Complete overhaul on Skippers

This change involves safety updates for serialization, better definitions of various classes, renames of some classes for accuracy, missing enum decoration, and various fixes.

SabreTools.Skippers/Tests/AndTest.cs

@@ -0,0 +1,130 @@
+using System;
+using System.IO;
+using System.Xml;
+using System.Xml.Serialization;
+
+namespace SabreTools.Skippers.Tests
+{
+    /// <summary>
+    /// Test that uses a byte mask AND against data
+    /// </summary>
+    [XmlType("and")]
+    public class AndTest : Test
+    {
+        #region Fields
+
+        /// <summary>
+        /// File offset to run the test
+        /// </summary>
+        /// <remarks>Either numeric or the literal "EOF"</remarks>
+        [XmlAttribute("offset")]
+        public string? Offset
+        {
+            get => _offset == null ? "EOF" : _offset.Value.ToString();
+            set
+            {
+                if (value == null || value.ToLowerInvariant() == "eof")
+                    _offset = null;
+                else
+                    _offset = Convert.ToInt64(value, fromBase: 16);
+            }
+        }
+
+        /// <summary>
+        /// Static value to be checked at the offset
+        /// </summary>
+        /// <remarks>Hex string representation of a byte array</remarks>
+        [XmlAttribute("value")]
+        public string? Value
+        {
+            get => _value == null ? string.Empty : BitConverter.ToString(_value).Replace("-", string.Empty);
+            set => _value = ParseByteArrayFromHex(value);
+        }
+
+        /// <summary>
+        /// Determines whether a pass or failure is expected
+        /// </summary>
+        [XmlAttribute("result")]
+        public bool Result { get; set; } = true;
+
+        /// <summary>
+        /// Byte mask to be applied to the tested bytes
+        /// </summary>
+        /// <remarks>Hex string representation of a byte array</remarks>
+        [XmlAttribute("mask")]
+        public string? Mask
+        {
+            get => _mask == null ? string.Empty : BitConverter.ToString(_mask).Replace("-", string.Empty);
+            set => _mask = ParseByteArrayFromHex(value);
+        }
+
+        #endregion
+
+        #region Private instance variables
+
+        /// <summary>
+        /// File offset to run the test
+        /// </summary>
+        /// <remarks>null is EOF</remarks>
+        private long? _offset;
+
+        /// <summary>
+        /// Static value to be checked at the offset
+        /// </summary>
+        private byte[]? _value;
+
+        /// <summary>
+        /// Byte mask to be applied to the tested bytes
+        /// </summary>
+        private byte[]? _mask;
+
+        #endregion
+
+        /// <inheritdoc/>
+        public override bool Passes(Stream input)
+        {
+            // If we have an invalid mask
+            if (_mask == null || _mask.Length == 0)
+                return false;
+
+            // If we have an invalid value
+            if (_value == null || _value.Length == 0)
+                return false;
+
+            // Seek to the correct position, if possible
+            if (!Seek(input, _offset))
+                return false;
+
+            bool result = true;
+            try
+            {
+                // Then apply the mask if it exists
+                byte[] read = new byte[_mask.Length];
+                input.Read(read, 0, _mask.Length);
+
+                byte[] masked = new byte[_mask.Length];
+                for (int i = 0; i < read.Length; i++)
+                {
+                    masked[i] = (byte)(read[i] & _mask[i]);
+                }
+
+                // Finally, compare it against the value
+                for (int i = 0; i < _value.Length; i++)
+                {
+                    if (masked[i] != _value[i])
+                    {
+                        result = false;
+                        break;
+                    }
+                }
+            }
+            catch
+            {
+                result = false;
+            }
+
+            // Return if the expected and actual results match
+            return result == Result;
+        }
+    }
+}