Fixed merge for substitutions (#138)

* Added failing test

* Make substitution to use deep copy + fixed deep clone for some types

* NRE fix

* Fixed deep clone to take substitutions into account

src/Hocon.Configuration.Test/ConfigurationSpec.cs

@@ -8,6 +8,7 @@
 using System;
 using System.Configuration;
 using System.Linq;
+using FluentAssertions;
 using Xunit;
 using Xunit.Abstractions;
 
@@ -273,6 +274,26 @@ public void CanEnumerateQuotedKeys()
 
  Assert.Equal("some quoted, key", enumerable.Select(kvp => kvp.Key).First());
  }
+
+ [Fact]
+ public void CanSubstituteArrayCorrectly()
+ {
+ var hocon = @"
+ c: {
+ q: {
+ a: [2, 5]
+ }
+}
+c: {
+ m: ${c.q} {a: [6]}
+}
+";
+ var config = ConfigurationFactory.ParseString(hocon);
+ var unchanged = config.GetIntList("c.q.a");
+ unchanged.Should().Equal(new [] { 2, 5 });
+ var changed = config.GetIntList("c.m.a");
+ changed.Should().Equal(new [] { 6 });
+ }
 
  [Fact]
  public void CanParseSerializersAndBindings()

src/Hocon.Configuration.Test/Hocon.Configuration.Tests.csproj

@@ -6,6 +6,7 @@
  </PropertyGroup>
 
  <ItemGroup>
+ <PackageReference Include="FluentAssertions" Version="5.9.0" />
  <PackageReference Include="Microsoft.NET.Test.Sdk" Version="$(TestSdkVersion)" />
  <PackageReference Include="xunit" Version="$(XunitVersion)" />
  <DotNetCliToolReference Include="dotnet-xunit" Version="$(XunitCliVersion)" />

src/Hocon/Extensions/HoconElementExtensions.cs

@@ -0,0 +1,19 @@
+namespace Hocon.Extensions
+{
+ /// <summary>
+ /// HoconElementExtensions
+ /// </summary>
+ public static class HoconElementExtensions
+ {
+ /// <summary>
+ /// Performs deep clone of the element's value.
+ /// This is generally the same as <see cref="IHoconElement.Clone"/>, but
+ /// for substitutions it returns the substitution itself since it's value will be closed
+ /// during resolution process.
+ /// </summary>
+ public static IHoconElement CloneValue(this IHoconElement hoconElement, IHoconElement newParent)
+ {
+ return hoconElement is HoconSubstitution ? hoconElement : hoconElement.Clone(newParent);
+ }
+ }
+}

src/Hocon/Impl/HoconObject.cs

@@ -11,6 +11,7 @@
 using System.Linq;
 using System.Runtime.InteropServices.ComTypes;
 using System.Text;
+using Hocon.Extensions;
 
 namespace Hocon
 {
@@ -400,7 +401,7 @@ public IHoconElement Clone(IHoconElement newParent)
  var clone = new HoconObject(newParent);
  foreach (var kvp in this)
  {
- clone.SetField(kvp.Key, kvp.Value);
+ clone.SetField(kvp.Key, kvp.Value.CloneValue(clone) as HoconField);
  }
  return clone;
  }

src/Hocon/Impl/HoconValue.cs

@@ -13,6 +13,7 @@
 using System.Text;
 using System.Text.RegularExpressions;
 using System.Threading;
+using Hocon.Extensions;
 
 namespace Hocon
 {
@@ -706,7 +707,7 @@ public virtual IHoconElement Clone(IHoconElement newParent)
  var clone = new HoconValue(newParent);
  foreach (var element in this)
  {
- clone.Add(element);
+ clone.Add(element.CloneValue(clone));
  }
  return clone;
  }

src/Hocon/Parser.cs

@@ -1,4 +1,4 @@
-//-----------------------------------------------------------------------
+//-----------------------------------------------------------------------
 // <copyright file="Parser.cs" company="Hocon Project">
 // Copyright (C) 2009-2018 Lightbend Inc. <https://www.lightbend.com>
 // Copyright (C) 2013-2018 .NET Foundation <https://github.com/akkadotnet/hocon>
@@ -184,7 +184,7 @@ private HoconValue ResolveSubstitution(HoconSubstitution sub)
 
  // third case, regular substitution
  _root.GetObject().TryGetValue(sub.Path, out var field);
- return field;
+ return field?.Clone(field.Parent) as HoconValue;
  }
 
  private bool IsValueCyclic(HoconField field, HoconSubstitution sub)