fix substitution

Author: devpikachu

Common.Build/Config/ProjectConfig.cs

@@ -8,5 +8,5 @@ public class ProjectConfig
     public required string Name { get; init; }
     public required string? ArchiveSuffix { get; init; }
     public required string? OutputSubdirectory { get; init; }
-    public required List<string> SubstitutionTargets { get; init; }
+    public required List<string>? SubstitutionTargets { get; init; }
 }

Common.Build/Tasks/SubstituteTask.cs

@@ -9,11 +9,11 @@ public class SubstituteTask : FrostingTask<BuildContext>
 {
     private const string VersionPlaceholder = "12.34.56";
 
-    public override bool ShouldRun(BuildContext context) => !context.InternalConfig.SkipSubstitution && context.ProjectConfig.SubstitutionTargets.Count != 0;
+    public override bool ShouldRun(BuildContext context) => !context.InternalConfig.SkipSubstitution && (context.ProjectConfig.SubstitutionTargets ?? []).Count != 0;
 
     public override void Run(BuildContext context)
     {
-        foreach (var substitutionTarget in context.ProjectConfig.SubstitutionTargets)
+        foreach (var substitutionTarget in context.ProjectConfig.SubstitutionTargets ?? [])
         {
             var path = Path.Combine("..", context.InternalConfig.Project, substitutionTarget);
             if (!File.Exists(path))

schemas/config.schema.json

@@ -56,7 +56,10 @@
             "minLength": 1
           },
           "substitutionTargets": {
-            "type": "array",
+            "type": [
+              "array",
+              "null"
+            ],
             "description": "A list of relative file paths to perform substitution on.",
             "items": {
               "type": "string",
@@ -68,7 +71,10 @@
       }
     },
     "substitutions": {
-      "type": "object",
+      "type": [
+        "object",
+        "null"
+      ],
       "description": "Key-value pairs of substitution to be performed, in addition to the built-in ones.",
       "additionalProperties": {
         "type": "string"