Add unit test to check create and revoke token endpoint

Author: KoditkarVedant

Test/Notion.IntegrationTests/AuthenticationTests.cs

@@ -0,0 +1,39 @@
+using System.Threading.Tasks;
+using Notion.Client;
+using Xunit;
+
+namespace Notion.IntegrationTests;
+
+public class AuthenticationTests : IntegrationTestBase
+{
+    private readonly string _clientId = GetEnvironmentVariableRequired("NOTION_CLIENT_ID");
+    private readonly string _clientSecret = GetEnvironmentVariableRequired("NOTION_CLIENT_SECRET");
+
+    [Fact]
+    public async Task Create_and_revoke_token()
+    {
+        // Arrange
+        var createRequest = new CreateTokenRequest
+        {
+            Code = "03b3bd2d-6b96-4104-a9f4-ee04d881532c",
+            ClientId = _clientId,
+            ClientSecret = _clientSecret,
+            RedirectUri = "https://localhost:5001",
+        };
+
+        // Act
+        var response = await Client.AuthenticationClient.CreateTokenAsync(createRequest);
+
+        // Assert
+        Assert.NotNull(response);
+        Assert.NotNull(response.AccessToken);
+        
+        // revoke token
+        await Client.AuthenticationClient.RevokeTokenAsync(new RevokeTokenRequest
+        {
+            Token = response.AccessToken,
+            ClientId = _clientId,
+            ClientSecret = _clientSecret
+        });
+    }
+}

Test/Notion.IntegrationTests/IntegrationTestBase.cs

@@ -15,10 +15,13 @@ protected IntegrationTestBase()
 
         Client = NotionClientFactory.Create(options);
 
-        ParentPageId = Environment.GetEnvironmentVariable("NOTION_PARENT_PAGE_ID")
-                       ?? throw new InvalidOperationException("Parent page id is required.");
-
-        ParentDatabaseId = Environment.GetEnvironmentVariable("NOTION_PARENT_DATABASE_ID")
-                           ?? throw new InvalidOperationException("Parent database id is required.");
+        ParentPageId = GetEnvironmentVariableRequired("NOTION_PARENT_PAGE_ID");
+        ParentDatabaseId = GetEnvironmentVariableRequired("NOTION_PARENT_DATABASE_ID");
+    }
+    
+    protected static string GetEnvironmentVariableRequired(string envName)
+    {
+        return Environment.GetEnvironmentVariable(envName) ??
+               throw new InvalidOperationException($"Environment variable '{envName}' is required.");
     }
 }