Hasher with SHA256 algorithm is no more the default

3 files changed, 26 insertions, 11 deletions

diff --git a/Cargo.toml b/Cargo.toml
index 95acfdf..e28f8ce 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,5 +5,9 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
-hex = "0.4.3"
-sha2 = "0.10.9"
+hex = { version = "0.4.3", optional = true }
+sha2 = { version = "0.10.9", optional = true }
+
+[features]
+default = []
+sha256 = ["sha2", "hex"]
diff --git a/src/hasher.rs b/src/hasher.rs
index 028e73a..898393f 100644
--- a/src/hasher.rs
+++ b/src/hasher.rs
@@ -1,3 +1,4 @@
+#[cfg(feature = "sha256")]
 use sha2::{Digest, Sha256};
 
 pub trait Hasher {
@@ -7,6 +8,16 @@ pub trait Hasher {
 pub struct DefaultHasher;
 
 impl Hasher for DefaultHasher {
+    fn hash(&self, _input: &str) -> String {
+        "0xc0ff3".to_string()
+    }
+}
+
+#[cfg(feature = "sha256")]
+pub struct SHA256Hasher;
+
+#[cfg(feature = "sha256")]
+impl Hasher for SHA256Hasher {
     fn hash(&self, input: &str) -> String {
         let mut hasher = Sha256::new();
         hasher.update(input.as_bytes());
@@ -14,13 +25,13 @@ impl Hasher for DefaultHasher {
     }
 }
 
-#[cfg(test)]
+#[cfg(all(test, feature = "sha256"))]
 mod tests {
     use super::*;
 
     #[test]
-    fn test_default_hasher_with_known_input() {
-        let hasher = DefaultHasher;
+    fn test_sha256_hasher_with_known_input() {
+        let hasher = SHA256Hasher;
         let input = "hello";
         let expected_hash = "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824";
 
@@ -30,8 +41,8 @@ mod tests {
     }
 
     #[test]
-    fn test_default_hasher_empty_string() {
-        let hasher = DefaultHasher;
+    fn test_sha256_hasher_empty_string() {
+        let hasher = SHA256Hasher;
         let input = "";
         let expected_hash = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855";
 
diff --git a/src/merkle/mod.rs b/src/merkle/mod.rs
index b6da2f9..48f87bc 100644
--- a/src/merkle/mod.rs
+++ b/src/merkle/mod.rs
@@ -1,16 +1,16 @@
 mod merkletree;
 mod node;
 
-#[cfg(test)]
+#[cfg(all(test, feature = "sha256"))]
 mod tests {
-    use crate::hasher::DefaultHasher;
+    use crate::hasher::SHA256Hasher;
 
     use super::*;
 
     #[test]
     fn test_merkle_tree_hashing() {
         let data = vec!["a", "b", "c", "d"];
-        let tree = merkletree::MerkleTree::new(&DefaultHasher, data);
+        let tree = merkletree::MerkleTree::new(&SHA256Hasher, data);
 
         assert_eq!(tree.height(), 3);
 
@@ -23,7 +23,7 @@ mod tests {
     #[test]
     fn test_merkle_tree_single_leaf() {
         let data = vec!["hello"];
-        let tree = merkletree::MerkleTree::new(&DefaultHasher, data);
+        let tree = merkletree::MerkleTree::new(&SHA256Hasher, data);
 
         assert_eq!(tree.height(), 2);
         assert_eq!(tree.len(), 2);