[Blazor] Ensure WebAssembly startup options are initialized just once

src/Components/Web.JS/src/Boot.Web.ts

@@ -26,6 +26,7 @@ import { LogLevel } from './Platform/Logging/Logger';
 import { resolveOptions } from './Platform/Circuits/CircuitStartOptions';
 import { JSInitializer } from './JSInitializers/JSInitializers';
 import { enableFocusOnNavigate } from './Rendering/FocusOnNavigate';
+import { WebAssemblyStartOptions } from './Platform/WebAssemblyStartOptions';
 
 let started = false;
 let rootComponentManager: WebRootComponentManager;
@@ -91,10 +92,11 @@ function onInitialDomContentLoaded(options: Partial<WebStartOptions>) {
   // so we do the same here.
   const initialCircuitOptions = resolveOptions(options?.circuit || {});
   options.circuit = initialCircuitOptions;
+  options.webAssembly = options.webAssembly || ({} as WebAssemblyStartOptions);
   const logger = new ConsoleLogger(initialCircuitOptions.logLevel);
   const initializersPromise = fetchAndInvokeInitializers(options, logger);
   setCircuitOptions(resolveConfiguredOptions(initializersPromise, initialCircuitOptions));
-  setWebAssemblyOptions(resolveConfiguredOptions(initializersPromise, options?.webAssembly || {}));
+  setWebAssemblyOptions(resolveConfiguredOptions(initializersPromise, options.webAssembly));
 
   registerAllComponentDescriptors(document);
   rootComponentManager.onDocumentUpdated();

src/Components/test/E2ETest/ServerRenderingTests/BlazorWebJsInitializersTest.cs

@@ -33,6 +33,11 @@ public void InitializersRunsModernCallbacksByDefaultWhenPresent(bool streaming,
         var url = $"{ServerPathBase}/initializers?streaming={streaming}&wasm={webassembly}&server={server}";
         Navigate(url);
 
+        if (webassembly)
+        {
+            ((IJavaScriptExecutor)Browser).ExecuteScript("sessionStorage.setItem('block-webassembly-settings', 'true')");
+        }
+
         foreach (var callback in expectedInvokedCallbacks)
         {
             Browser.Exists(By.Id(callback));
@@ -56,6 +61,11 @@ public void InitializersRunsClassicInitializersWhenEnabled(bool streaming, bool
         var url = $"{ServerPathBase}/initializers?streaming={streaming}&wasm={webassembly}&server={server}";
         Navigate(url);
 
