Fixes #41: Add & AddRange cleanup partial adds after an exception

akade · Jul 11, 2023 · b6a0290 · b6a0290
1 parent 2f3deb0
commit b6a0290
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Showing 2 changed files with 58 additions and 4 deletions.
diff --git a/Akade.IndexedSet.Tests/GeneralTests.cs b/Akade.IndexedSet.Tests/GeneralTests.cs
@@ -62,4 +62,38 @@ public void Updating_immutable_key_value_updates_index()
         Assert.AreEqual(_a.PrimaryKey, _indexedSet.Single(x => x.IntProperty, 42).PrimaryKey);
         Assert.IsFalse(_indexedSet.Where(x => x.IntProperty, 0).Any(a => a.PrimaryKey == _a.PrimaryKey));
     }
+
+    [TestMethod]
+    public void Adding_a_conflicting_item_should_keep_the_set_in_a_consistent_state()
+    {
+        IndexedSet<TestData> set = new[] { _a, _c, _d }.ToIndexedSet()
+                                                       .WithIndex(x => x.GuidProperty)
+                                                       .WithUniqueIndex(x => x.IntProperty)
+                                                       .Build();
+
+        _ = Assert.ThrowsException<ArgumentException>(() => set.Add(_b));
+        Assert.IsFalse(set.TryGetSingle(x => x.GuidProperty, _b.GuidProperty, out _));
+        Assert.AreEqual(3, set.Count);
+        Assert.IsFalse(set.Contains(_b));
+    }
+
+    [TestMethod]
+    public void Adding_multiple_items_with_a_conflicting_item_should_keep_the_set_in_a_consistent_state()
+    {
+        IndexedSet<TestData> set = new[] { _a, _c, }.ToIndexedSet()
+                                                    .WithIndex(x => x.GuidProperty)
+                                                    .WithUniqueIndex(x => x.IntProperty)
+                                                    .Build();
+        TestData[] dataToAdd = new[] { _d, _b, _e };
+
+        _ = Assert.ThrowsException<ArgumentException>(() => set.AddRange(dataToAdd));
+        Assert.AreEqual(2, set.Count);
+
+        foreach (TestData item in dataToAdd)
+        {
+            Assert.IsFalse(set.TryGetSingle(x => x.GuidProperty, _b.GuidProperty, out _));
+            Assert.IsFalse(set.Contains(item));
+
+        }
+    }
 }
diff --git a/Akade.IndexedSet/IndexedSet.cs b/Akade.IndexedSet/IndexedSet.cs
@@ -43,9 +43,18 @@ public bool Add(TElement element)
             return false;
         }
 
-        foreach (Index<TElement> index in _indices.Values)
+        try
         {
-            index.Add(element);
+            foreach (Index<TElement> index in _indices.Values)
+            {
+                index.Add(element);
+            }
+        }
+        catch
+        {
+            _ = Remove(element);
+
+            throw;
         }
 
         return true;
@@ -81,9 +90,20 @@ public int AddRange(IEnumerable<TElement> elements)
             }
         }
 
-        foreach (Index<TElement> index in _indices.Values)
+        try
         {
-            index.AddRange(elementsToAdd);
+            foreach (Index<TElement> index in _indices.Values)
+            {
+                index.AddRange(elementsToAdd);
+            }
+        }
+        catch
+        {
+            foreach (TElement element in elementsToAdd)
+            {
+                _ = Remove(element);
+            }
+            throw;
         }
 
         return elementsToAdd.Count;