From 7bc85dfa1956df4d60a5285c73c46dd4deb9798c Mon Sep 17 00:00:00 2001
From: Richard Ramos <info@richardramos.me>
Date: Thu, 27 Apr 2023 15:56:54 -0400
Subject: [PATCH] feat: expose `hash`, `poseidon_hash` and `delete_leaf`

---
 rln-wasm/Cargo.toml |  2 +-
 rln-wasm/src/lib.rs | 56 ++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/rln-wasm/Cargo.toml b/rln-wasm/Cargo.toml
index 6b61812..8d4e32e 100644
--- a/rln-wasm/Cargo.toml
+++ b/rln-wasm/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "rln-wasm"
-version = "0.0.7"
+version = "0.0.8"
 edition = "2021"
 license = "MIT or Apache2"
 
diff --git a/rln-wasm/src/lib.rs b/rln-wasm/src/lib.rs
index c765c13..9f79cca 100644
--- a/rln-wasm/src/lib.rs
+++ b/rln-wasm/src/lib.rs
@@ -7,7 +7,7 @@ use std::vec::Vec;
 
 use js_sys::{BigInt as JsBigInt, Object, Uint8Array};
 use num_bigint::BigInt;
-use rln::public::RLN;
+use rln::public::{hash, poseidon_hash, RLN};
 use wasm_bindgen::prelude::*;
 
 #[wasm_bindgen]
@@ -97,6 +97,40 @@ macro_rules! call_bool_method_with_error_msg {
     }
 }
 
+// Macro to execute a function with arbitrary amount of arguments,
+// First argument is the function to execute
+// Rest are all other arguments to the method
+macro_rules! fn_call_with_output_and_error_msg {
+    // this variant is needed for the case when
+    // there are zero other arguments
+    ($func:ident, $error_msg:expr) => {
+        {
+            let mut output_data: Vec<u8> = Vec::new();
+            if let Err(err) = $func(&mut output_data) {
+                std::mem::forget(output_data);
+                Err(format!("Msg: {:#?}, Error: {:#?}", $error_msg, err))
+            } else {
+                let result = Uint8Array::from(&output_data[..]);
+                std::mem::forget(output_data);
+                Ok(result)
+            }
+        }
+    };
+    ($func:ident, $error_msg:expr, $( $arg:expr ),* ) => {
+        {
+            let mut output_data: Vec<u8> = Vec::new();
+            if let Err(err) = $func($($arg.process()),*, &mut output_data) {
+                std::mem::forget(output_data);
+                Err(format!("Msg: {:#?}, Error: {:#?}", $error_msg, err))
+            } else {
+                let result = Uint8Array::from(&output_data[..]);
+                std::mem::forget(output_data);
+                Ok(result)
+            }
+        }
+    };
+}
+
 trait ProcessArg {
     type ReturnType;
     fn process(self) -> Self::ReturnType;
@@ -196,6 +230,12 @@ pub fn wasm_set_leaves_from(
     )
 }
 
+#[allow(clippy::not_unsafe_ptr_arg_deref)]
+#[wasm_bindgen(js_name = deleteLeaf)]
+pub fn wasm_delete_leaf(ctx: *mut RLNWrapper, index: usize) -> Result<(), String> {
+    call_with_error_msg!(ctx, delete_leaf, "could not delete leaf".to_string(), index)
+}
+
 #[allow(clippy::not_unsafe_ptr_arg_deref)]
 #[wasm_bindgen(js_name = initTreeWithLeaves)]
 pub fn wasm_init_tree_with_leaves(ctx: *mut RLNWrapper, input: Uint8Array) -> Result<(), String> {
@@ -333,3 +373,17 @@ pub fn wasm_verify_with_roots(
 pub fn wasm_get_root(ctx: *const RLNWrapper) -> Result<Uint8Array, String> {
     call_with_output_and_error_msg!(ctx, get_root, "could not obtain root")
 }
+
+#[wasm_bindgen(js_name = hash)]
+pub fn wasm_hash(input: Uint8Array) -> Result<Uint8Array, String> {
+    fn_call_with_output_and_error_msg!(hash, "could not generate hash", &input.to_vec()[..])
+}
+
+#[wasm_bindgen(js_name = poseidonHash)]
+pub fn wasm_poseidon_hash(input: Uint8Array) -> Result<Uint8Array, String> {
+    fn_call_with_output_and_error_msg!(
+        poseidon_hash,
+        "could not generate poseidon hash",
+        &input.to_vec()[..]
+    )
+}