Adds check for local variable in scope operator check

Content.Tests/DMProject/Tests/Operators/scope.dm

@@ -1,15 +1,15 @@
 /datum
 	var/static/datum/three/three
 	var/text = "hello"
-	
+
 var/static/one = "one"
 
 /datum/three
 	var/static/datum/four/four
 	text = "hi"
 	var/overridden_text = type::text
 	var/original_text = parent_type::text
-	
+
 /datum/three/proc/typetest()
 	// initial shorthand, type:: and parent_type::
 	ASSERT(text == "hi")
@@ -21,7 +21,7 @@ var/static/one = "one"
 	ASSERT(src::text == "hi")
 	ASSERT(src::overridden_text == "hi")
 	ASSERT(src::original_text == "hello")
-	
+
 	// proc reference
 	ASSERT(__PROC__ == /datum/three::typetest())
 
@@ -31,11 +31,17 @@ var/static/one = "one"
 /datum/five
 	var/static/six = "three four five six"
 
+/datum/six
+	var/price = 60
+	better
+		price = parent_type::price + 40
+
 /proc/return_two()
 	return "two"
 
 /proc/RunTest()
 	// global vars and procs
+	var/one = "not one"
 	ASSERT(::one == "one")
 	ASSERT(::return_two() == "two")
 
@@ -52,10 +58,13 @@ var/static/one = "one"
 	ASSERT(test::three::four.five::six == "3 4 5 6")
 	ASSERT(/datum::three::four.five::six == "3 4 5 6")
 
-	// this does not compile in BYOND, that is just a bug 
+	// this does not compile in BYOND, that is just a bug
 	test::three::four.five::six = "7 8 9 10"
 	ASSERT(test::three::four.five::six == "7 8 9 10")
 	ASSERT(/datum::three::four.five::six == "7 8 9 10")
-	
+
 	var/datum/three/threetest = new
 	threetest.typetest()
+
+	var/datum/six/better/fourtest = new()
+	ASSERT(fourtest.price == 100)

Content.Tests/DMProject/Tests/Operators/scope_parent_type_fails.dm

@@ -0,0 +1,7 @@
+// COMPILE ERROR OD0011
+
+/datum/thing
+	var/price = 60
+	better
+		proc/test_proc()
+			price = parent_type::price + 40

DMCompiler/DM/Builders/DMExpressionBuilder.cs

@@ -644,11 +644,16 @@ private DMExpression BuildScopeIdentifier(DMASTScopeIdentifier scopeIdentifier,
         if (scopeIdentifier.Expression is DMASTIdentifier { Identifier: "type" or "parent_type" } identifier) {
             // This is the same behaviour as in BYOND, but BYOND simply raises an undefined var error.
             // We want to give end users an explanation at least.
-            if (scopeMode is Normal && ctx.Proc != null)
-                return BadExpression(WarningCode.BadExpression, identifier.Location,
-                    "Use of \"type::\" and \"parent_type::\" outside of a context is forbidden");
-
-            if (identifier.Identifier == "parent_type") {
+            if (scopeMode is Normal && ctx.Proc != null) {
+                if (ctx.Proc.GetLocalVariable(identifier.Identifier) != null) {
+                    // actually - it's referring to a local variable named "type" or "parent_type"... just do the usual thing
+                    expression = BuildExpression(scopeIdentifier.Expression, inferredPath);
+                } else {
+                    return BadExpression(WarningCode.BadExpression, identifier.Location,
+                            "Use of \"type::\" and \"parent_type::\" inside an object proc is only valid when " +
+                            "there is a local variable named \"type\" or \"parent_type\"");
+                }
+            } else if (identifier.Identifier == "parent_type") {
                 if (ctx.Type.Parent == null)
                     return BadExpression(WarningCode.ItemDoesntExist, identifier.Location,
                         $"Type {ctx.Type.Path} does not have a parent");

DMCompiler/DM/DMExpression.cs

@@ -138,10 +138,10 @@ private void VerifyArgType(DMCompiler compiler, DMProc targetProc, int index, st
     }
 }
 
-internal readonly struct ExpressionContext(DMCompiler compiler, DMObject type, DMProc proc) {
+internal readonly struct ExpressionContext(DMCompiler compiler, DMObject type, DMProc? proc) {
     public readonly DMCompiler Compiler = compiler;
     public readonly DMObject Type = type;
-    public readonly DMProc Proc = proc;
+    public readonly DMProc? Proc = proc;
 
     public DMObjectTree ObjectTree => Compiler.DMObjectTree;
 }