Update Extensions and add tests

SabreTools.Matching.Test/ExtensionsTests.cs

@@ -0,0 +1,344 @@
+using System;
+using Xunit;
+
+namespace SabreTools.Matching.Test
+{
+    public class ExtensionsTests
+    {
+        #region Find All Positions
+
+        [Fact]
+        public void FindAllPositions_EmptyStack_NoMatches()
+        {
+            byte[] stack = [];
+            var positions = stack.FindAllPositions([0x01]);
+            Assert.Empty(positions);
+        }
+
+        [Fact]
+        public void FindAllPositions_EmptyNeedle_NoMatches()
+        {
+            byte[] stack = [0x01];
+            var positions = stack.FindAllPositions(Array.Empty<byte>());
+            Assert.Empty(positions);
+        }
+
+        [Fact]
+        public void FindAllPositions_LongerNeedle_NoMatches()
+        {
+            byte[] stack = [0x01];
+            var positions = stack.FindAllPositions([0x01, 0x02]);
+            Assert.Empty(positions);
+        }
+
+        [Fact]
+        public void FindAllPositions_InvalidStart_NoMatches()
+        {
+            byte[] stack = [0x01];
+            var positions = stack.FindAllPositions([0x01, 0x02], start: -1);
+            Assert.Empty(positions);
+
+            positions = stack.FindAllPositions([0x01, 0x02], start: 2);
+            Assert.Empty(positions);
+        }
+
+        [Fact]
+        public void FindAllPositions_InvalidEnd_NoMatches()
+        {
+            byte[] stack = [0x01];
+            var positions = stack.FindAllPositions([0x01, 0x02], end: -2);
+            Assert.Empty(positions);
+
+            positions = stack.FindAllPositions([0x01, 0x02], end: 0);
+            Assert.Empty(positions);
+
+            positions = stack.FindAllPositions([0x01, 0x02], end: 2);
+            Assert.Empty(positions);
+        }
+
+        [Fact]
+        public void FindAllPositions_Matching_Matches()
+        {
+            byte[] stack = [0x01, 0x02];
+            var positions = stack.FindAllPositions([0x01, 0x02]);
+            int position = Assert.Single(positions);
+            Assert.Equal(0, position);
+        }
+
+        [Fact]
+        public void FindAllPositions_Mismatch_NoMatches()
+        {
+            byte[] stack = [0x01, 0x03];
+            var positions = stack.FindAllPositions([0x01, 0x02]);
+            Assert.Empty(positions);
+        }
+
+        [Fact]
+        public void FindAllPositions_Multiple_Matches()
+        {
+            byte[] stack = [0x01, 0x01];
+            var positions = stack.FindAllPositions([0x01]);
+            Assert.Equal(2, positions.Count);
+        }
+
+        #endregion
+
+        #region First Position
+
+        [Fact]
+        public void FirstPosition_EmptyStack_NoMatches()
+        {
+            byte[] stack = [];
+            int position = stack.FirstPosition([0x01]);
+            Assert.Equal(-1, position);
+        }
+
+        [Fact]
+        public void FirstPosition_EmptyNeedle_NoMatches()
+        {
+            byte[] stack = [0x01];
+            int position = stack.FirstPosition(Array.Empty<byte>());
+            Assert.Equal(-1, position);
+        }
+
+        [Fact]
+        public void FirstPosition_LongerNeedle_NoMatches()
+        {
+            byte[] stack = [0x01];
+            int position = stack.FirstPosition([0x01, 0x02]);
+            Assert.Equal(-1, position);
+        }
+
+        [Fact]
+        public void FirstPosition_InvalidStart_NoMatches()
+        {
+            byte[] stack = [0x01];
+            int position = stack.FirstPosition([0x01, 0x02], start: -1);
+            Assert.Equal(-1, position);
+
+            position = stack.FirstPosition([0x01, 0x02], start: 2);
+            Assert.Equal(-1, position);
+        }
+
+        [Fact]
+        public void FirstPosition_InvalidEnd_NoMatches()
+        {
+            byte[] stack = [0x01];
+            int position = stack.FirstPosition([0x01, 0x02], end: -2);
+            Assert.Equal(-1, position);
+
+            position = stack.FirstPosition([0x01, 0x02], end: 0);
+            Assert.Equal(-1, position);
+
+            position = stack.FirstPosition([0x01, 0x02], end: 2);
+            Assert.Equal(-1, position);
+        }
+
+        [Fact]
+        public void FirstPosition_Matching_Matches()
+        {
+            byte[] stack = [0x01, 0x02];
+            int position = stack.FirstPosition([0x01, 0x02]);
+            Assert.Equal(0, position);
+        }
+
+        [Fact]
+        public void FirstPosition_Mismatch_NoMatches()
+        {
+            byte[] stack = [0x01, 0x03];
+            int position = stack.FirstPosition([0x01, 0x02]);
+            Assert.Equal(-1, position);
+        }
+
+        [Fact]
+        public void FirstPosition_Multiple_Matches()
+        {
+            byte[] stack = [0x01, 0x01];
+            int position = stack.FirstPosition([0x01]);
+            Assert.Equal(0, position);
+        }
+
+        #endregion
+
+        #region Last Position
+
+        [Fact]
