scan all ProgramFiles dirs

fixes #22

src/DiffEngine.Tests/OrderReaderTest.cs

@@ -22,7 +22,8 @@ public void BadEnvironmentVariable()
         Assert.Equal("Unable to parse tool from `DiffEngine.ToolOrder` environment variable: Foo", exception.Message);
     }
 
-    public OrderReaderTest(ITestOutputHelper output) : base(output)
+    public OrderReaderTest(ITestOutputHelper output) :
+        base(output)
     {
     }
 }

src/DiffEngine.Tests/OsSettingsResolverTest.cs

@@ -0,0 +1,28 @@
+using System.Linq;
+using Xunit;
+using Xunit.Abstractions;
+
+public class OsSettingsResolverTest :
+    XunitContextBase
+{
+    [Fact]
+    public void Simple()
+    {
+        var paths = OsSettingsResolver.ExpandProgramFiles(new[] {"Path"}).ToList();
+        Assert.Equal("Path", paths.Single());
+    }
+
+    [Fact]
+    public void Expand()
+    {
+        var paths = OsSettingsResolver.ExpandProgramFiles(new[] {@"%ProgramFiles%\Path"}).ToList();
+        Assert.Equal(@"%ProgramFiles%\Path", paths[0]);
+        Assert.Equal(@"%ProgramW6432%\Path", paths[1]);
+        Assert.Equal(@"%ProgramFiles(x86)%\Path", paths[2]);
+    }
+
+    public OsSettingsResolverTest(ITestOutputHelper output) :
+        base(output)
+    {
+    }
+}

src/DiffEngine/DiffEngine.csproj

@@ -6,7 +6,9 @@
     <TargetFrameworks>netstandard2.0;netstandard2.1;net461</TargetFrameworks>
   </PropertyGroup>
   <ItemGroup>
+    <PackageReference Include="Caseless.Fody" Version="1.9.0" PrivateAssets="All" />
     <PackageReference Include="EmptyFiles" Version="2.0.3" PrivateAssets="None" />
+    <PackageReference Include="Fody" Version="6.1.1" PrivateAssets="All" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" Condition="$(Configuration) == 'Release'" />
     <PackageReference Include="ProjectDefaults" Version="1.0.42" PrivateAssets="All" />
     <PackageReference Include="Nullable" Version="1.2.1" PrivateAssets="All" />

src/DiffEngine/FodyWeavers.xml

@@ -0,0 +1,3 @@
+<Weavers xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" GenerateXsd="false">
+  <Caseless />
+</Weavers>

src/DiffEngine/OsSettingsResolver.cs

@@ -1,4 +1,5 @@
-using System.Diagnostics.CodeAnalysis;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.InteropServices;
 using DiffEngine;
 
@@ -14,7 +15,9 @@ public static bool Resolve(
         if (windows != null &&
             RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
         {
-            if (WildcardFileFinder.TryFindExe(windows.ExePaths, out path))
+            var paths = ExpandProgramFiles(windows.ExePaths);
+
+            if (WildcardFileFinder.TryFindExe(paths, out path))
             {
                 arguments = windows.Arguments;
                 return true;
@@ -45,4 +48,22 @@ public static bool Resolve(
         arguments = null;
         return false;
     }
+
+    public static IEnumerable<string> ExpandProgramFiles(IEnumerable<string> paths)
+    {
+        // Note: Windows can have multiple paths, and will resolve %ProgramFiles% as 'C:\Program Files (x86)'
+        // when running inside a 32-bit process. To
+        // overcome this issue, we need to manually add any option so the correct paths will be resolved
+
+        foreach (var windowsPath in paths)
+        {
+            yield return windowsPath;
+
+            if (windowsPath.Contains("%ProgramFiles%"))
+            {
+                yield return windowsPath.Replace("%ProgramFiles%", "%ProgramW6432%");
+                yield return windowsPath.Replace("%ProgramFiles%", "%ProgramFiles(x86)%");
+            }
+        }
+    }
 }

src/DiffEngine/WildcardFileFinder.cs

@@ -64,7 +64,7 @@ public static bool TryFindExe(
         IEnumerable<string> paths,
         [NotNullWhen(true)] out string? exePath)
     {
-        foreach (var path in paths)
+        foreach (var path in paths.Distinct(StringComparer.OrdinalIgnoreCase))
         {
             if (TryFind(path, out exePath))
             {

src/Directory.Build.props

@@ -2,7 +2,7 @@
 <Project>
   <PropertyGroup>
     <NoWarn>CS1591;CS0649</NoWarn>
-    <Version>3.1.0</Version>
+    <Version>3.1.1</Version>
     <AssemblyVersion>1.0.0.0</AssemblyVersion>
     <PackageTags>Json, Testing, Verify, Snapshot, Approvals</PackageTags>
     <Description>Enables simple verification of complex models and documents.</Description>