+        if (webassembly)
+        {
+            ((IJavaScriptExecutor)Browser).ExecuteScript("sessionStorage.setItem('block-webassembly-settings', 'true')");
+        }
+
         foreach (var callback in expectedCallbacks)
         {
             Browser.Exists(By.Id(callback));
@@ -82,12 +92,12 @@ public static TheoryData<bool, bool, bool, string[]> InitializerTestData()
         {
             { false, false, false, ["classic-and-modern-before-web-start", "classic-and-modern-after-web-started","modern-before-web-start", "modern-after-web-started"] },
             { false, false, true, ["classic-and-modern-before-web-start", "classic-and-modern-after-web-started", "classic-and-modern-before-server-start", "classic-and-modern-after-server-started", "classic-and-modern-circuit-opened", "modern-before-web-start", "modern-after-web-started", "modern-before-server-start", "modern-after-server-started", "modern-circuit-opened" ] },
-            { false, true, false, ["classic-and-modern-before-web-start", "classic-and-modern-after-web-started", "classic-and-modern-before-web-assembly-start", "classic-and-modern-after-web-assembly-started", "modern-before-web-start", "modern-after-web-started", "modern-before-web-assembly-start", "modern-after-web-assembly-started"] },
-            { false, true, true, ["classic-and-modern-before-web-start", "classic-and-modern-after-web-started", "classic-and-modern-before-server-start", "classic-and-modern-circuit-opened", "classic-and-modern-after-server-started", "classic-and-modern-before-web-assembly-start", "classic-and-modern-after-web-assembly-started", "modern-before-web-start", "modern-after-web-started", "modern-before-server-start", "modern-circuit-opened", "modern-after-server-started", "modern-before-web-assembly-start", "modern-after-web-assembly-started"] },
+            { false, true, false, ["classic-and-modern-before-web-start", "classic-and-modern-after-web-started", "classic-and-modern-before-web-assembly-start", "classic-and-modern-after-web-assembly-started", "server--classic-and-modern-before-web-assembly-start", "server--classic-and-modern-after-web-assembly-started", "modern-before-web-start", "modern-after-web-started", "modern-before-web-assembly-start", "modern-after-web-assembly-started"] },
+            { false, true, true, ["classic-and-modern-before-web-start", "classic-and-modern-after-web-started", "classic-and-modern-before-server-start", "classic-and-modern-circuit-opened", "classic-and-modern-after-server-started", "classic-and-modern-before-web-assembly-start", "classic-and-modern-after-web-assembly-started", "server--classic-and-modern-before-web-assembly-start", "server--classic-and-modern-after-web-assembly-started", "modern-before-web-start", "modern-after-web-started", "modern-before-server-start", "modern-circuit-opened", "modern-after-server-started", "modern-before-web-assembly-start", "modern-after-web-assembly-started"] },
             { true, false, false, ["classic-and-modern-before-web-start", "classic-and-modern-after-web-started","modern-before-web-start", "modern-after-web-started"] },
             { true, false, true, ["classic-and-modern-before-web-start", "classic-and-modern-after-web-started", "classic-and-modern-before-server-start", "classic-and-modern-after-server-started", "classic-and-modern-circuit-opened", "modern-before-web-start", "modern-after-web-started", "modern-before-server-start", "modern-after-server-started", "modern-circuit-opened" ] },
-            { true, true, false, ["classic-and-modern-before-web-start", "classic-and-modern-after-web-started", "classic-and-modern-before-web-assembly-start", "classic-and-modern-after-web-assembly-started", "modern-before-web-start", "modern-after-web-started", "modern-before-web-assembly-start", "modern-after-web-assembly-started"] },
-            { true, true, true, ["classic-and-modern-before-web-start", "classic-and-modern-after-web-started", "classic-and-modern-before-server-start", "classic-and-modern-circuit-opened", "classic-and-modern-after-server-started", "classic-and-modern-before-web-assembly-start", "classic-and-modern-after-web-assembly-started", "modern-before-web-start", "modern-after-web-started", "modern-before-server-start", "modern-circuit-opened", "modern-after-server-started", "modern-before-web-assembly-start", "modern-after-web-assembly-started"] },
+            { true, true, false, ["classic-and-modern-before-web-start", "classic-and-modern-after-web-started", "classic-and-modern-before-web-assembly-start", "classic-and-modern-after-web-assembly-started", "server--classic-and-modern-before-web-assembly-start", "server--classic-and-modern-after-web-assembly-started", "modern-before-web-start", "modern-after-web-started", "modern-before-web-assembly-start", "modern-after-web-assembly-started"] },
+            { true, true, true, ["classic-and-modern-before-web-start", "classic-and-modern-after-web-started", "classic-and-modern-before-server-start", "classic-and-modern-circuit-opened", "classic-and-modern-after-server-started", "classic-and-modern-before-web-assembly-start", "classic-and-modern-after-web-assembly-started", "server--classic-and-modern-before-web-assembly-start", "server--classic-and-modern-after-web-assembly-started", "modern-before-web-start", "modern-after-web-started", "modern-before-server-start", "modern-circuit-opened", "modern-after-server-started", "modern-before-web-assembly-start", "modern-after-web-assembly-started"] },
         };
 
         return result;

src/Components/test/testassets/BasicTestApp/wwwroot/JSInitializers/ClassicAndModern/BasicTestApp.lib.module.js

@@ -36,6 +36,7 @@ export function afterServerStarted() {
     appendElement('classic-and-modern-after-server-started', 'Classic and modern "afterServerStarted"');
 }
 
+// Duplicated in Components.TestServer\wwwroot\Components.TestServer.lib.module.js
 function appendElement(id, text) {
     var content = document.getElementById('initializers-content');
     if (!content) {

src/Components/test/testassets/Components.TestServer/RazorComponents/App.razor

@@ -43,9 +43,11 @@
             const enableClassicInitializers = sessionStorage.getItem('enable-classic-initializers') === 'true';
             const suppressEnhancedNavigation = sessionStorage.getItem('suppress-enhanced-navigation') === 'true';
             const blockLoadBootResource = sessionStorage.getItem('block-load-boot-resource') === 'true';
+            const blockWebassemblySettings = sessionStorage.getItem('block-webassembly-settings') === 'true';
             sessionStorage.removeItem('suppress-enhanced-navigation');
             sessionStorage.removeItem('block-load-boot-resource');
             sessionStorage.removeItem('enable-classic-initializers');
+            sessionStorage.removeItem('block-webassembly-settings');
 
