Fix issue where Assembly.Load breaks if dll is unreferenced

Author: marner2

src/Serilog.Settings.Configuration/Settings/Configuration/Assemblies/AssemblyFinder.cs

@@ -5,7 +5,7 @@ namespace Serilog.Settings.Configuration.Assemblies;
 
 abstract class AssemblyFinder
 {
-    public abstract IReadOnlyList<AssemblyName> FindAssembliesContainingName(string nameToFind);
+    public abstract IReadOnlyList<(AssemblyName, string?)> FindAssembliesContainingName(string nameToFind);
 
     protected static bool IsCaseInsensitiveMatch(string? text, string textToFind)
     {

src/Serilog.Settings.Configuration/Settings/Configuration/Assemblies/CompositeAssemblyFinder.cs

@@ -11,9 +11,9 @@ public CompositeAssemblyFinder(params AssemblyFinder[] assemblyFinders)
         _assemblyFinders = assemblyFinders;
     }
 
-    public override IReadOnlyList<AssemblyName> FindAssembliesContainingName(string nameToFind)
+    public override IReadOnlyList<(AssemblyName, string?)> FindAssembliesContainingName(string nameToFind)
     {
-        var assemblyNames = new List<AssemblyName>();
+        var assemblyNames = new List<(AssemblyName, string?)>();
         foreach (var assemblyFinder in _assemblyFinders)
         {
             assemblyNames.AddRange(assemblyFinder.FindAssembliesContainingName(nameToFind));

src/Serilog.Settings.Configuration/Settings/Configuration/Assemblies/DependencyContextAssemblyFinder.cs

@@ -12,16 +12,16 @@ public DependencyContextAssemblyFinder(DependencyContext? dependencyContext)
         _dependencyContext = dependencyContext;
     }
 
-    public override IReadOnlyList<AssemblyName> FindAssembliesContainingName(string nameToFind)
+    public override IReadOnlyList<(AssemblyName, string?)> FindAssembliesContainingName(string nameToFind)
     {
         if (_dependencyContext == null)
-            return Array.Empty<AssemblyName>();
+            return Array.Empty<(AssemblyName, string?)>();
 
         var query = from library in _dependencyContext.RuntimeLibraries
                     where IsReferencingSerilog(library)
                     from assemblyName in library.GetDefaultAssemblyNames(_dependencyContext)
                     where IsCaseInsensitiveMatch(assemblyName.Name, nameToFind)
-                    select assemblyName;
+                    select (assemblyName, (string?)null);
 
         return query.ToList();
 

src/Serilog.Settings.Configuration/Settings/Configuration/Assemblies/DllScanningAssemblyFinder.cs

@@ -4,7 +4,7 @@ namespace Serilog.Settings.Configuration.Assemblies;
 
 sealed class DllScanningAssemblyFinder : AssemblyFinder
 {
-    public override IReadOnlyList<AssemblyName> FindAssembliesContainingName(string nameToFind)
+    public override IReadOnlyList<(AssemblyName, string?)> FindAssembliesContainingName(string nameToFind)
     {
         var probeDirs = new List<string>();
 
@@ -46,7 +46,7 @@ from outputAssemblyPath in Directory.GetFiles(probeDir, "*.dll")
                     where IsCaseInsensitiveMatch(assemblyFileName, nameToFind)
                     let assemblyName = TryGetAssemblyNameFrom(outputAssemblyPath)
                     where assemblyName != null
-                    select assemblyName;
+                    select (assemblyName, outputAssemblyPath);
 
         return query.ToList();
 

src/Serilog.Settings.Configuration/Settings/Configuration/ConfigurationReader.cs

@@ -355,9 +355,9 @@ static IReadOnlyCollection<Assembly> LoadConfigurationAssemblies(IConfiguration
             }
         }
 
-        foreach (var assemblyName in assemblyFinder.FindAssembliesContainingName("serilog"))
+        foreach (var (assemblyName, path) in assemblyFinder.FindAssembliesContainingName("serilog"))
         {
-            var assumed = Assembly.Load(assemblyName);
+            var assumed = path == null ? Assembly.Load(assemblyName) : Assembly.LoadFrom(path);
             assemblies.Add(assumed);
         }