add support to configure baseUrl & notion version

Author: KoditkarVedant

Src/Notion.Client/Constants.cs

@@ -1,9 +1,8 @@
-using System;
-
-namespace Notion.Client
+namespace Notion.Client
 {
     internal class Constants
     {
-        internal static Uri BASE_URL = new Uri("https://api.notion.com/v1/");
+        internal static string BASE_URL = "https://api.notion.com/v1/";
+        internal static string DEFAULT_NOTION_VERSION = "2021-05-13";
     }
 }

Src/Notion.Client/NotionClient.cs

@@ -2,10 +2,9 @@
 {
     public class NotionClient : INotionClient
     {
-        public NotionClient(string authToken)
+        public NotionClient(ClientOptions options)
         {
-            AuthToken = authToken;
-            Users = new UsersClient(new RestClient(authToken));
+            Users = new UsersClient(new RestClient(options));
         }
 
         public string AuthToken { get; }

Src/Notion.Client/RestClient.cs

@@ -1,4 +1,5 @@
-using System.Net.Http;
+using System;
+using System.Net.Http;
 using System.Net.Http.Headers;
 using System.Threading.Tasks;
 
@@ -11,12 +12,21 @@ public interface IRestClient
 
     public class RestClient : IRestClient
     {
-        private readonly string _authToken;
         private HttpClient _httpClient;
+        private readonly ClientOptions _options;
 
-        public RestClient(string authToken)
+        public RestClient(ClientOptions options)
         {
-            _authToken = authToken;
+            _options = MergeOptions(options);
+        }
+
+        private static ClientOptions MergeOptions(ClientOptions options)
+        {
+            return new ClientOptions {
+                AuthToken = options.AuthToken,
+                BaseUrl = options.BaseUrl ?? Constants.BASE_URL,
+                NotionVersion = options.NotionVersion ?? Constants.DEFAULT_NOTION_VERSION
+            };
         }
 
         public async Task<T> GetAsync<T>(string uri)
@@ -34,11 +44,18 @@ private HttpClient EnsureHttpClient()
             if(_httpClient == null)
             {
                 _httpClient = new HttpClient();
-                _httpClient.BaseAddress = Constants.BASE_URL;
-                _httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", _authToken);
+                _httpClient.BaseAddress = new Uri(_options.BaseUrl);
+                _httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", _options.AuthToken);
             }
 
             return _httpClient;
         }
     }
+
+    public class ClientOptions
+    {
+        public string BaseUrl { get; set; }
+        public string NotionVersion { get; set; }
+        public string AuthToken { get; set; }
+    }
 }

Test/Notion.UnitTests/UserClientTest.cs

@@ -6,13 +6,16 @@ namespace Notion.UnitTests
 {
     public class UserClientTest
     {
-        private readonly string _authToken;
         private readonly IUsersClient _client;
 
         public UserClientTest()
         {
-            _authToken = "<Token>";
-            _client = new UsersClient(new RestClient(_authToken));
+            var options = new ClientOptions
+            {
+                AuthToken = "<Token>"
+            };
+
+            _client = new UsersClient(new RestClient(options));
         }
 
         [Fact(Skip = "Internal testing purpose")]