Adding in handling for secondary rate limit exceptions

Octokit.Tests/Http/ConnectionTests.cs

@@ -180,7 +180,7 @@ public async Task ThrowsApiValidationExceptionFor422Response()
             }
 
             [Fact]
-            public async Task ThrowsRateLimitExceededExceptionForForbidderResponse()
+            public async Task ThrowsRateLimitExceededExceptionForForbiddenResponse()
             {
                 var httpClient = Substitute.For<IHttpClient>();
                 var response = CreateResponse(
@@ -202,6 +202,28 @@ public async Task ThrowsRateLimitExceededExceptionForForbidderResponse()
                     exception.Message);
             }
 
+            [Fact]
+            public async Task ThrowsSecondaryRateLimitExceededExceptionForForbiddenResponse()
+            {
+                var httpClient = Substitute.For<IHttpClient>();
+                var response = CreateResponse(
+                    HttpStatusCode.Forbidden,
+                    "{\"message\":\"You have exceeded a secondary rate limit. Please wait a few minutes before you try again.\"}");
+
+                httpClient.Send(Args.Request, Args.CancellationToken).Returns(Task.FromResult(response));
+                var connection = new Connection(new ProductHeaderValue("OctokitTests"),
+                    _exampleUri,
+                    Substitute.For<ICredentialStore>(),
+                    httpClient,
+                    Substitute.For<IJsonSerializer>());
+
+                var exception = await Assert.ThrowsAsync<SecondaryRateLimitExceededException>(
+                    () => connection.GetResponse<string>(new Uri("endpoint", UriKind.Relative)));
+
+                Assert.Equal("You have exceeded a secondary rate limit. Please wait a few minutes before you try again.",
+                    exception.Message);
+            }
+
             [Fact]
             public async Task ThrowsLoginAttemptsExceededExceptionForForbiddenResponse()
             {

Octokit/Exceptions/SecondaryRateLimitExceededException.cs

@@ -0,0 +1,67 @@
+using System;
+using System.Diagnostics.CodeAnalysis;
+#if !NO_SERIALIZABLE
+using System.Runtime.Serialization;
+#endif
+
+namespace Octokit
+{
+    /// <summary>
+    /// Exception thrown when Secondary GitHub API Rate limits are exceeded.
+    /// </summary>
+    /// <summary>
+    /// <para>
+    /// This occurs when GitHub perceives misuse of the API. You may get this if
+    /// you are polling heavily, creating content rapidly or making concurrent requests.
+    /// </para>
+    /// <para>See https://docs.github.com/en/rest/overview/resources-in-the-rest-api#secondary-rate-limits for more details.</para>
+    /// </summary>
+#if !NO_SERIALIZABLE
+    [Serializable]
+#endif
+    [SuppressMessage("Microsoft.Design", "CA1032:ImplementStandardExceptionConstructors",
+        Justification = "These exceptions are specific to the GitHub API and not general purpose exceptions")]
+    public class SecondaryRateLimitExceededException : ForbiddenException
+    {
+        /// <summary>
+        /// Constructs an instance of the <see cref="Octokit.SecondaryRateLimitExceededException"/> class.
+        /// </summary>
+        /// <param name="response">The HTTP payload from the server</param>
+        public SecondaryRateLimitExceededException(IResponse response) : this(response, null)
+        {
+        }
+
+        /// <summary>
+        /// Constructs an instance of the <see cref="Octokit.SecondaryRateLimitExceededException"/> class.
+        /// </summary>
+        /// <param name="response">The HTTP payload from the server</param>
+        /// <param name="innerException">The inner exception</param>
+        public SecondaryRateLimitExceededException(IResponse response, Exception innerException) : base(response, innerException)
+        {
+            Ensure.ArgumentNotNull(response, nameof(response));
+        }
+
+        public override string Message
+        {
+            get { return ApiErrorMessageSafe ?? "Secondary API Rate Limit exceeded"; }
+        }
+
+#if !NO_SERIALIZABLE
+        /// <summary>
+        /// Constructs an instance of <see  cref="Octokit.SecondaryRateLimitExceededException"/>.
+        /// </summary>
+        /// <param name="info">
+        /// The <see cref="SerializationInfo"/> that holds the
+        /// serialized object data about the exception being thrown.
+        /// </param>
+        /// <param name="context">
+        /// The <see cref="StreamingContext"/> that contains
+        /// contextual information about the source or destination.
+        /// </param>
+        protected SecondaryRateLimitExceededException(SerializationInfo info, StreamingContext context)
+            : base(info, context)
+        {
+        }
+#endif
+    }
+}

Octokit/Http/Connection.cs

@@ -724,6 +724,11 @@ static Exception GetExceptionForForbidden(IResponse response)
                 return new RateLimitExceededException(response);
             }
 
+            if (body.Contains("secondary rate limit"))
+            {
+                return new SecondaryRateLimitExceededException(response);
+            }
+
             if (body.Contains("number of login attempts exceeded"))
             {
                 return new LoginAttemptsExceededException(response);