Adds an exception to 'turn()' on invalid direction types (#2371)

Author: dallaszzz

Content.Tests/DMProject/Tests/Builtins/turn.dm

@@ -51,10 +51,3 @@
 	ASSERT(turn(WEST, -22) == WEST)
 	ASSERT(turn(WEST, -44) == WEST)
 	ASSERT(turn(WEST, -75) == NORTHWEST)
-
-	// An invalid first arg but valid second arg should give a random direction
-	// It's a little hard to test for randomness here, so just verify it's within the range of valid directions
-	var/shouldBeRandomDir = turn(0, 90)
-	ASSERT(shouldBeRandomDir >= 1 && shouldBeRandomDir <= 10)
-	shouldBeRandomDir = turn("NORTH", 90)
-	ASSERT(shouldBeRandomDir >= 1 && shouldBeRandomDir <= 10)

OpenDreamRuntime/Procs/Native/DreamProcNativeRoot.cs

@@ -3107,7 +3107,10 @@ public static DreamValue NativeProc_turn(NativeProc.Bundle bundle, DreamObject?
             return DreamProcNativeMatrix._NativeProc_TurnInternal(bundle.ObjectTree, clonedMatrix, angle);
         }
 
-        dirArg.TryGetValueAsInteger(out int possibleDir);
+        // If Dir is not an integer, throw
+        if (!dirArg.TryGetValueAsInteger(out int possibleDir)) {
+            throw new Exception("expected icon, matrix or integer");
+        }
 
         AtomDirection dir = (AtomDirection)possibleDir;
         float? dirAngle = dir switch {