update view, still work to do

DieHammerTests/Bunch_O__DiceTests.swift

@@ -227,20 +227,30 @@ struct RerollTests {
         #expect(roll.hitHasRerolled == true)
     }
 
-    @Test("applyReroll: guard blocks second call")
-    func applyRerollRespectsFlagAlreadySet() {
+    @Test("applyReroll: re-applying restores snapshot and rerolls with new mode")
+    func applyRerollChangeModeRestoresSnapshot() {
         let roll = Roll()
         roll.state = .hit
+        roll.hitCutoff = .four
+        roll.hitRerollMode = .ones
+        roll.dice.one = 3; roll.dice.six = 2
+        roll.total = 5
+
+        // First reroll: reroll the 3 ones
+        roll.applyReroll()
+        #expect(roll.hitHasRerolled == true)
+        #expect(roll.preRerollDice != nil)
+        let afterFirst = roll.dice.one + roll.dice.two + roll.dice.three +
+                         roll.dice.four + roll.dice.five + roll.dice.six
+        #expect(afterFirst == 5)
+
+        // Switch to 'all' mode — should restore snapshot then reroll all
         roll.hitRerollMode = .all
-        roll.hitHasRerolled = true  // simulate already used
-        roll.dice.one = 5           // known state
-        roll.applyReroll()          // should be blocked by guard
-        #expect(roll.dice.one   == 5)
-        #expect(roll.dice.two   == 0)
-        #expect(roll.dice.three == 0)
-        #expect(roll.dice.four  == 0)
-        #expect(roll.dice.five  == 0)
-        #expect(roll.dice.six   == 0)
+        roll.applyReroll()
+        let afterSecond = roll.dice.one + roll.dice.two + roll.dice.three +
+                          roll.dice.four + roll.dice.five + roll.dice.six
+        #expect(afterSecond == 5)
+        #expect(roll.hitHasRerolled == true)
     }
 
     @Test("applyReroll: only sets flag for the active phase")
@@ -269,6 +279,36 @@ struct RerollTests {
         #expect(roll.dice.six >= 2) // dice above cutoff are untouched; rerolls may also produce sixes
     }
 
+    @Test("undoReroll: restores dice and clears flag")
+    func undoRerollRestoresDice() {
+        let roll = Roll()
+        roll.state = .hit
+        roll.hitCutoff = .four
+        roll.hitRerollMode = .ones
+        roll.dice.one = 3; roll.dice.six = 2
+        roll.total = 5
+
+        roll.applyReroll()
+        #expect(roll.hitHasRerolled == true)
+
+        roll.undoReroll()
+        #expect(roll.hitHasRerolled == false)
+        #expect(roll.preRerollDice == nil)
+        // Dice should be restored to original state
+        #expect(roll.dice.one == 3)
+        #expect(roll.dice.six == 2)
+    }
+
+    @Test("undoReroll: no-op when no reroll has been applied")
+    func undoRerollNoop() {
+        let roll = Roll()
+        roll.state = .hit
+        roll.dice.one = 3
+        roll.undoReroll()  // nothing to undo
+        #expect(roll.dice.one == 3)
+        #expect(roll.hitHasRerolled == false)
+    }
+
     @Test("resetPool: clears hitHasRerolled flag")
     func resetPoolClearsFlag() {
         let roll = Roll()