Core - Fix removing dynamic children and checking which properties are in use

- DataModel.RemoveDynamicChild compared the value of each child with the
  child that was passed in, so it never removed anything.
- IsPropertyInUse with includeChildren matched paths by their start, so
  a path to "Integers" made "Integer" count as in use. Children are now
  matched on what follows a dot.

src/Artemis.Core.Tests/DataModels/DataModelTests.cs

@@ -184,7 +184,7 @@ public class DataModelTests : IDisposable
     }
 
     [Fact]
-    public void RemovingADynamicChild_DoesNotRemoveIt()
+    public void RemovingADynamicChild_RemovesIt()
     {
         DynamicChild<int> child = DataModel.AddDynamicChild("Extra", 5);
         int removed = 0;
@@ -192,11 +192,8 @@ public class DataModelTests : IDisposable
 
         DataModel.RemoveDynamicChild(child);
 
-        // Pinned as-is: RemoveDynamicChild compares the value of each child (BaseValue) with the child that was passed in,
-        // rather than the child itself, so it only removes a child whose value is the child object. Looks like it should
-        // compare the children themselves; RemoveDynamicChildByKey works.
-        DataModel.DynamicChildren.ShouldContainKey("Extra");
-        removed.ShouldBe(0);
+        DataModel.DynamicChildren.ShouldNotContainKey("Extra");
+        removed.ShouldBe(1);
     }
 
     [Fact]
@@ -304,14 +301,14 @@ public class DataModelTests : IDisposable
     }
 
     [Fact]
-    public void IncludingChildren_AlsoMatchesPropertiesThatStartWithTheSameName()
+    public void IncludingChildren_DoesNotMatchPropertiesThatStartWithTheSameName()
     {
         using DataModelPath path = new(DataModel, "Integers");
 
-        // Pinned as-is: children are matched by checking whether a path starts with the given text, so "Integer" counts as
-        // in use because of a path to "Integers", a different property. Looks like it should check for "Integer."
-        _module.IsPropertyInUse("Integer", true).ShouldBeTrue();
+        // Integers is a different property than Integer, not a child of it
+        _module.IsPropertyInUse("Integer", true).ShouldBeFalse();
         _module.IsPropertyInUse("Integer", false).ShouldBeFalse();
+        _module.IsPropertyInUse("Integers", true).ShouldBeTrue();
     }
 
     [Fact]

src/Artemis.Core/Plugins/Modules/DataModel.cs

@@ -289,7 +289,7 @@ public abstract class DataModel
     public void RemoveDynamicChild(DynamicChild dynamicChild)
     {
         if (dynamicChild == null) throw new ArgumentNullException(nameof(dynamicChild));
-        List<string> keys = _dynamicChildren.Where(kvp => kvp.Value.BaseValue == dynamicChild).Select(kvp => kvp.Key).ToList();
+        List<string> keys = _dynamicChildren.Where(kvp => kvp.Value == dynamicChild).Select(kvp => kvp.Key).ToList();
         foreach (string key in keys)
         {
             _dynamicChildren.Remove(key);
@@ -335,8 +335,10 @@ public abstract class DataModel
     {
         lock (_activePaths)
         {
+            // A child's path continues after a dot, matching on the text alone would also match a property that merely starts
+            // with the same name (Integer and Integers)
             return includeChildren
-                ? _activePathsHashSet.Any(p => p.StartsWith(path, PathsStringComparison))
+                ? _activePathsHashSet.Any(p => string.Equals(p, path, PathsStringComparison) || p.StartsWith(path + ".", PathsStringComparison))
                 : _activePathsHashSet.Contains(path);
         }
     }