diff --git a/src/btree.rs b/src/btree.rs
index 42dd4b5..10c79e7 100644
--- a/src/btree.rs
+++ b/src/btree.rs
@@ -194,3 +194,288 @@ where
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::record::Record;
+    use crate::storage::InMemoryStorage;
+
+    // Helper function to generate a large number of keys and values
+    fn generate_large_dataset(size: usize) -> (Vec<i32>, Vec<Record>) {
+        let keys: Vec<i32> = (1..=size as i32).collect();
+        let values: Vec<Record> = keys.iter().map(|&k| [k; 6]).collect();
+        (keys, values)
+    }
+
+    // Helper function to generate random keys and values
+    fn generate_random_dataset(size: usize) -> (Vec<i32>, Vec<Record>) {
+        use rand::Rng;
+        let mut rng = rand::rng();
+        let keys: Vec<i32> = (0..size).map(|_| rng.random_range(1..10000)).collect();
+        let values: Vec<Record> = keys.iter().map(|&k| [k; 6]).collect();
+        (keys, values)
+    }
+
+    #[test]
+    fn test_initialization() {
+        let storage = InMemoryStorage::new();
+        let tree = BPlusTree::open(storage);
+        assert_eq!(tree.root_loc, 0);
+    }
+
+    #[test]
+    fn test_insert_and_find() {
+        let storage = InMemoryStorage::new();
+        let mut tree = BPlusTree::open(storage);
+        let key = 1;
+        let value = [1, 2, 3, 4, 5, 6]; // Example Record as [i32; 6]
+        tree.insert(key, value);
+        assert_eq!(tree.find(key), Some(value));
+    }
+
+    #[test]
+    fn test_multiple_inserts_and_finds() {
+        let storage = InMemoryStorage::new();
+        let mut tree = BPlusTree::open(storage);
+        let keys = [1, 2, 3, 4, 5];
+        let values = [
+            [1, 2, 3, 4, 5, 6],
+            [7, 8, 9, 10, 11, 12],
+            [13, 14, 15, 16, 17, 18],
+            [19, 20, 21, 22, 23, 24],
+            [25, 26, 27, 28, 29, 30],
+        ];
+        for (i, key) in keys.iter().enumerate() {
+            tree.insert(*key, values[i]);
+        }
+        for (i, key) in keys.iter().enumerate() {
+            assert_eq!(tree.find(*key), Some(values[i]));
+        }
+    }
+
+    #[test]
+    fn test_leaf_split() {
+        let storage = InMemoryStorage::new();
+        let mut tree = BPlusTree::open(storage);
+        let keys = [1, 2, 3, 4, 5]; // Assuming MAX_KEYS is 4, this will trigger a split
+        let values = [
+            [1, 2, 3, 4, 5, 6],
+            [7, 8, 9, 10, 11, 12],
+            [13, 14, 15, 16, 17, 18],
+            [19, 20, 21, 22, 23, 24],
+            [25, 26, 27, 28, 29, 30],
+        ];
+        for (i, key) in keys.iter().enumerate() {
+            tree.insert(*key, values[i]);
+        }
+        // Verify that all keys can still be found after splits
+        for (i, key) in keys.iter().enumerate() {
+            assert_eq!(tree.find(*key), Some(values[i]));
+        }
+    }
+
+    #[test]
+    fn test_internal_split() {
+        let storage = InMemoryStorage::new();
+        let mut tree = BPlusTree::open(storage);
+        // Insert enough keys to trigger internal splits
+        let keys = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+        let values = [
+            [1, 2, 3, 4, 5, 6],
+            [7, 8, 9, 10, 11, 12],
+            [13, 14, 15, 16, 17, 18],
+            [19, 20, 21, 22, 23, 24],
+            [25, 26, 27, 28, 29, 30],
+            [31, 32, 33, 34, 35, 36],
+            [37, 38, 39, 40, 41, 42],
+            [43, 44, 45, 46, 47, 48],
+            [49, 50, 51, 52, 53, 54],