             let loadBootResourceUnblocked = null;
             if (blockLoadBootResource) {
@@ -66,6 +68,35 @@
 
             let maxParallelResourceDownloadCount = 0;
             let currentParallelResourceDownloadCount = 0;
+            let webAssemblySettings = {
+                loadBootResource: function (type, name, defaultUri, integrity) {
+                    switch (type) {
+                        case 'manifest':
+                        case 'dotnetjs':
+                        case 'dotnetwasm':
+                            // note this is resolved to absolute URL using document.baseURI
+                            return `WasmMinimal/_framework/${name}`;
+                        default:
+                            // The following allows us to arbitrarily delay the loading of WebAssembly resources.
+                            // This is useful for guaranteeing that auto mode components will fall back on
+                            // using Blazor server.
+                            currentParallelResourceDownloadCount++;
+                            return fetch(`${document.baseURI}WasmMinimal/_framework/${name}?`, {
+                                method: "GET",
+                            }).then(async (response) => {
+                                if (currentParallelResourceDownloadCount > maxParallelResourceDownloadCount) {
+                                    maxParallelResourceDownloadCount = currentParallelResourceDownloadCount;
+                                    window['__aspnetcore__testing__max__parallel__resource__download__count'] = maxParallelResourceDownloadCount;
+                                }
+                                currentParallelResourceDownloadCount--;
+                                await loadBootResourceUnblocked;
+                                return response;
+                            });
+                    }
+                },
+            };
+            if (blockWebassemblySettings)
+                webAssemblySettings = null;
 
             Blazor.start({
                 ssr: {
@@ -75,33 +106,7 @@
                     circuitInactivityTimeoutMs: 100,
                 },
                 enableClassicInitializers: enableClassicInitializers,
-                webAssembly: {
-                    loadBootResource: function (type, name, defaultUri, integrity) {
-                        switch (type) {
-                            case 'manifest':
-                            case 'dotnetjs':
-                            case 'dotnetwasm':
-                                // note this is resolved to absolute URL using document.baseURI
-                                return `WasmMinimal/_framework/${name}`;
-                            default:
-                                // The following allows us to arbitrarily delay the loading of WebAssembly resources.
-                                // This is useful for guaranteeing that auto mode components will fall back on
-                                // using Blazor server.
-                                currentParallelResourceDownloadCount++;
-                                return fetch(`${document.baseURI}WasmMinimal/_framework/${name}?`, {
-                                    method: "GET",
-                                }).then(async (response) => {
-                                    if (currentParallelResourceDownloadCount > maxParallelResourceDownloadCount) {
-                                        maxParallelResourceDownloadCount = currentParallelResourceDownloadCount;
-                                        window['__aspnetcore__testing__max__parallel__resource__download__count'] = maxParallelResourceDownloadCount;
-                                    }
-                                    currentParallelResourceDownloadCount--;
-                                    await loadBootResourceUnblocked;
-                                    return response;
-                                });
-                        }
-                    },
-                },
+                webAssembly: webAssemblySettings,
                 circuit: {
                     reconnectionOptions: {
                         // It's easier to test the reconnection logic if we wait a bit

src/Components/test/testassets/Components.TestServer/wwwroot/Components.TestServer.lib.module.js

@@ -0,0 +1,19 @@
+export function beforeWebAssemblyStart() {
+    appendElement('server--classic-and-modern-before-web-assembly-start', 'Server project Classic and modern "beforeWebAssemblyStart"');
+}
+
+export function afterWebAssemblyStarted() {
+    appendElement('server--classic-and-modern-after-web-assembly-started', 'Server project Classic and modern "afterWebAssemblyStarted"');
+}
+
+// Duplicated in BasicTestApp\wwwroot\JSInitializers\ClassicAndModern\BasicTestApp.lib.module.js
+function appendElement(id, text) {
+    var content = document.getElementById('initializers-content');
+    if (!content) {
+        return;
+    }
+    var element = document.createElement('p');
+    element.id = id;
+    element.innerText = text;
+    content.appendChild(element);
+}