From 18a1a33d7186aec2a7e4729433914ef01b02731f Mon Sep 17 00:00:00 2001
From: Mark Skelton <mdskelton99@gmail.com>
Date: Sun, 14 Jan 2024 15:55:03 -0600
Subject: [PATCH] fix: treat `undefined` as `false` for boolean variants

---
 src/__tests__/tv.test.ts | 16 ++++++++++++++++
 src/index.js             |  5 ++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/__tests__/tv.test.ts b/src/__tests__/tv.test.ts
index a2cedcf..26195e5 100644
--- a/src/__tests__/tv.test.ts
+++ b/src/__tests__/tv.test.ts
@@ -314,6 +314,22 @@ describe("Tailwind Variants (TV) - Default", () => {
 
     expect(h1({color: "green", isUnderline: false})).toBe(expectedResult);
   });
+
+  test("should treat undefined and false identically for boolean variants", () => {
+    const h1 = tv({
+      base: "text-3xl",
+      variants: {
+        bool: {
+          true: "underline",
+          false: "no-underline",
+        },
+      },
+    });
+
+    expect(h1({bool: true})).toBe("text-3xl underline");
+    expect(h1({bool: false})).toBe("text-3xl no-underline");
+    expect(h1()).toBe("text-3xl no-underline");
+  });
 });
 
 describe("Tailwind Variants (TV) - Slots", () => {
diff --git a/src/index.js b/src/index.js
index 0c90d60..52330fc 100644
--- a/src/index.js
+++ b/src/index.js
@@ -199,7 +199,10 @@ export const tv = (options, configProp) => {
         }
       }
 
-      const value = variantObj[variantKey] || variantObj[falsyToString(defaultVariantProp)];
+      const value =
+        variantObj[variantKey] ||
+        variantObj[falsyToString(defaultVariantProp)] ||
+        variantObj["false"];
 
       if (
         typeof screenValues === "object" &&