+            [55, 56, 57, 58, 59, 60],
+            [61, 62, 63, 64, 65, 66],
+        ];
+        for (i, key) in keys.iter().enumerate() {
+            tree.insert(*key, values[i]);
+        }
+        // Verify that all keys can still be found after splits
+        for (i, key) in keys.iter().enumerate() {
+            assert_eq!(tree.find(*key), Some(values[i]));
+        }
+    }
+
+    #[test]
+    fn test_update() {
+        let storage = InMemoryStorage::new();
+        let mut tree = BPlusTree::open(storage);
+        let key = 1;
+        let initial_value = [1, 2, 3, 4, 5, 6];
+        let updated_value = [7, 8, 9, 10, 11, 12];
+        tree.insert(key, initial_value);
+        assert_eq!(tree.find(key), Some(initial_value));
+        tree.insert(key, updated_value);
+        assert_eq!(tree.find(key), Some(updated_value));
+    }
+
+    #[test]
+    fn test_non_existent_key() {
+        let storage = InMemoryStorage::new();
+        let tree = BPlusTree::open(storage);
+        assert_eq!(tree.find(999), None); // Assuming 999 is not in the tree
+    }
+
+    #[test]
+    fn test_out_of_order_inserts() {
+        let storage = InMemoryStorage::new();
+        let mut tree = BPlusTree::open(storage);
+        let keys = [5, 3, 1, 4, 2];
+        let values = [
+            [1, 2, 3, 4, 5, 6],
+            [7, 8, 9, 10, 11, 12],
+            [13, 14, 15, 16, 17, 18],
+            [19, 20, 21, 22, 23, 24],
+            [25, 26, 27, 28, 29, 30],
+        ];
+        for (i, key) in keys.iter().enumerate() {
+            tree.insert(*key, values[i]);
+        }
+        // Verify that all keys can be found
+        for (i, key) in keys.iter().enumerate() {
+            assert_eq!(tree.find(*key), Some(values[i]));
+        }
+    }
+
+    #[test]
+    fn test_large_number_of_inserts() {
+        let storage = InMemoryStorage::new();
+        let mut tree = BPlusTree::open(storage);
+        let num_keys = 100;
+        let keys: Vec<i32> = (1..=num_keys).collect();
+        let values: Vec<Record> = (1..=num_keys)
+            .map(|i| [i, i + 1, i + 2, i + 3, i + 4, i + 5])
+            .collect();
+        for (i, key) in keys.iter().enumerate() {
+            tree.insert(*key, values[i]);
+        }
+        // Verify that all keys can be found
+        for (i, key) in keys.iter().enumerate() {
+            assert_eq!(tree.find(*key), Some(values[i]));
+        }
+    }
+
+    #[test]
+    fn test_duplicate_keys() {
+        let storage = InMemoryStorage::new();
+        let mut tree = BPlusTree::open(storage);
+        let key = 1;
+        let initial_value = [1, 2, 3, 4, 5, 6];
+        let updated_value = [7, 8, 9, 10, 11, 12];
+        tree.insert(key, initial_value);
+        assert_eq!(tree.find(key), Some(initial_value));
+        tree.insert(key, updated_value);
+        assert_eq!(tree.find(key), Some(updated_value));
+    }
+
+    #[test]
+    fn test_recursive_splitting_up_to_root() {
+        let storage = InMemoryStorage::new();
+        let mut tree = BPlusTree::open(storage);
+
+        // Insert enough keys to cause multiple splits, including root split
+        let keys = (1..=20).collect::<Vec<i32>>();
+        let values: Vec<Record> = keys.iter().map(|&k| [k; 6]).collect();
+
+        for (i, key) in keys.iter().enumerate() {
+            tree.insert(*key, values[i]);
+        }
+
+        // Verify all keys are present
+        for (i, key) in keys.iter().enumerate() {
+            assert_eq!(tree.find(*key), Some(values[i]));