+        public void LastPosition_EmptyStack_NoMatches()
+        {
+            byte[] stack = [];
+            int position = stack.LastPosition([0x01]);
+            Assert.Equal(-1, position);
+        }
+
+        [Fact]
+        public void LastPosition_EmptyNeedle_NoMatches()
+        {
+            byte[] stack = [0x01];
+            int position = stack.LastPosition(Array.Empty<byte>());
+            Assert.Equal(-1, position);
+        }
+
+        [Fact]
+        public void LastPosition_LongerNeedle_NoMatches()
+        {
+            byte[] stack = [0x01];
+            int position = stack.LastPosition([0x01, 0x02]);
+            Assert.Equal(-1, position);
+        }
+
+        [Fact]
+        public void LastPosition_InvalidStart_NoMatches()
+        {
+            byte[] stack = [0x01];
+            int position = stack.LastPosition([0x01, 0x02], start: -1);
+            Assert.Equal(-1, position);
+
+            position = stack.LastPosition([0x01, 0x02], start: 2);
+            Assert.Equal(-1, position);
+        }
+
+        [Fact]
+        public void LastPosition_InvalidEnd_NoMatches()
+        {
+            byte[] stack = [0x01];
+            int position = stack.LastPosition([0x01, 0x02], end: -2);
+            Assert.Equal(-1, position);
+
+            position = stack.LastPosition([0x01, 0x02], end: 0);
+            Assert.Equal(-1, position);
+
+            position = stack.LastPosition([0x01, 0x02], end: 2);
+            Assert.Equal(-1, position);
+        }
+
+        [Fact]
+        public void LastPosition_Matching_Matches()
+        {
+            byte[] stack = [0x01, 0x02];
+            int position = stack.LastPosition([0x01, 0x02]);
+            Assert.Equal(0, position);
+        }
+
+        [Fact]
+        public void LastPosition_Mismatch_NoMatches()
+        {
+            byte[] stack = [0x01, 0x03];
+            int position = stack.LastPosition([0x01, 0x02]);
+            Assert.Equal(-1, position);
+        }
+
+        [Fact]
+        public void LastPosition_Multiple_Matches()
+        {
+            byte[] stack = [0x01, 0x01];
+            int position = stack.LastPosition([0x01]);
+            Assert.Equal(1, position);
+        }
+
+        #endregion
+
+        #region Starts With
+
+        [Fact]
+        public void StartsWith_EmptyStack_NoMatches()
+        {
+            byte[] stack = [];
+            bool found = stack.StartsWith([0x01]);
+            Assert.False(found);
+        }
+
+        [Fact]
+        public void StartsWith_EmptyNeedle_NoMatches()
+        {
+            byte[] stack = [0x01];
+            bool found = stack.StartsWith(Array.Empty<byte>());
+            Assert.False(found);
+        }
+
+        [Fact]
+        public void StartsWith_LongerNeedle_NoMatches()
+        {
+            byte[] stack = [0x01];
+            bool found = stack.StartsWith([0x01, 0x02]);
+            Assert.False(found);
+        }
+
+        [Fact]
+        public void StartsWith_Matching_Matches()
+        {
+            byte[] stack = [0x01, 0x02];
+            bool found = stack.StartsWith([0x01, 0x02]);
+            Assert.True(found);
+        }
+
+        [Fact]
+        public void StartsWith_Mismatch_NoMatches()
+        {
+            byte[] stack = [0x01, 0x03];
+            bool found = stack.StartsWith([0x01, 0x02]);
+            Assert.False(found);
+        }
+
+        [Fact]
+        public void StartsWith_Multiple_Matches()
+        {
+            byte[] stack = [0x01, 0x01];
+            bool found = stack.StartsWith([0x01]);
+            Assert.True(found);
+        }
+
+        #endregion
+
+        #region Ends With
+
+        [Fact]
+        public void EndsWith_EmptyStack_NoMatches()
+        {
+            byte[] stack = [];
+            bool found = stack.EndsWith([0x01]);
+            Assert.False(found);
+        }
+
+        [Fact]
+        public void EndsWith_EmptyNeedle_NoMatches()
+        {
+            byte[] stack = [0x01];
+            bool found = stack.EndsWith(Array.Empty<byte>());
+            Assert.False(found);
+        }
+
+        [Fact]
+        public void EndsWith_LongerNeedle_NoMatches()
+        {
+            byte[] stack = [0x01];
+            bool found = stack.StartsWith([0x01, 0x02]);
+            Assert.False(found);
+        }
+
+        [Fact]
+        public void EndsWith_Matching_Matches()
+        {
+            byte[] stack = [0x01, 0x02];
+            bool found = stack.EndsWith([0x01, 0x02]);
+            Assert.True(found);
+        }
+
+        [Fact]
+        public void EndsWith_Mismatch_NoMatches()
+        {
+            byte[] stack = [0x01, 0x03];
+            bool found = stack.EndsWith([0x01, 0x02]);
+            Assert.False(found);
+        }
+
+        [Fact]
+        public void EndsWith_Multiple_Matches()
+        {
+            byte[] stack = [0x01, 0x01];
+            bool found = stack.EndsWith([0x01]);
+            Assert.True(found);
+        }
+
+        #endregion
+    }
+}

