[ci skip] fully destroy immutable Scripts upon Dispose (by making the backing arrays null)

Author: GreemDev

src/Lib/Internal/ExecutableScript.cs

@@ -14,7 +14,7 @@ public abstract class ExecutableScript : IDisposable
 
     public ref readonly byte this[int idx] => ref GetByteAt(idx);
 
-    public bool IsDisposed { get; protected set; }
+    public virtual bool IsDisposed { get; protected set; }
 
     public int GetMasked(int idx) => GetByteAt(idx) & 0xFF;
 

src/Lib/Public/Entities/Script.cs

@@ -1,20 +1,28 @@
-using Starscript.Internal;
+using System.Diagnostics.CodeAnalysis;
+using Starscript.Internal;
 
 namespace Starscript;
 
 public class Script : ExecutableScript
 {
-    private byte[] _code;
-    private Value[] _constants;
+    private byte[]? _code;
+    private Value[]? _constants;
 
-    public override ReadOnlySpan<byte> Code => _code;
+    [MemberNotNullWhen(false, nameof(_code), nameof(_constants))]
+    public override bool IsDisposed { get; protected set; }
 
-    public override ReadOnlySpan<Value> Constants => _constants;
+    public override ReadOnlySpan<byte> Code => _code
+                                               ?? throw new ObjectDisposedException(nameof(Script),
+                                                   "Cannot access bytecode of a disposed Script.");
+
+    public override ReadOnlySpan<Value> Constants => _constants
+                                                     ?? throw new ObjectDisposedException(nameof(Script),
+                                                         "Cannot access constants of a disposed Script.");
 
     public Script(byte[] codeBuffer, Value[] constants)
     {
-        _code = codeBuffer;
-        _constants = constants;
+        _code = codeBuffer ?? throw new NullReferenceException($"Cannot initialize a {nameof(Script)} with a null bytecode buffer.");
+        _constants = constants ?? throw new NullReferenceException($"Cannot initialize a {nameof(Script)} with a null constants buffer.");
     }
 
     protected override ref readonly byte GetByteAt(int idx)
@@ -29,16 +37,19 @@ public override void Dispose()
     {
         if (IsDisposed)
             throw new ObjectDisposedException(nameof(Script), "Cannot dispose an already disposed Script.");
-        
+
         Array.Resize(ref _code, 0);
         Array.Resize(ref _constants, 0);
 
+        _code = null;
+        _constants = null;
+
 #if DEBUG
         Compiler.DebugLog("Destroyed script");
 #endif
 
         IsDisposed = true;
-        
+
         GC.SuppressFinalize(this);
     }
 }