Disallow zero confirmations to prevent mistake

planetarium · Sep 4, 2020 · 251ede7 · 251ede7
1 parent 16faa43
commit 251ede7
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Showing 3 changed files with 39 additions and 0 deletions.
diff --git a/Libplanet.Tests/Blockchain/Renderers/DelayedActionRendererTest.cs b/Libplanet.Tests/Blockchain/Renderers/DelayedActionRendererTest.cs
@@ -19,6 +19,19 @@ public DelayedActionRendererTest(ITestOutputHelper output)
         {
         }
 
+        [Fact]
+        public override void Constructor()
+        {
+            ArgumentOutOfRangeException e = Assert.Throws<ArgumentOutOfRangeException>(() =>
+                new DelayedActionRenderer<DumbAction>(
+                    new AnonymousActionRenderer<DumbAction>(),
+                    _store,
+                    confirmations: 0
+                )
+            );
+            Assert.Equal("confirmations", e.ParamName);
+        }
+
         [Fact]
         public override void BlocksBeingAppended()
         {

diff --git a/Libplanet.Tests/Blockchain/Renderers/DelayedRendererTest.cs b/Libplanet.Tests/Blockchain/Renderers/DelayedRendererTest.cs
@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using Libplanet.Blockchain.Renderers;
@@ -65,6 +66,19 @@ public DelayedRendererTest(ITestOutputHelper output)
             }
         }
 
+        [Fact]
+        public virtual void Constructor()
+        {
+            ArgumentOutOfRangeException e = Assert.Throws<ArgumentOutOfRangeException>(() =>
+                new DelayedRenderer<DumbAction>(
+                    new AnonymousRenderer<DumbAction>(),
+                    _store,
+                    confirmations: 0
+                )
+            );
+            Assert.Equal("confirmations", e.ParamName);
+        }
+
         [Fact]
         public virtual void BlocksBeingAppended()
         {

diff --git a/Libplanet/Blockchain/Renderers/DelayedRenderer.cs b/Libplanet/Blockchain/Renderers/DelayedRenderer.cs
@@ -47,9 +47,21 @@ public class DelayedRenderer<T> : IRenderer<T>
         /// implementations and receives delayed events.</param>
         /// <param name="store">The same store to what <see cref="BlockChain{T}"/> uses.</param>
         /// <param name="confirmations">The required number of confirmations to recognize a block.
+        /// It must be greater than zero (note that zero <paramref name="confirmations"/> mean
+        /// nothing is delayed so that it is equivalent to the bare <paramref name="renderer"/>).
         /// See also the <see cref="Confirmations"/> property.</param>
+        /// <exception cref="ArgumentOutOfRangeException">Thrown when the argument
+        /// <paramref name="confirmations"/> is not greater than zero.</exception>
         public DelayedRenderer(IRenderer<T> renderer, IStore store, uint confirmations)
         {
+            if (confirmations < 1)
+            {
+                string msg =
+                    "Zero confirmations mean nothing is delayed so that it is equivalent to the " +
+                    $"bare {nameof(renderer)}; configure it to more than zero.";
+                throw new ArgumentOutOfRangeException(nameof(confirmations), msg);
+            }
+
             Logger = Log.ForContext(GetType());
             Renderer = renderer;
             Store = store;