+        }
+    }
+
+    #[test]
+    fn test_large_dataset() {
+        let storage = InMemoryStorage::new();
+        let mut tree = BPlusTree::open(storage);
+        let (keys, values) = generate_large_dataset(10000);
+
+        for (i, key) in keys.iter().enumerate() {
+            tree.insert(*key, values[i]);
+        }
+
+        // Verify all keys are present
+        for (i, key) in keys.iter().enumerate() {
+            assert_eq!(tree.find(*key), Some(values[i]));
+        }
+    }
+
+    #[test]
+    fn test_boundary_values() {
+        let storage = InMemoryStorage::new();
+        let mut tree = BPlusTree::open(storage);
+
+        // Test with minimum and maximum i32 values
+        let min_key = i32::MIN;
+        let max_key = i32::MAX;
+        let min_value = [i32::MIN; 6];
+        let max_value = [i32::MAX; 6];
+
+        tree.insert(min_key, min_value);
+        tree.insert(max_key, max_value);
+
+        assert_eq!(tree.find(min_key), Some(min_value));
+        assert_eq!(tree.find(max_key), Some(max_value));
+    }
+
+    #[test]
+    fn test_sequential_insertions() {
+        let storage = InMemoryStorage::new();
+        let mut tree = BPlusTree::open(storage);
+        let (keys, values) = generate_large_dataset(100);
+
+        for (i, key) in keys.iter().enumerate() {
+            tree.insert(*key, values[i]);
+        }
+
+        // Verify all keys are present
+        for (i, key) in keys.iter().enumerate() {
+            assert_eq!(tree.find(*key), Some(values[i]));
+        }
+    }
+
+    #[test]
+    fn test_random_insertions() {
+        let storage = InMemoryStorage::new();
+        let mut tree = BPlusTree::open(storage);
+        let (keys, values) = generate_random_dataset(100);
+
+        for (i, key) in keys.iter().enumerate() {
+            tree.insert(*key, values[i]);
+        }
+
+        // Verify all keys are present
+        for (i, key) in keys.iter().enumerate() {
+            assert_eq!(tree.find(*key), Some(values[i]));
+        }
+    }
+
+    #[test]
+    fn test_node_splitting_and_balance() {
+        let storage = InMemoryStorage::new();
+        let mut tree = BPlusTree::open(storage);
+
+        // Insert keys that will cause multiple splits
+        let keys = (1..=50).collect::<Vec<i32>>();
+        let values: Vec<Record> = keys.iter().map(|&k| [k; 6]).collect();
+
+        for (i, key) in keys.iter().enumerate() {
+            tree.insert(*key, values[i]);
+        }
+
+        // Verify all keys are present and tree is balanced
+        for (i, key) in keys.iter().enumerate() {
+            assert_eq!(tree.find(*key), Some(values[i]));
+        }
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index 3712f0b..bc7649e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -6,7 +6,7 @@ use crate::btree::BPlusTree;
 use crate::storage::InMemoryStorage;
 
 fn main() {
-    let storage = InMemoryStorage { nodes: Vec::new() };
+    let storage = InMemoryStorage::new();
     let mut tree = BPlusTree::open(storage);
 
     // Insert some key-value pairs
diff --git a/src/storage.rs b/src/storage.rs
index fa7e077..78862cf 100644
--- a/src/storage.rs
+++ b/src/storage.rs
@@ -11,6 +11,12 @@ pub struct InMemoryStorage {
     pub nodes: Vec<Option<Node>>,
 }
 
+impl InMemoryStorage {
+    pub fn new() -> Self {
+        Self { nodes: Vec::new() }
+    }
+}
+
 impl Storage for InMemoryStorage {
     fn read_node(&self, loc: usize) -> Option<Node> {
         self.nodes.get(loc)?.clone()