Merge pull request #94 from novuhq/83-add-user-agent-header

feat: add version to user-agent header #83

src/Novu.Domain/NovuConstants.cs

@@ -1,6 +1,38 @@
+using System.Reflection;
+
 namespace Novu.Domain;
 
 public static class NovuConstants
 {
     public static readonly int MaxPageSize = 100;
+
+    /// <summary>
+    ///     Returns the properly formatted User-Agent header string for the `novu-dotnet` package,
+    ///     including the version retrieved from the NuGet package version.
+    /// </summary>
+    /// <returns>
+    ///     A string in the format `novu-dotnet/{version}`, where {version} is the version of the NuGet package.
+    ///     If no version is found, it defaults to `novu-dotnet/0.0.0`.
+    /// </returns>
+    /// <remarks>
+    ///     The version is retrieved from the assembly's <see cref="AssemblyInformationalVersionAttribute" />.
+    ///     If the version is not specified in the assembly, it falls back to `0.0.0` as the default version.
+    ///     This ensures compliance with the HTTP specification for the User-Agent header format, as outlined in RFC 7231.
+    /// </remarks>
+    /// <example>
+    ///     Example usage:
+    ///     <code>
+    ///         string userAgent = NovuConstants.UserAgent();
+    ///         Console.WriteLine(userAgent);  // Outputs: novu-dotnet/1.2.3 (if version is 1.2.3)
+    ///     </code>
+    /// </example>
+    public static string UserAgent()
+    {
+        // Add a User-Agent header if enabled
+        var version = Assembly
+            .GetExecutingAssembly()
+            .GetCustomAttribute<AssemblyInformationalVersionAttribute>()?
+            .InformationalVersion ?? "0.0.0";
+        return $"novu-dotnet/{version}";
+    }
 }

src/Novu.Extensions/IocNovuRegistrationExtensions.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Net.Http;
+using System.Reflection;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Novu.Clients;
@@ -16,22 +17,11 @@ public static class IocNovuRegistrationExtensions
     public static IServiceCollection RegisterNovuClients(
         this IServiceCollection services,
         IConfiguration configuration,
-        RefitSettings refitSettings = null)
+        RefitSettings refitSettings = null,
+        Action<HttpClient> configureHttpClient = null)
     {
         var novuConfiguration = configuration.GetNovuClientConfiguration();
-
-        Action<HttpClient> configureClient = client =>
-        {
-            client.BaseAddress = new Uri(novuConfiguration.Url);
-
-            // allow for multiple registrations—authorization cannot have multiple entries
-            if (client.DefaultRequestHeaders.Contains("Authorization"))
-            {
-                client.DefaultRequestHeaders.Remove("Authorization");
-            }
-
-            client.DefaultRequestHeaders.Add("Authorization", $"ApiKey {novuConfiguration.ApiKey}");
-        };
+        var configureClient = configureHttpClient ?? ConfigureClient(novuConfiguration);
         var settings = RefitSettings(refitSettings);
 
         services.AddRefitClient<ISubscriberClient>(settings).ConfigureHttpClient(configureClient);
@@ -60,6 +50,42 @@ public static IServiceCollection RegisterNovuClients(
     }
 
 
+    /// <summary>
+    ///     Configures an <see cref="HttpClient" /> with the necessary headers for Novu API communication.
+    /// </summary>
+    /// <remarks>
+    ///     Hand this into the configuration with includeUserAgent as false to turn off
+    /// </remarks>
+    /// <param name="novuConfiguration">The configuration containing the Novu API base URL and API key.</param>
+    /// <param name="includeUserAgent">Indicates whether to include a custom User-Agent header. Default is true.</param>
+    /// <returns>
+    ///     An <see cref="Action{HttpClient}" /> that applies the necessary configuration to an <see cref="HttpClient" />
+    ///     instance.
+    /// </returns>
+    public static Action<HttpClient> ConfigureClient(
+        NovuClientConfiguration novuConfiguration,
+        bool includeUserAgent = true)
+    {
+        return client =>
+        {
+            // Set the base address for API requests
+            client.BaseAddress = new Uri(novuConfiguration.Url);
+
+            // Ensure only one Authorization header exists
+            if (client.DefaultRequestHeaders.Contains("Authorization"))
+            {
+                client.DefaultRequestHeaders.Remove("Authorization");
+            }
+
+            client.DefaultRequestHeaders.Add("Authorization", $"ApiKey {novuConfiguration.ApiKey}");
+            if (includeUserAgent)
+            {
+                var userAgent = NovuConstants.UserAgent();
+                client.DefaultRequestHeaders.Add("User-Agent", userAgent);
+            }
+        };
+    }
+
     public static IServiceCollection RegisterNovuClient(
         this IServiceCollection services,
         IConfiguration configuration,
@@ -70,7 +96,7 @@ public static IServiceCollection RegisterNovuClient(
                 configuration.GetNovuClientConfiguration(),
                 refitSettings: RefitSettings(refitSettings)));
     }
-    
+
     private static RefitSettings RefitSettings(RefitSettings refitSettings)
     {
         return refitSettings ?? new RefitSettings

src/Novu/NovuClient.cs

@@ -1,4 +1,5 @@
-using Novu.Clients;
+using System.Reflection;
+using Novu.Clients;
 using Novu.Domain;
 using Refit;
 
@@ -16,6 +17,7 @@ public NovuClient(
         var httpClient = client ?? new HttpClient();
         httpClient.BaseAddress = new Uri(configuration.Url);
         httpClient.DefaultRequestHeaders.Add(AuthorizationHeaderName, $"ApiKey {configuration.ApiKey}");
+        httpClient.DefaultRequestHeaders.Add("User-Agent", NovuConstants.UserAgent());
 
         refitSettings ??= new RefitSettings
         {