Add test coverage

WIP: new tests succeed in isolation (time-based/brittle)
optimizely · mikechu-optimizely · Jun 27, 2023 · Jun 22, 2023 · Jun 22, 2023 · Jun 22, 2023
commit a470f90dcefed94694830e689bdd6ebe5a3ffde9
diff --git a/OptimizelySDK.Tests/ConfigTest/HttpProjectConfigManagerTest.cs b/OptimizelySDK.Tests/ConfigTest/HttpProjectConfigManagerTest.cs
@@ -15,6 +15,7 @@
  */
 
 using System;
+using System.Collections.Generic;
 using System.Net;
 using System.Net.Http;
 using System.Threading.Tasks;
@@ -92,10 +93,40 @@ public void TestHttpConfigManagerWithInvalidStatus()
         }
 
         [Test]
-        public void TestSettingLastModifiedHeader()
+        public void TestSettingIfModifiedSinceInRequestHeader()
         {
-            // TODO: Start here
-            MockSendAsync(statusCode: HttpStatusCode.NotModified);
+            var t = MockSendAsync(
+                datafile: string.Empty,
+                statusCode: HttpStatusCode.NotModified
+            );
+
+            var httpManager = new HttpProjectConfigManager.Builder()
+                .WithDatafile(string.Empty)
+                .WithLogger(LoggerMock.Object)
+                .WithPollingInterval(TimeSpan.FromMilliseconds(1000))
+                .WithBlockingTimeoutPeriod(TimeSpan.FromMilliseconds(4000))
+                .WithStartByDefault()
+                .Build();
+            httpManager.LastModifiedSince = new DateTime(2020, 4, 4).ToString("R");
+            t.Wait(5000);
+
+            LoggerMock.Verify(
+                _ => _.Log(LogLevel.DEBUG, "Set If-Modified-Since in request header."),
+                Times.AtLeastOnce);
+
+            httpManager.Dispose();
+        }
+
+        [Test]
+        public void TestSettingLastModifiedFromResponseHeader()
+        {
+            MockSendAsync(
+                statusCode: HttpStatusCode.OK,
+                responseContentHeaders: new Dictionary<string, string>
+                {
+                    { "Last-Modified", new DateTime(2050, 10, 10).ToString("R") },
+                }
+            );
 
             var httpManager = new HttpProjectConfigManager.Builder()
                 .WithUrl("https://cdn.optimizely.com/datafiles/QBw9gFM8oTn7ogY9ANCC1z.json")
@@ -561,12 +592,13 @@ public void TestFormatUrlHigherPriorityThanDefaultUrl()
             httpManager.Dispose();
         }
 
-        public Task MockSendAsync(string datafile = null, TimeSpan? delay = null,
-            HttpStatusCode statusCode = HttpStatusCode.OK
+        private Task MockSendAsync(string datafile = null, TimeSpan? delay = null,
+            HttpStatusCode statusCode = HttpStatusCode.OK,
+            Dictionary<string, string> responseContentHeaders = null
         )
         {
             return TestHttpProjectConfigManagerUtil.MockSendAsync(HttpClientMock, datafile, delay,
-                statusCode);
+                statusCode, responseContentHeaders);
         }
 
         #endregion

diff --git a/OptimizelySDK.Tests/Utils/TestHttpProjectConfigManagerUtil.cs b/OptimizelySDK.Tests/Utils/TestHttpProjectConfigManagerUtil.cs
@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020, Optimizely
+ * Copyright 2019-2020, 2023 Optimizely
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,6 +15,7 @@
  */
 
 using System;
+using System.Collections.Generic;
 using System.Net;
 using System.Net.Http;
 using System.Threading.Tasks;
@@ -28,27 +29,38 @@ namespace OptimizelySDK.Tests.Utils
     /// </summary>
     public static class TestHttpProjectConfigManagerUtil
     {
-        public static Task MockSendAsync(Mock<HttpProjectConfigManager.HttpClient> HttpClientMock,
+        public static Task MockSendAsync(Mock<HttpProjectConfigManager.HttpClient> httpClientMock,
             string datafile = null, TimeSpan? delay = null,
-            HttpStatusCode statusCode = HttpStatusCode.OK
+            HttpStatusCode statusCode = HttpStatusCode.OK,
+            Dictionary<string, string> responseContentHeaders = null
         )
         {
             var t = new TaskCompletionSource<bool>();
 
