enable nullable annotations in the rest of SMAPI core (#837)

1 files changed, 11 insertions, 4 deletions

diff --git a/src/SMAPI/Framework/ModLoading/AssemblyParseResult.cs b/src/SMAPI/Framework/ModLoading/AssemblyParseResult.cs
index 56bd5a8b..b133f8d6 100644
--- a/src/SMAPI/Framework/ModLoading/AssemblyParseResult.cs
+++ b/src/SMAPI/Framework/ModLoading/AssemblyParseResult.cs
@@ -1,5 +1,5 @@
-#nullable disable
-
+using System;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using Mono.Cecil;
 
@@ -15,11 +15,15 @@ namespace StardewModdingAPI.Framework.ModLoading
         public readonly FileInfo File;
 
         /// <summary>The assembly definition.</summary>
-        public readonly AssemblyDefinition Definition;
+        public readonly AssemblyDefinition? Definition;
 
         /// <summary>The result of the assembly load.</summary>
         public AssemblyLoadStatus Status;
 
+        /// <summary>Whether the <see cref="Definition"/> is loaded and ready (i.e. the <see cref="Status"/> is not <see cref="AssemblyLoadStatus.AlreadyLoaded"/> or <see cref="AssemblyLoadStatus.Failed"/>).</summary>
+        [MemberNotNullWhen(true, nameof(AssemblyParseResult.Definition))]
+        public bool HasDefinition => this.Status == AssemblyLoadStatus.Okay;
+
 
         /*********
         ** Public methods
@@ -28,11 +32,14 @@ namespace StardewModdingAPI.Framework.ModLoading
         /// <param name="file">The original assembly file.</param>
         /// <param name="assembly">The assembly definition.</param>
         /// <param name="status">The result of the assembly load.</param>
-        public AssemblyParseResult(FileInfo file, AssemblyDefinition assembly, AssemblyLoadStatus status)
+        public AssemblyParseResult(FileInfo file, AssemblyDefinition? assembly, AssemblyLoadStatus status)
         {
             this.File = file;
             this.Definition = assembly;
             this.Status = status;
+
+            if (status == AssemblyLoadStatus.Okay && assembly == null)
+                throw new InvalidOperationException($"Invalid assembly parse result: load status {status} with a null assembly.");
         }
     }
 }