From cfcd23c4445764bff38bd2c5e2ce253d01c0ad44 Mon Sep 17 00:00:00 2001
From: Nada Amin <namin@alum.mit.edu>
Date: Sat, 11 Jul 2026 16:17:55 -0400
Subject: [PATCH] coerce truthy objects for cond

---
 tools/src/transform.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/src/transform.ts b/tools/src/transform.ts
index 801ed2f..097dbcf 100644
--- a/tools/src/transform.ts
+++ b/tools/src/transform.ts
@@ -335,7 +335,8 @@ function coerceCondToBool(cond: Expr, ty: Ty): Expr {
     return { kind: "binop", op: "≠", left: cond, right: { kind: "num", value: 0 } };
   if (ty.kind === "string")
     return { kind: "binop", op: ">", left: { kind: "field", obj: cond, field: "length" }, right: { kind: "num", value: 0 } };
-  if (ty.kind === "array")
+  // Arrays, objects, maps, sets, tuples are always truthy in JS (even `[]`/`{}`).
+  if (["array", "user", "map", "set", "tuple"].includes(ty.kind))
     return { kind: "bool", value: true };
   return cond;
 }