add test for simple proof

ssz-rs/src/merkleization/proofs.rs

@@ -68,8 +68,8 @@ pub fn is_valid_merkle_branch_for_generalized_index<T: AsRef<[u8]>>(
     generalized_index: GeneralizedIndex,
     root: Node,
 ) -> Result<(), Error> {
-    let index = log_2(generalized_index).ok_or(Error::InvalidGeneralizedIndex)? as usize;
-    let depth = get_subtree_index(generalized_index)?;
+    let depth = log_2(generalized_index).ok_or(Error::InvalidGeneralizedIndex)? as usize;
+    let index = get_subtree_index(generalized_index)?;
     is_valid_merkle_branch(leaf, branch, depth, index, root)
 }
 
@@ -121,7 +121,7 @@ mod tests {
     }
 
     #[test]
-    fn test_basic_proof() {
+    fn test_is_valid_merkle_branch() {
         let leaf = decode_node_from_hex(
             "94159da973dfa9e40ed02535ee57023ba2d06bad1017e451055470967eb71cd5",
         );
@@ -142,6 +142,29 @@ mod tests {
         assert!(is_valid_merkle_branch(leaf, &branch, depth, index, root).is_ok());
     }
 
+    #[test]
+    fn test_simple_proof() {
+        let leaf = decode_node_from_hex(
+            "94159da973dfa9e40ed02535ee57023ba2d06bad1017e451055470967eb71cd5",
+        );
+        let branch = [
+            "8f594dbb4f4219ad4967f86b9cccdb26e37e44995a291582a431eef36ecba45c",
+            "f8c2ed25e9c31399d4149dcaa48c51f394043a6a1297e65780a5979e3d7bb77c",
+            "382ba9638ce263e802593b387538faefbaed106e9f51ce793d405f161b105ee6",
+        ]
+        .into_iter()
+        .map(decode_node_from_hex)
+        .collect::<Vec<_>>();
+        let depth = 3;
+        let index = 2;
+        let proof = Proof { leaf, branch, index: 2usize.pow(depth) + index };
+        let root = decode_node_from_hex(
+            "27097c728aade54ff1376d5954681f6d45c282a81596ef19183148441b754abb",
+        );
+        let result = proof.verify(root);
+        assert!(result.is_ok());
+    }
+
     #[test]
     fn test_proving_primitives() {
         let mut data = 8u8;