemblyConfigurationTest.cs

@@ -40,13 +40,13 @@ public void WebAssemblyConfiguration_Works()
         if (_serverFixture.TestTrimmedOrMultithreadingApps)
         {
             // Verify that the environment gets detected as 'Production'.
-            Browser.Equal("Production", () => _appElement.FindElement(By.Id("environment")).Text);
+            Browser.Equal("Staging", () => _appElement.FindElement(By.Id("environment")).Text);
 
             // Verify values overriden by an environment specific 'appsettings.$(Environment).json are read
-            Assert.Equal("Prod key2-value", _appElement.FindElement(By.Id("key2")).Text);
+            Assert.Equal("Staging key2-value", _appElement.FindElement(By.Id("key2")).Text);
 
             // Lastly for sanity, make sure values specified in an environment specific 'appsettings.$(Environment).json are read
-            Assert.Equal("Prod key3-value", _appElement.FindElement(By.Id("key3")).Text);
+            Assert.Equal("Staging key3-value", _appElement.FindElement(By.Id("key3")).Text);
         }
         else
         {

src/Components/test/testassets/BasicTestApp/BasicTestApp.csproj

@@ -13,12 +13,13 @@
     <BlazorWebAssemblyLoadAllGlobalizationData>true</BlazorWebAssemblyLoadAllGlobalizationData>
 
     <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
-    
+
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(TestTrimmedOrMultithreadingApps)' == 'true'">
     <!-- Avoid spending time brotli compression publish output.-->
     <_BlazorBrotliCompressionLevel>NoCompression</_BlazorBrotliCompressionLevel>
+    <WasmApplicationEnvironmentName>Staging</WasmApplicationEnvironmentName>
   </PropertyGroup>
 
   <ItemGroup>

src/Components/test/testassets/BasicTestApp/wwwroot/appsettings.Staging.json

@@ -0,0 +1,4 @@
+{
+  "key2": "Staging key2-value",
+  "key3": "Staging key3-value"
+}