WIP SPA routing

README.md

@@ -32,6 +32,7 @@ I'm also shamelessly promoting some of my projects that nobody else is using (in
 ## ASP.NET Core and Angular cookbook
 
 - [Mitigate CSRF](docs/aspnet-core/csrf/README.md)
+- [SPA routing](docs/aspnet-core/spa-routing/README.md)
 
 ## Instant nuggets
 

docs/aspnet-core/spa-routing/README.md

@@ -0,0 +1,45 @@
+# SPA routing
+
+I like separating the `SPA` and `API` codebase (they could still live in the same repository but in different directories). If you do end up deploying the `SPA` in the `wwwroot/` directory of the `API`
+
+```csharp
+public class SpaRoutingMiddleware
+{
+    private readonly RequestDelegate _next;
+
+    public SpaRoutingMiddleware(RequestDelegate next)
+    {
+        _next = next;
+    }
+
+    public Task InvokeAsync(HttpContext context)
+    {
+        if (IsGetMethod(context) && !IsApiPath(context) && !HasExtension(context))
+        {
+            context.Request.Path = "/index.html";
+        }
+
+        return _next(context);
+    }
+
+    private static bool IsGetMethod(HttpContext context)
+    {
+        return context.Request.Method == HttpMethods.Get;
+    }
+
+    private static bool IsApiPath(HttpContext context)
+    {
+        return context.Request.Path.StartsWithSegments("/api");
+    }
+
+    private static bool HasExtension(HttpContext context)
+    {
+        if (!context.Request.Path.HasValue)
+            return false;
+
+        var startIndex = context.Request.Path.Value.LastIndexOf('.');
+
+        return startIndex >= 0;
+    }
+}
+```