Defensive checks on ReliabilitySetting

Author: dylan-asos

src/SendGrid/Reliability/ReliabilitySettings.cs

@@ -7,23 +7,58 @@ namespace SendGrid.Reliability
     /// </summary>
     public class ReliabilitySettings
     {
+        private int retryCount;
+        private TimeSpan retryInterval;
+
         /// <summary>
         /// Initializes a new instance of the <see cref="ReliabilitySettings"/> class.
         /// </summary>
         public ReliabilitySettings()
         {
-            RetryCount = 0;
-            RetryInterval = TimeSpan.FromSeconds(1);
+            retryCount = 0;
+            retryInterval = TimeSpan.FromSeconds(1);
         }
 
         /// <summary>
         ///     Gets or sets the number of retries to execute against an HTTP service endpoint before throwing an exceptions. Defaults to 0 (no retries, you must explicitly enable)
         /// </summary>
-        public int RetryCount { get; set; }
+        public int RetryCount
+        {
+            get
+            {
+                return retryCount;
+            }
+
+            set
+            {
+                if (value < 0)
+                {
+                    throw new ArgumentException("Retry count must be greater than zero");
+                }
+
+                retryCount = value;
+            }
+        }
 
         /// <summary>
         /// Gets or sets the interval between HTTP retries. Defaults to 1 second
         /// </summary>
-        public TimeSpan RetryInterval { get; set; }
+        public TimeSpan RetryInterval
+        {
+            get
+            {
+                return retryInterval;
+            }
+
+            set
+            {
+                if (value.TotalSeconds > 30)
+                {
+                    throw new ArgumentException("Maximum retry interval is 30 seconds");
+                }
+
+                retryInterval = value;
+            }
+        }
     }
 }

tests/SendGrid.Tests/Reliability/RetryDelegatingHandlerTests.cs

@@ -91,5 +91,21 @@ await Assert.ThrowsAsync<HttpRequestException>(
 
             Assert.Equal(3, innerHandler.InvocationCount);
         }
+
+        [Fact]
+        public void ReliabilitySettingsShouldNotAllowNegativeRetryCount()
+        {
+            var settings = new ReliabilitySettings();
+
+            Assert.Throws<ArgumentException>(() => settings.RetryCount = -1);
+        }
+
+        [Fact]
+        public void ReliabilitySettingsShouldNotAllowRetryIntervalGreaterThan30Seconds()
+        {
+            var settings = new ReliabilitySettings();
+
+            Assert.Throws<ArgumentException>(() => settings.RetryInterval = TimeSpan.FromSeconds(31));
+        }
     }
 }