Update WireMockProtoFileResolver and add tests for ProtoBufUtils (#1252)

* Update WireMockProtoFileResolver and add tests for ProtoBufUtils

* .

src/WireMock.Net.Abstractions/Models/IdOrTexts.cs

@@ -16,7 +16,7 @@ public readonly struct IdOrTexts
     public string? Id { get; }
 
     /// <summary>
-    /// The Text.
+    /// The Texts.
     /// </summary>
     public IReadOnlyList<string> Texts { get; }
 
@@ -41,7 +41,7 @@ public readonly struct IdOrTexts
     }
 
     /// <summary>
-    /// When Id is defined, return process the Id, else process the Texts.
+    /// When Id is defined, process the Id, else process the Texts.
     /// </summary>
     /// <param name="id">Callback to process the id.</param>
     /// <param name="texts">Callback to process the texts.</param>

src/WireMock.Net/Util/WireMockProtoFileResolver.cs

@@ -2,6 +2,7 @@
 
 #if PROTOBUF
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq;
 using ProtoBufJsonConverter;
@@ -9,21 +10,29 @@ using Stef.Validation;
 
 namespace WireMock.Util;
 
+/// <summary>
+/// This resolver is used to resolve the extra ProtoDefinition files.
+/// It assumes that:
+/// - the first ProtoDefinition file is the main ProtoDefinition file.
+/// - the first commented line of each extra ProtoDefinition file is the filename which is used in the import of the other ProtoDefinition file(s).
+/// </summary>
 internal class WireMockProtoFileResolver : IProtoFileResolver
 {
     private readonly Dictionary<string, string> _files = new();
 
     public WireMockProtoFileResolver(IReadOnlyCollection<string> protoDefinitions)
     {
-        if (Guard.NotNullOrEmpty(protoDefinitions).Count() > 1)
+        if (Guard.NotNullOrEmpty(protoDefinitions).Count() <= 1)
         {
-            foreach (var extraProtoDefinition in protoDefinitions.Skip(1))
+            return;
+        }
+
+        foreach (var extraProtoDefinition in protoDefinitions.Skip(1))
+        {
+            var firstNonEmptyLine = extraProtoDefinition.Split(['\r', '\n']).FirstOrDefault(l => !string.IsNullOrEmpty(l));
+            if (firstNonEmptyLine != null && TryGetValidFileName(firstNonEmptyLine.TrimStart(['/', ' ']), out var validFileName))
             {
-                var firstNonEmptyLine = extraProtoDefinition.Split(['\r', '\n']).FirstOrDefault(l => !string.IsNullOrEmpty(l));
-                if (firstNonEmptyLine != null)
-                {
-                    _files.Add(firstNonEmptyLine.TrimStart(['\r', '\n', '/', ' ']), extraProtoDefinition);
-                }
+                _files.Add(validFileName, extraProtoDefinition);
             }
         }
     }
@@ -42,5 +51,17 @@ internal class WireMockProtoFileResolver : IProtoFileResolver
 
         throw new FileNotFoundException($"The ProtoDefinition '{path}' was not found.");
     }
+
+    private static bool TryGetValidFileName(string fileName, [NotNullWhen(true)] out string? validFileName)
+    {
+        if (!fileName.Any(c => Path.GetInvalidFileNameChars().Contains(c)))
+        {
+            validFileName = fileName;
+            return true;
+        }
+
+        validFileName = null;
+        return false;
+    }
 }
 #endif