Fix docs and exception messages for Change (#1085)

Author: xackus

src/DynamicData/Cache/Change.cs

@@ -28,7 +28,7 @@ public Change(ChangeReason reason, TKey key, TObject current, int index = -1)
 
     /// <summary>
     /// Initializes a new instance of the <see cref="Change{TObject, TKey}"/> struct.
-    /// Constructor for ChangeReason.Move.
+    /// Constructor for <see cref="ChangeReason.Moved"/>.
     /// </summary>
     /// <param name="key">The key.</param>
     /// <param name="current">The current.</param>
@@ -70,9 +70,9 @@ public Change(TKey key, TObject current, int currentIndex, int previousIndex)
     /// <param name="currentIndex">Value of the current.</param>
     /// <param name="previousIndex">Value of the previous.</param>
     /// <exception cref="ArgumentException">
-    /// For ChangeReason.Add, a previous value cannot be specified
+    /// For <see cref="ChangeReason.Add"/>, a previous value cannot be specified
     /// or
-    /// For ChangeReason.Change, must supply previous value.
+    /// For <see cref="ChangeReason.Update"/>, must supply previous value.
     /// </exception>
     public Change(ChangeReason reason, TKey key, TObject current, in Optional<TObject> previous, int currentIndex = -1, int previousIndex = -1)
         : this()
@@ -91,7 +91,7 @@ public Change(ChangeReason reason, TKey key, TObject current, in Optional<TObjec
 
         if (reason == ChangeReason.Update && !previous.HasValue)
         {
-            throw new ArgumentException("For ChangeReason.Change, must supply previous value");
+            throw new ArgumentException("For ChangeReason.Update, must supply previous value");
         }
     }
 
@@ -101,7 +101,7 @@ public Change(ChangeReason reason, TKey key, TObject current, in Optional<TObjec
     public TKey Key { get; }
 
     /// <summary>
-    /// Gets the  reason for the change.
+    /// Gets the reason for the change.
     /// </summary>
     public ChangeReason Reason { get; }
 
@@ -116,14 +116,14 @@ public Change(ChangeReason reason, TKey key, TObject current, in Optional<TObjec
     public int CurrentIndex { get; }
 
     /// <summary>
-    /// <para>Gets the previous change.</para>
-    /// <para>This is only when Reason==ChangeReason.Replace.</para>
+    /// <para>Gets the item from before the change.</para>
+    /// <para>This is only when <see cref="Reason"/> is <see cref="ChangeReason.Update"/>.</para>
     /// </summary>
     public Optional<TObject> Previous { get; }
 
     /// <summary>
-    /// <para>Gets the previous change.</para>
-    /// <para>This is only when Reason==ChangeReason.Update or ChangeReason.Move.</para>
+    /// <para>Gets the previous index.</para>
+    /// <para>This is only when <see cref="Reason"/> is <see cref="ChangeReason.Update"/> or <see cref="ChangeReason.Moved"/>.</para>
     /// </summary>
     public int PreviousIndex { get; }
 

src/DynamicData/List/Change.cs

@@ -47,7 +47,7 @@ public Change(ListChangeReason reason, IEnumerable<T> items, int index = -1)
 
     /// <summary>
     /// Initializes a new instance of the <see cref="Change{T}"/> class.
-    /// Constructor for ChangeReason.Move.
+    /// Constructor for <see cref="ListChangeReason.Moved"/>.
     /// </summary>
     /// <param name="current">The current.</param>
     /// <param name="currentIndex">The CurrentIndex.</param>
@@ -84,25 +84,27 @@ public Change(T current, int currentIndex, int previousIndex)
     /// <param name="currentIndex">Value of the current.</param>
     /// <param name="previousIndex">Value of the previous.</param>
     /// <exception cref="ArgumentException">
-    /// For ChangeReason.Add, a previous value cannot be specified
+    /// For <see cref="ListChangeReason.Add"/>, a previous value cannot be specified
     /// or
-    /// For ChangeReason.Change, must supply previous value.
+    /// For <see cref="ListChangeReason.Replace"/>, must supply previous value.
+    /// or
+    /// For <see cref="ListChangeReason.Refresh"/>, must supply an index.
     /// </exception>
     public Change(ListChangeReason reason, T current, in Optional<T> previous, int currentIndex = -1, int previousIndex = -1)
     {
         if (reason == ListChangeReason.Add && previous.HasValue)
         {
-            throw new ArgumentException("For ChangeReason.Add, a previous value cannot be specified");
+            throw new ArgumentException("For ListChangeReason.Add, a previous value cannot be specified");
         }
 
         if (reason == ListChangeReason.Replace && !previous.HasValue)
         {
-            throw new ArgumentException("For ChangeReason.Replace, must supply previous value");
+            throw new ArgumentException("For ListChangeReason.Replace, must supply previous value");
         }
 
         if (reason == ListChangeReason.Refresh && currentIndex < 0)
         {
-            throw new ArgumentException("For ChangeReason.Refresh, must supply an index");
+            throw new ArgumentException("For ListChangeReason.Refresh, must supply an index");
         }
 
         Reason = reason;

src/DynamicData/List/ItemChange.cs

@@ -67,14 +67,14 @@ public ItemChange(ListChangeReason reason, T current, int currentIndex)
     public int CurrentIndex { get; }
 
     /// <summary>
-    /// <para>Gets the previous change.</para>
-    /// <para>This is only when Reason==ChangeReason.Replace.</para>
+    /// <para>Gets the item from before the change.</para>
+    /// <para>This is only when <see cref="Reason"/> is <see cref="ListChangeReason.Replace"/>.</para>
     /// </summary>
     public Optional<T> Previous { get; }
 
     /// <summary>
     /// <para>Gets the previous index.</para>
-    /// <para>This is only when Reason==ChangeReason.Replace or ChangeReason.Move.</para>
+    /// <para>This is only when <see cref="Reason"/> is <see cref="ListChangeReason.Replace"/> or <see cref="ListChangeReason.Moved"/>.</para>
     /// </summary>
     public int PreviousIndex { get; }
 

src/DynamicData/List/RangeChange.cs

@@ -63,7 +63,7 @@ private RangeChange()
     public IEnumerator<T> GetEnumerator() => _items.GetEnumerator();
 
     /// <summary>
-    /// Inserts the  item in the range at the specified index.
+    /// Inserts the item in the range at the specified index.
     /// </summary>
     /// <param name="index">The index.</param>
     /// <param name="item">The item.</param>