test(semaphore): Import basic end to end test

semaphore/src/lib.rs

@@ -1,8 +1,40 @@
 #[cfg(test)]
 mod tests {
+    use semaphore::{
+        hash_to_field, identity::Identity, poseidon_tree::PoseidonTree, protocol::*, Field,
+    };
+
     #[test]
-    fn it_works() {
-        let result = 2 + 2;
-        assert_eq!(result, 4);
+    fn test_semaphore() {
+        // generate identity
+        let id = Identity::from_seed(b"secret");
+
+        // generate merkle tree
+        let leaf = Field::from(0);
+        let mut tree = PoseidonTree::new(21, leaf);
+        tree.set(0, id.commitment());
+
+        let merkle_proof = tree.proof(0).expect("proof should exist");
+        let root = tree.root().into();
+
+        // change signal and external_nullifier here
+        let signal_hash = hash_to_field(b"xxx");
+        let external_nullifier_hash = hash_to_field(b"appId");
+
+        let nullifier_hash = generate_nullifier_hash(&id, external_nullifier_hash);
+
+        let proof =
+            generate_proof(&id, &merkle_proof, external_nullifier_hash, signal_hash).unwrap();
+
+        let success = verify_proof(
+            root,
+            nullifier_hash,
+            signal_hash,
+            external_nullifier_hash,
+            &proof,
+        )
+        .unwrap();
+
+        assert!(success);
     }
 }