From fcec637f01c89b3a5f3ee92e72fbbc1b2c4c091f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20M=C3=BCller?= <thomas.mi.iller.gitea.tmu@gmail.com>
Date: Tue, 22 Sep 2026 10:36:03 +0000
Subject: [PATCH] :white_check_mark: Check the runtime member in every
 boolean/nullish handler

---
 src/tagged-union.test.ts | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/tagged-union.test.ts b/src/tagged-union.test.ts
index e3e1d26..7873b81 100644
--- a/src/tagged-union.test.ts
+++ b/src/tagged-union.test.ts
@@ -216,8 +216,22 @@ test("getTaggedUnionMatcherW: boolean and nullish tags widen to the union", () =
             assert.equal(s.kind, true);
             return "yes" as const;
         },
-        false: () => 0 as const,
-        null: () => null,
+        false: (s) => {
+            expectTypeOf(s).toEqualTypeOf<{
+                readonly kind: false;
+                readonly b: number;
+            }>();
+            assert.equal(s.kind, false);
+            return 0 as const;
+        },
+        null: (s) => {
+            expectTypeOf(s).toEqualTypeOf<{
+                readonly kind: null;
+                readonly c: number;
+            }>();
+            assert.equal(s.kind, null);
+            return null;
+        },
     });
 
     // Assert