Add GitHubApiStatusService.IsAbuseRateLimit

Author: TheCodeTraveler

Src/GitHubApiStatus.UnitTests/GitHubApiStatus.UnitTests.csproj

@@ -11,7 +11,7 @@
   <ItemGroup>
     <PackageReference Include="nunit" Version="3.12.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
     <PackageReference Include="RichardSzalay.MockHttp" Version="6.0.0" />
   </ItemGroup>
 

Src/GitHubApiStatus.UnitTests/Tests/Base/BaseTest.cs

@@ -27,7 +27,7 @@ protected virtual Task AfterEachTest()
             return Task.CompletedTask;
         }
 
-        protected static HttpResponseHeaders CreateHttpResponseHeaders(in int rateLimit, in DateTimeOffset rateLimitResetTime, in int remainingRequestCount, in HttpStatusCode httpStatusCode = HttpStatusCode.OK, in bool isAuthenticated = true)
+        protected static HttpResponseHeaders CreateHttpResponseHeaders(in int rateLimit, in DateTimeOffset rateLimitResetTime, in int remainingRequestCount, in HttpStatusCode httpStatusCode = HttpStatusCode.OK, in bool isAuthenticated = true, in bool isAbuseRateLimit = false)
         {
             if (remainingRequestCount > rateLimit)
                 throw new ArgumentOutOfRangeException(nameof(remainingRequestCount), $"{nameof(remainingRequestCount)} must be less than or equal to {nameof(rateLimit)}");
@@ -42,6 +42,9 @@ protected static HttpResponseHeaders CreateHttpResponseHeaders(in int rateLimit,
                 }
             };
 
+            if (isAbuseRateLimit)
+                httpResponse.Headers.RetryAfter = new RetryConditionHeaderValue(TimeSpan.FromMinutes(1));
+
             if (isAuthenticated)
                 httpResponse.Headers.Vary.Add(_authorizationHeaderKey);
 

Src/GitHubApiStatus.UnitTests/Tests/IsAbuseRateLimitTest.cs

@@ -0,0 +1,49 @@
+using System;
+using NUnit.Framework;
+
+namespace GitHubApiStatus.UnitTests
+{
+    class IsAbuseRateLimitTest : BaseTest
+    {
+        [Test]
+        public void IsAbuseRateLimit()
+        {
+            //Arrange
+            var httpResponseHeaders = CreateHttpResponseHeaders(500, DateTimeOffset.UtcNow, 0, isAbuseRateLimit: true);
+
+            //Act
+            var isAbuseRateLimit = GitHubApiStatusService.IsAbuseRateLimit(httpResponseHeaders, out TimeSpan? delta);
+
+            //Assert
+            Assert.IsTrue(isAbuseRateLimit);
+            Assert.IsNotNull(delta);
+        }
+
+        [Test]
+        public void IsNotAbuseRateLimit()
+        {
+            //Arrange
+            var httpResponseHeaders = CreateHttpResponseHeaders(500, DateTimeOffset.UtcNow, 0);
+
+            //Act
+            var isAbuseRateLimit = GitHubApiStatusService.IsAbuseRateLimit(httpResponseHeaders, out TimeSpan? delta);
+
+            //Assert
+            Assert.IsFalse(isAbuseRateLimit);
+            Assert.IsNull(delta);
+        }
+
+        [Test]
+        public void NullHttpResponseHeaders()
+        {
+            //Arrange
+
+            //Act
+
+            //Assert
+#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference type.
+            Assert.Throws<GitHubApiStatusException>(() => GitHubApiStatusService.IsAbuseRateLimit(null, out _));
+#pragma warning restore CS8625 // Cannot convert null literal to non-nullable reference type.
+        }
+    }
+}

Src/GitHubApiStatus.UnitTests/Tests/ProductHeaderValueTests.cs

@@ -32,7 +32,9 @@ public void NullNameTest()
             //Act
 
             //Assert
+#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference type.
             Assert.Throws<ArgumentException>(() => gitHubApiStatusService.AddProductHeaderValue(new ProductHeaderValue(null)));
+#pragma warning restore CS8625 // Cannot convert null literal to non-nullable reference type.
             Assert.IsFalse(gitHubApiStatusService.IsProductHeaderValueValid);
         }
 

Src/GitHubApiStatus/Services/GitHubApiStatusService.cs

@@ -170,12 +170,26 @@ public int GetRateLimit(in HttpResponseHeaders httpResponseHeaders)
         {
             ValidateHttpResponseHeaders(httpResponseHeaders);
 
-            var rateLimitRemainingHeader = httpResponseHeaders?.Single(x => x.Key.Equals(RateLimitHeader, StringComparison.OrdinalIgnoreCase)) ?? throw new ArgumentNullException(nameof(httpResponseHeaders));
+            var rateLimitRemainingHeader = httpResponseHeaders.Single(x => x.Key.Equals(RateLimitHeader, StringComparison.OrdinalIgnoreCase));
             var rateLimit = int.Parse(rateLimitRemainingHeader.Value.First());
 
             return rateLimit;
         }
 
+        /// <summary>
+        /// Determines Whether GitHub's Abuse Rate Limit Has Been Reached
+        /// </summary>
+        /// <param name="httpResponseHeaders">HttpResponseHeaders from GitHub API Response</param>
+        /// <param name="delta">Time Remaining in Retry-After Header</param>
+        /// <returns></returns>
+        public bool IsAbuseRateLimit(in HttpResponseHeaders httpResponseHeaders, out TimeSpan? delta)
+        {
+            ValidateHttpResponseHeaders(httpResponseHeaders);
+
+            delta = httpResponseHeaders.RetryAfter?.Delta;
+            return delta is not null;
+        }
+
         /// <summary>
         /// Determines Whether GitHub's Maximum API Limit Has Been Reached
         /// </summary>
@@ -196,7 +210,7 @@ public int GetRemainingRequestCount(in HttpResponseHeaders httpResponseHeaders)
         {
             ValidateHttpResponseHeaders(httpResponseHeaders);
 
-            var rateLimitRemainingHeader = httpResponseHeaders?.Single(x => x.Key.Equals(RateLimitRemainingHeader, StringComparison.OrdinalIgnoreCase)) ?? throw new ArgumentNullException(nameof(httpResponseHeaders));
+            var rateLimitRemainingHeader = httpResponseHeaders.Single(x => x.Key.Equals(RateLimitRemainingHeader, StringComparison.OrdinalIgnoreCase));
             var remainingApiRequests = int.Parse(rateLimitRemainingHeader.Value.First());
 
             return remainingApiRequests;

Src/GitStatus.API/GetRateLimits.cs

@@ -16,11 +16,9 @@ class GitHubApiStatus
         public GitHubApiStatus(IGitHubApiStatusService gitHubApiStatusService) => _gitHubApiStatusService = gitHubApiStatusService;
 
         [FunctionName(nameof(GitHubApiStatus))]
-        public async Task<IActionResult> Run(
-            [HttpTrigger(AuthorizationLevel.Function, "get", Route = null)] HttpRequest req,
-            ILogger log)
+        public async Task<IActionResult> Run([HttpTrigger(AuthorizationLevel.Function, "get", Route = null)] HttpRequest req, ILogger log)
         {
-            log.LogInformation("C# HTTP trigger function processed a request.");
+            log.LogInformation("Retrieving Api Rate Limits");
 
             var apiStatus = await _gitHubApiStatusService.GetApiRateLimits(CancellationToken.None).ConfigureAwait(false);