SabreTools.Matching/Content/ContentMatch.cs

@@ -93,13 +93,21 @@ namespace SabreTools.Matching.Content
             if (stack == null || stack.Length == 0 || Needle.Length == 0)
                 return -1;
 
-            // If the needle array is larger than the stack array, it can't be contained within
-            if (Needle.Length > stack.Length)
+            // Get the adjusted end value for comparison
+            int end = _end < 0 ? stack.Length : _end;
+            end = end > stack.Length ? stack.Length : end;
+
+            // If the stack window is invalid
+            if (end < _start)
                 return -1;
 
-            // If the needle and stack are identically sized, short-circuit
-            if (Needle.Length == stack.Length)
-                return EqualAt(stack, 0) ? 0 : -1;
+            // If the needle is larger than the stack window, it can't be contained within
+            if (Needle.Length > stack.Length - _start)
+                return -1;
+
+            // If the needle and stack window are identically sized, short-circuit
+            if (Needle.Length == stack.Length - _start)
+                return EqualAt(stack, _start) ? _start : -1;
 
             // Return based on the direction of search
             return reverse ? MatchReverse(stack) : MatchForward(stack);
@@ -202,13 +210,21 @@ namespace SabreTools.Matching.Content
             if (stack == null || stack.Length == 0 || Needle.Length == 0)
                 return -1;
 
-            // If the needle array is larger than the stack array, it can't be contained within
-            if (Needle.Length > stack.Length)
+            // Get the adjusted end value for comparison
+            int end = _end < 0 ? (int)stack.Length : _end;
+            end = end > (int)stack.Length ? (int)stack.Length : end;
+
+            // If the stack window is invalid
+            if (end < _start)
                 return -1;
 
-            // If the needle and stack are identically sized, short-circuit
-            if (Needle.Length == stack.Length)
-                return EqualAt(stack, 0) ? 0 : -1;
+            // If the needle is larger than the stack window, it can't be contained within
+            if (Needle.Length > stack.Length - _start)
+                return -1;
+
+            // If the needle and stack window are identically sized, short-circuit
+            if (Needle.Length == stack.Length - _start)
+                return EqualAt(stack, _start) ? _start : -1;
 
             // Return based on the direction of search
             return reverse ? MatchReverse(stack) : MatchForward(stack);

SabreTools.Matching/Extensions.cs

@@ -4,6 +4,7 @@ using SabreTools.Matching.Content;
 
 namespace SabreTools.Matching
 {
+    // TODO: Write SequenceEqual equivilent: EqualsExactly
     public static class Extensions
     {
         /// <summary>
@@ -31,16 +32,24 @@ namespace SabreTools.Matching
             // Get the outgoing list
             List<int> positions = [];
 
-            // Validate the start and end values
-            if (start < 0 || start >= stack.Length)
+            // If either set is null or empty
+            if (stack.Length == 0 || needle.Length == 0)
                 return positions;
-            if (end < -1 || (end != -1 && end < start) || end > stack.Length)
+
+            // If the needle is longer than the stack
+            if (needle.Length > stack.Length)
                 return positions;
 
             // Normalize the end value, if necessary
             if (end == -1)
                 end = stack.Length;
 
+            // Validate the start and end values
+            if (start < 0 || start >= stack.Length)
+                return positions;
+            if (end < -1 || end < start || end > stack.Length)
+                return positions;
+
             // Loop while there is data to check
             while (start < end)
             {
@@ -54,7 +63,7 @@ namespace SabreTools.Matching
 
                 // Append the position and reset the start index
                 positions.Add(position);
-                start = position;
+                start = position + 1;
             }
 
             return positions;
@@ -82,6 +91,14 @@ namespace SabreTools.Matching
         /// <param name="end">Optional ending position in the stack, defaults to -1 (length of stack)</param>
         public static int FirstPosition(this byte[] stack, byte?[] needle, int start = 0, int end = -1)
         {
+            // If either set is null or empty
+            if (stack.Length == 0 || needle.Length == 0)
+                return -1;
+
+            // If the needle is longer than the stack
+            if (needle.Length > stack.Length)
+                return -1;
+
             var matcher = new ContentMatch(needle, start, end);
             return matcher.Match(stack, reverse: false);
         }
@@ -108,6 +125,14 @@ namespace SabreTools.Matching
         /// <param name="end">Optional ending position in the stack, defaults to -1 (length of stack)</param>
         public static int LastPosition(this byte[] stack, byte?[] needle, int start = 0, int end = -1)
         {
+            // If either set is null or empty
+            if (stack.Length == 0 || needle.Length == 0)
+                return -1;
+
+            // If the needle is longer than the stack
+            if (needle.Length > stack.Length)
+                return -1;
+
             var matcher = new ContentMatch(needle, start, end);
             return matcher.Match(stack, reverse: true);
         }