diff --git a/src/test/java/com/diamonddagger590/mccore/database/table/impl/TableVersionHistoryDAOTest.java b/src/test/java/com/diamonddagger590/mccore/database/table/impl/TableVersionHistoryDAOTest.java
index b92fc8f..54ad6f7 100644
--- a/src/test/java/com/diamonddagger590/mccore/database/table/impl/TableVersionHistoryDAOTest.java
+++ b/src/test/java/com/diamonddagger590/mccore/database/table/impl/TableVersionHistoryDAOTest.java
@@ -219,5 +219,19 @@ void updateTable_performsNoUpdate_whenVersionIsAboveCurrent() throws SQLExceptio
             verify(mockStatement).setString(1, "table_history");
             verify(mockStatement, never()).executeUpdate();
         }
+
+        @Test
+        @DisplayName("Given the stored version is negative, when updateTable is called, then no version-0 update is performed")
+        void updateTable_skipsVersionZeroUpdate_whenVersionIsNegative() throws SQLException {
+            when(mockConnection.prepareStatement(anyString())).thenReturn(mockStatement);
+            when(mockStatement.executeQuery()).thenReturn(mockResultSet);
+            when(mockResultSet.next()).thenReturn(true, false);
+            when(mockResultSet.getInt("table_version")).thenReturn(-1);
+
+            TableVersionHistoryDAO.updateTable(mockConnection);
+
+            verify(mockStatement).setString(1, "table_history");
+            verify(mockStatement, never()).executeUpdate();
+        }
     }
 }
diff --git a/src/test/java/com/diamonddagger590/mccore/gui/PaginatedGuiTest.java b/src/test/java/com/diamonddagger590/mccore/gui/PaginatedGuiTest.java
index dd9c74f..d1d39da 100644
--- a/src/test/java/com/diamonddagger590/mccore/gui/PaginatedGuiTest.java
+++ b/src/test/java/com/diamonddagger590/mccore/gui/PaginatedGuiTest.java
@@ -189,6 +189,15 @@ void setPage_throwsForNegativePage() {
 
             assertThrows(IllegalArgumentException.class, () -> gui.setPage(-1));
         }
+
+        @Test
+        @DisplayName("Given max page is 0, when setPage to 1, then throws IllegalArgumentException")
+        void setPage_throwsForMaxPageBelowOne() {
+            TestPaginatedGui gui = new TestPaginatedGui(player, mockInventory, 0);
+            gui.getInventory();
+
+            assertThrows(IllegalArgumentException.class, () -> gui.setPage(1));
+        }
     }
 
     @Nested
diff --git a/src/test/java/com/diamonddagger590/mccore/parser/FunctionNodeTest.java b/src/test/java/com/diamonddagger590/mccore/parser/FunctionNodeTest.java
index 4ce3b74..d120b30 100644
--- a/src/test/java/com/diamonddagger590/mccore/parser/FunctionNodeTest.java
+++ b/src/test/java/com/diamonddagger590/mccore/parser/FunctionNodeTest.java
@@ -271,4 +271,13 @@ void toString_addsParens_whenDoubleNegation() {
         FunctionNode inner = new FunctionNode(c(5.0), 0);
         assertEquals("-(-5)", new FunctionNode(inner, 0).toString());
     }
+
+    // ── getValue default switch branch ────────────────────────────────────
+
+    @Test
+    @DisplayName("Given an out-of-range function index, when evaluating, then returns 0")
+    void getValue_returnsZero_whenFunctionIndexIsOutOfRange() {
+        FunctionNode node = new FunctionNode(c(5.0), FunctionNode.FUNCTIONS.length);
+        assertEquals(0.0, node.getValue(), DELTA);
+    }
 }
diff --git a/src/test/java/com/diamonddagger590/mccore/parser/OperatorNodeTest.java b/src/test/java/com/diamonddagger590/mccore/parser/OperatorNodeTest.java
index d191015..cc09f41 100644
--- a/src/test/java/com/diamonddagger590/mccore/parser/OperatorNodeTest.java
+++ b/src/test/java/com/diamonddagger590/mccore/parser/OperatorNodeTest.java
@@ -404,4 +404,24 @@ void toString_addsBrackets_whenDivisionWithDivisionLeft() {
         OperatorNode node = new OperatorNode(left, c(4.0), '/');
         assertEquals("(8/2)/4", node.toString());
     }
+
+    // ── getValue default switch branch ────────────────────────────────────
+
+    @Test
+    @DisplayName("Given an unsupported operator character, when evaluating, then returns 0")
+    void getValue_returnsZero_whenOperatorIsUnsupported() {
+        OperatorNode node = new OperatorNode(c(3.0), c(4.0), '!');
+        assertEquals(0.0, node.getValue(), DELTA);
+    }
+
+    // ── needBrackets default switch branch ────────────────────────────────
+
+    @Test
+    @DisplayName("Given an unsupported operator with operator children, when converting to string, then adds brackets")
+    void toString_addsBrackets_whenOperatorIsUnsupported() {
+        OperatorNode left = new OperatorNode(c(1.0), c(2.0), '+');
+        OperatorNode right = new OperatorNode(c(3.0), c(4.0), '*');
+        OperatorNode node = new OperatorNode(left, right, '!');
+        assertEquals("(1+2)!(3*4)", node.toString());
+    }
 }