flow fix, unit tests, reword error

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())
 
@@ -34,6 +34,11 @@ var/static/one = "one"
 /proc/return_two()
 	return "two"
 
+/datum/six
+	var/price = 60
+	better
+		price = parent_type::price + 40
+
 /proc/RunTest()
 	// global vars and procs
 	ASSERT(::one == "one")
@@ -52,10 +57,12 @@ 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/test

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

@@ -0,0 +1,10 @@
+// COMPILE ERROR OD0011
+
+/datum/thing
+	var/price = 60
+	better
+		proc/test_proc()
+			price = parent_type::price + 40
+
+/proc/RunTest()
+	var/datum/thing/better/test

DMCompiler/DM/Builders/DMExpressionBuilder.cs

@@ -644,16 +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)
+            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::\" outside of a context is forbidden");
+                            "Use of \"type::\" and \"parent_type::\" inside an object proc is only valid when " +
+                            "there is a local variable named \"type\" or \"parent_type\"");
                 }
-
-            if (identifier.Identifier == "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");