From 73a58f5893e12da25acda2466576a579663271b6 Mon Sep 17 00:00:00 2001
From: "Joey@macstudio" <4296411@qq.com>
Date: Fri, 17 Jul 2026 00:03:57 +0800
Subject: [PATCH] fix: score duplicate ranks in Four Fingers straights

---
 balatro-sim.js             |  3 ++-
 breakdown.js               |  3 ++-
 tests/four-fingers.test.js | 39 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+), 2 deletions(-)
 create mode 100644 tests/four-fingers.test.js

diff --git a/balatro-sim.js b/balatro-sim.js
index ab5cc9b..a093925 100644
--- a/balatro-sim.js
+++ b/balatro-sim.js
@@ -1097,7 +1097,8 @@ class Hand {
       }
 
       if(lines[lines.length - 1].length >= (this.FourFingers ? 4 : 5)) {
-        straight = lines[lines.length - 1];
+        const straightRanks = new Set(lines[lines.length - 1].map(card => card[RANK]));
+        straight = sortedCards.filter(card => straightRanks.has(card[RANK]));
       }
     }
 
diff --git a/breakdown.js b/breakdown.js
index 9b64f7b..e50ceaf 100644
--- a/breakdown.js
+++ b/breakdown.js
@@ -1514,7 +1514,8 @@ class Hand {
       }
 
       if(lines[lines.length - 1].length >= (this.FourFingers ? 4 : 5)) {
-        straight = lines[lines.length - 1];
+        const straightRanks = new Set(lines[lines.length - 1].map(card => card[RANK]));
+        straight = sortedCards.filter(card => straightRanks.has(card[RANK]));
       }
     }
 
diff --git a/tests/four-fingers.test.js b/tests/four-fingers.test.js
new file mode 100644
index 0000000..9cc7ef8
--- /dev/null
+++ b/tests/four-fingers.test.js
@@ -0,0 +1,39 @@
+"use strict";
+
+const assert = require("node:assert/strict");
+const fs = require("node:fs");
+const path = require("node:path");
+const test = require("node:test");
+const vm = require("node:vm");
+
+function loadHand(sourceFile) {
+  const context = vm.createContext({});
+  const source = fs.readFileSync(path.join(__dirname, "..", sourceFile), "utf8");
+  vm.runInContext(source, context, { filename: sourceFile });
+  return vm.runInContext("Hand", context);
+}
+
+function card(rank, suit) {
+  return [rank, suit, 0, 0, 0, 0, false, 0, 0];
+}
+
+for(const sourceFile of ["balatro-sim.js", "breakdown.js"]) {
+  test(`${sourceFile} scores duplicate ranks in a Four Fingers straight`, () => {
+    const Hand = loadHand(sourceFile);
+    const cards = [
+      card(0, 0),
+      card(1, 1),
+      card(1, 2),
+      card(2, 3),
+      card(3, 0)
+    ];
+    const hand = new Hand({ cards });
+    hand.FourFingers = true;
+
+    const [handType, involvedCards] = hand.getTypeOfHand();
+    const involvedRanks = Array.from(involvedCards, involvedCard => involvedCard[0]).sort((a, b) => a - b);
+
+    assert.equal(handType, 7);
+    assert.deepEqual(involvedRanks, [0, 1, 1, 2, 3]);
+  });
+}