From 6aafab47a24f426f0ef83740b6e9587035461897 Mon Sep 17 00:00:00 2001
From: NikolajDanger <nikolaj@ingemanngade.net>
Date: Wed, 1 Apr 2026 15:56:27 +0200
Subject: [PATCH] :goat: Conditions have to be bools

---
 centvrion/ast_nodes.py |  6 ++++++
 tests.py               | 38 ++++++++++++--------------------------
 2 files changed, 18 insertions(+), 26 deletions(-)

diff --git a/centvrion/ast_nodes.py b/centvrion/ast_nodes.py
index fda4716..a732b14 100644
--- a/centvrion/ast_nodes.py
+++ b/centvrion/ast_nodes.py
@@ -679,6 +679,8 @@ class SiStatement(Node):
 
   def _eval(self, vtable):
     vtable, cond = self.test.eval(vtable)
+    if not isinstance(cond, ValBool):
+      raise CentvrionError("SI condition must be a boolean")
     last_val = ValNul()
     if cond:
       for statement in self.statements:
@@ -714,6 +716,8 @@ class DumStatement(Node):
   def _eval(self, vtable):
     last_val = ValNul()
     vtable, cond = self.test.eval(vtable)
+    if not isinstance(cond, ValBool):
+      raise CentvrionError("DVM condition must be a boolean")
     while not cond:
       for statement in self.statements:
         vtable, val = statement.eval(vtable)
@@ -726,6 +730,8 @@ class DumStatement(Node):
       if vtable["#return"] is not None:
         break
       vtable, cond = self.test.eval(vtable)
+      if not isinstance(cond, ValBool):
+        raise CentvrionError("DVM condition must be a boolean")
     return vtable, last_val
 
 
diff --git a/tests.py b/tests.py
index c8f9c98..4e75d45 100644
--- a/tests.py
+++ b/tests.py
@@ -401,6 +401,11 @@ error_tests = [
   ("PER i IN I FACE { DICE(i) }", CentvrionError),                     # PER over non-array
   ("LONGITVDO(I)", CentvrionError),                                    # LONGITVDO on non-array
   ("DESIGNA x VT I\nINVOCA x ()", CentvrionError),                     # invoking a non-function
+  ("SI I TVNC { DESIGNA r VT I }", CentvrionError),                    # non-bool SI condition: int
+  ("DESIGNA z VT I - I\nSI z TVNC { DESIGNA r VT I }", CentvrionError), # non-bool SI condition: zero int
+  ("SI [I] TVNC { DESIGNA r VT I }", CentvrionError),                  # non-bool SI condition: non-empty list
+  ("SI [] TVNC { DESIGNA r VT I }", CentvrionError),                   # non-bool SI condition: empty list
+  ("DESIGNA x VT I\nDVM x FACE {\nDESIGNA x VT x + I\n}", CentvrionError),  # non-bool DVM condition: int
 ]
 
 class TestErrors(unittest.TestCase):
@@ -557,30 +562,10 @@ class TestDiceTypes(unittest.TestCase):
     run_test(self, source, nodes, value, output)
 
 
-# --- SI/DVM: truthiness of non-bool conditions ---
+# --- SI/DVM: boolean condition enforcement ---
 
-truthiness_tests = [
-  # nonzero int is truthy
-  ("SI I TVNC { DESIGNA r VT I } ALVID { DESIGNA r VT II }\nr",
-    Program([], [SiStatement(Numeral("I"), [Designa(ID("r"), Numeral("I"))], [Designa(ID("r"), Numeral("II"))]), ExpressionStatement(ID("r"))]),
-    ValInt(1)),
-  # zero int is falsy
-  ("DESIGNA z VT I - I\nSI z TVNC { DESIGNA r VT I } ALVID { DESIGNA r VT II }\nr",
-    Program([], [
-      Designa(ID("z"), BinOp(Numeral("I"), Numeral("I"), "SYMBOL_MINUS")),
-      SiStatement(ID("z"), [Designa(ID("r"), Numeral("I"))], [Designa(ID("r"), Numeral("II"))]),
-      ExpressionStatement(ID("r")),
-    ]),
-    ValInt(2)),
-  # non-empty list is truthy
-  ("SI [I] TVNC { DESIGNA r VT I } ALVID { DESIGNA r VT II }\nr",
-    Program([], [SiStatement(DataArray([Numeral("I")]), [Designa(ID("r"), Numeral("I"))], [Designa(ID("r"), Numeral("II"))]), ExpressionStatement(ID("r"))]),
-    ValInt(1)),
-  # empty list is falsy
-  ("SI [] TVNC { DESIGNA r VT II } ALVID { DESIGNA r VT I }\nr",
-    Program([], [SiStatement(DataArray([]), [Designa(ID("r"), Numeral("II"))], [Designa(ID("r"), Numeral("I"))]), ExpressionStatement(ID("r"))]),
-    ValInt(1)),
-  # DVM exits when condition becomes truthy
+dvm_bool_condition_tests = [
+  # DVM exits when condition becomes true (boolean comparison)
   (
     "DESIGNA x VT I\nDVM x PLVS III FACE {\nDESIGNA x VT x + I\n}\nx",
     Program([], [
@@ -592,12 +577,13 @@ truthiness_tests = [
   ),
 ]
 
-class TestTruthiness(unittest.TestCase):
-  @parameterized.expand(truthiness_tests)
-  def test_truthiness(self, source, nodes, value):
+class TestDvmBoolCondition(unittest.TestCase):
+  @parameterized.expand(dvm_bool_condition_tests)
+  def test_dvm_bool_condition(self, source, nodes, value):
     run_test(self, source, nodes, value)
 
 
+
 # --- Arithmetic: edge cases ---
 
 arithmetic_edge_tests = [