feat: adds support for relative paths to --filter-file-path (#106)

* feat): --filter-file-path to support relative paths

* chore: adds test case

Author: leonardochaia

src/DotnetAffected.Core/AffectedOptions.cs

@@ -25,7 +25,15 @@ public AffectedOptions(
             string? exclusionRegex = null)
         {
             RepositoryPath = DetermineRepositoryPath(repositoryPath, filterFilePath);
-            FilterFilePath = filterFilePath;
+
+            // Ensure the provided filter is a rooted path
+            if (!string.IsNullOrEmpty(filterFilePath))
+            {
+                FilterFilePath = Path.IsPathRooted(filterFilePath)
+                    ? filterFilePath
+                    : Path.Join(Environment.CurrentDirectory, filterFilePath);
+            }
+
             FromRef = fromRef ?? string.Empty;
             ToRef = toRef ?? string.Empty;
             ExclusionRegex = exclusionRegex;
@@ -76,8 +84,8 @@ private static string DetermineRepositoryPath(string? repositoryPath, string? fi
             var filterFileDirectory = Path.GetDirectoryName(filterfilePath);
             if (string.IsNullOrWhiteSpace(filterFileDirectory))
             {
-                throw new InvalidOperationException(
-                    $"Failed to determine directory from filter file path path. Ensure the path exists: {filterfilePath}");
+                // A relative path to a file may be provided, in such case getting the directory name fails.
+                return Environment.CurrentDirectory;
             }
 
             return filterFileDirectory;

test/dotnet-affected.Tests/PathGenerationTests.cs

@@ -14,23 +14,30 @@ private class RepositoryPathsClassData : IEnumerable<object[]>
         {
             public IEnumerator<object[]> GetEnumerator()
             {
+                yield return new object[] { "/home/lchaia/dotnet-affected", "", "/home/lchaia/dotnet-affected", null };
                 yield return new object[]
                 {
-                    "/home/lchaia/dotnet-affected", "", "/home/lchaia/dotnet-affected"
+                    "", "/home/lchaia/dotnet-affected/Affected.sln",
+                    Path.GetDirectoryName("/home/lchaia/dotnet-affected/Affected.sln"),
+                    "/home/lchaia/dotnet-affected/Affected.sln"
                 };
                 yield return new object[]
                 {
-                    "", "/home/lchaia/dotnet-affected/Affected.sln",
-                    Path.GetDirectoryName("/home/lchaia/dotnet-affected/Affected.sln")
+                    "/home/lchaia/dotnet-affected", "/home/lchaia/dotnet-affected/subdirectory/other/Affected.sln",
+                    "/home/lchaia/dotnet-affected", "/home/lchaia/dotnet-affected/subdirectory/other/Affected.sln",
                 };
+                yield return new object[] { "", "", Environment.CurrentDirectory, null };
+
                 yield return new object[]
                 {
-                    "/home/lchaia/dotnet-affected", "/home/lchaia/dotnet-affected/subdirectory/other/Affected.sln",
-                    "/home/lchaia/dotnet-affected"
+                    "", "Affected.sln", Environment.CurrentDirectory,
+                    Path.Join(Environment.CurrentDirectory, "Affected.sln")
                 };
+                
                 yield return new object[]
                 {
-                    "", "", Environment.CurrentDirectory
+                    "/home/lchaia/dotnet-affected", "Affected.sln", "/home/lchaia/dotnet-affected",
+                    Path.Join(Environment.CurrentDirectory, "Affected.sln")
                 };
             }
 
@@ -41,21 +48,20 @@ public IEnumerator<object[]> GetEnumerator()
         [ClassData(typeof(RepositoryPathsClassData))]
         public void Should_determine_repository_path_correctly(
             string repositoryPath,
-            string solutionPath,
-            string expected)
+            string filterFilePath,
+            string expectedRepository,
+            string expectedFilterFilePath)
         {
-            var options = new AffectedOptions(repositoryPath, solutionPath);
-            Assert.Equal(expected, options.RepositoryPath);
+            var options = new AffectedOptions(repositoryPath, filterFilePath);
+            Assert.Equal(expectedRepository, options.RepositoryPath);
+            Assert.Equal(expectedFilterFilePath, options.FilterFilePath);
         }
 
         private class OutputDirPathsClassData : IEnumerable<object[]>
         {
             public IEnumerator<object[]> GetEnumerator()
             {
-                yield return new object[]
-                {
-                    "/home/lchaia/dotnet-affected", "", "/home/lchaia/dotnet-affected"
-                };
+                yield return new object[] { "/home/lchaia/dotnet-affected", "", "/home/lchaia/dotnet-affected" };
                 yield return new object[]
                 {
                     "/home/lchaia/dotnet-affected", "relative/path",