-            HttpClientMock.Setup(_ => _.SendAsync(It.IsAny<HttpRequestMessage>())).
+            httpClientMock.Setup(_ => _.SendAsync(It.IsAny<HttpRequestMessage>())).
                 Returns(() =>
                 {
                     if (delay != null)
                     {
                         // This delay mocks the networking delay. And help to see the behavior when get a datafile with some delay.
                         Task.Delay(delay.Value).Wait();
                     }
-
-                    return Task.FromResult<HttpResponseMessage>(new HttpResponseMessage
+                    
+                    var responseMessage = new HttpResponseMessage
                     {
                         StatusCode = statusCode,
                         Content = new StringContent(datafile ?? string.Empty),
-                    });
+                    };
+
+                    if (responseContentHeaders != null)
+                    {
+                        foreach (var header in responseContentHeaders)
+                        {
+                            responseMessage.Content.Headers.Add(header.Key, header.Value);
+                        }
+                    }
+
+                    return Task.FromResult(responseMessage);
                 }).
                 Callback(()
                     =>
@@ -69,7 +81,10 @@ public static void SetClientFieldValue(object value)
             var field = type.GetField("Client",
                 System.Reflection.BindingFlags.Static |
                 System.Reflection.BindingFlags.NonPublic);
-            field.SetValue(new object(), value);
+            if (field != null)
+            {
+                field.SetValue(new object(), value);
+            }
         }
     }
 }
diff --git a/OptimizelySDK/Config/HttpProjectConfigManager.cs b/OptimizelySDK/Config/HttpProjectConfigManager.cs
@@ -19,6 +19,7 @@
 #endif
 
 using System;
+using System.Net;
 using System.Threading.Tasks;
 using OptimizelySDK.ErrorHandler;
 using OptimizelySDK.Logger;
@@ -29,7 +30,7 @@ namespace OptimizelySDK.Config
     public class HttpProjectConfigManager : PollingProjectConfigManager
     {
         private string Url;
-        private string LastModifiedSince = string.Empty;
+        internal string LastModifiedSince = string.Empty;
         privat
AE3F
e string DatafileAccessToken = string.Empty;
 
         private HttpProjectConfigManager(TimeSpan period, string url, TimeSpan blockingTimeout,
@@ -118,6 +119,7 @@ private string GetRemoteDatafileResponse()
             if (!string.IsNullOrEmpty(LastModifiedSince))
             {
                 request.Headers.Add("If-Modified-Since", LastModifiedSince);
+                Logger.Log(LogLevel.DEBUG, $"Set If-Modified-Since in request header.");
             }
 
             if (!string.IsNullOrEmpty(DatafileAccessToken))
@@ -132,6 +134,12 @@ private string GetRemoteDatafileResponse()
 
             // Return from here if datafile is not modified.
             var result = httpResponse.Result;
+
+            if (result.StatusCode == HttpStatusCode.NotModified)
+            {
+                return null;
+            }
+
             if (!result.IsSuccessStatusCode)
             {
                 Logger.Log(LogLevel.ERROR, $"Error fetching datafile \"{result.StatusCode}\"");
@@ -145,11 +153,6 @@ private string GetRemoteDatafileResponse()
                 Logger.Log(LogLevel.DEBUG, $"Set LastModifiedSince from response header.");
             }
 
-            if (result.StatusCode == System.Net.HttpStatusCode.NotModified)
-            {
-                return null;
-            }
-
             var content = result.Content.ReadAsStringAsync();
             content.Wait();