From da467a10b01c1c465ed312711c2498910ef15571 Mon Sep 17 00:00:00 2001
From: Alex Barney <thealexbarney@gmail.com>
Date: Tue, 7 Jan 2020 22:51:59 -0700
Subject: [PATCH] Add ToU8String method to U8Span. Add PathTools.GetFileName

---
 src/LibHac/Common/U8Span.cs          |  5 +++++
 src/LibHac/Common/U8SpanMutable.cs   |  5 +++++
 src/LibHac/FsSystem/PathTools.cs     | 16 ++++++++++++++++
 tests/LibHac.Tests/PathToolsTests.cs | 24 ++++++++++++++++++++++++
 4 files changed, 50 insertions(+)

diff --git a/src/LibHac/Common/U8Span.cs b/src/LibHac/Common/U8Span.cs
index e36ad0c4..3e46ab0d 100644
--- a/src/LibHac/Common/U8Span.cs
+++ b/src/LibHac/Common/U8Span.cs
@@ -47,6 +47,11 @@ namespace LibHac.Common
             return StringUtils.Utf8ZToString(_buffer);
         }
 
+        public U8String ToU8String()
+        {
+            return new U8String(_buffer.ToArray());
+        }
+
         public bool IsNull() => _buffer == default;
     }
 }
diff --git a/src/LibHac/Common/U8SpanMutable.cs b/src/LibHac/Common/U8SpanMutable.cs
index 3570d7ab..c89d5c34 100644
--- a/src/LibHac/Common/U8SpanMutable.cs
+++ b/src/LibHac/Common/U8SpanMutable.cs
@@ -51,6 +51,11 @@ namespace LibHac.Common
             return StringUtils.Utf8ZToString(_buffer);
         }
 
+        public U8StringMutable ToU8String()
+        {
+            return new U8StringMutable(_buffer.ToArray());
+        }
+
         public bool IsNull() => _buffer == default;
     }
 }
diff --git a/src/LibHac/FsSystem/PathTools.cs b/src/LibHac/FsSystem/PathTools.cs
index 837a8e57..3b689de7 100644
--- a/src/LibHac/FsSystem/PathTools.cs
+++ b/src/LibHac/FsSystem/PathTools.cs
@@ -246,6 +246,22 @@ namespace LibHac.FsSystem
             return path.Slice(0, i);
         }
 
+        /// <summary>
+        /// Returns the name and extension parts of the given path. The returned ReadOnlySpan
+        /// contains the characters of the path that follows the last separator in path.
+        /// </summary>
+        public static ReadOnlySpan<byte> GetFileName(ReadOnlySpan<byte> path)
+        {
+            Debug.Assert(IsNormalized(path));
+
+            int i = path.Length;
+
+            while (i >= 1 && path[i - 1] != '/') i--;
+
+            i = Math.Max(i, 0);
+            return path.Slice(i, path.Length - i);
+        }
+
         public static bool IsNormalized(ReadOnlySpan<char> path)
         {
             var state = NormalizeState.Initial;
diff --git a/tests/LibHac.Tests/PathToolsTests.cs b/tests/LibHac.Tests/PathToolsTests.cs
index 1435c0a2..e4450321 100644
--- a/tests/LibHac.Tests/PathToolsTests.cs
+++ b/tests/LibHac.Tests/PathToolsTests.cs
@@ -275,5 +275,29 @@ namespace LibHac.Tests
             Assert.Equal(Math.Max(0, destSize - 1), normalizedLength);
             Assert.Equal(expected, actual);
         }
+
+        public static object[][] GetFileNameTestItems =
+        {
+            new object[] {"/a/bb/ccc", "ccc"},
+            new object[] {"/a/bb/ccc/", ""},
+            new object[] {"/a/bb", "bb"},
+            new object[] {"/a/bb/", ""},
+            new object[] {"/a", "a"},
+            new object[] {"/a/", ""},
+            new object[] {"/", ""},
+        };
+
+        [Theory]
+        [MemberData(nameof(GetFileNameTestItems))]
+        public static void GetFileNameTest(string path, string expected)
+        {
+            var u8Path = path.ToU8String();
+
+            ReadOnlySpan<byte> fileName = PathTools.GetFileName(u8Path);
+
+            string actual = StringUtils.Utf8ZToString(fileName);
+
+            Assert.Equal(expected, actual);
+        }
     }
 }