Add wasm bindings for Hash

sdk/program/src/wasm/hash.rs

@@ -0,0 +1,57 @@
+//! `Hash` Javascript interface
+#![cfg(target_arch = "wasm32")]
+#![allow(non_snake_case)]
+use {
+    crate::{hash::*, wasm::display_to_jsvalue},
+    js_sys::{Array, Uint8Array},
+    wasm_bindgen::{prelude::*, JsCast},
+};
+
+#[wasm_bindgen]
+impl Hash {
+    /// Create a new Hash object
+    ///
+    /// * `value` - optional hash as a base58 encoded string, `Uint8Array`, `[number]`
+    #[wasm_bindgen(constructor)]
+    pub fn constructor(value: JsValue) -> Result<Hash, JsValue> {
+        if let Some(base58_str) = value.as_string() {
+            base58_str.parse::<Hash>().map_err(display_to_jsvalue)
+        } else if let Some(uint8_array) = value.dyn_ref::<Uint8Array>() {
+            Ok(Hash::new(&uint8_array.to_vec()))
+        } else if let Some(array) = value.dyn_ref::<Array>() {
+            let mut bytes = vec![];
+            let iterator = js_sys::try_iter(&array.values())?.expect("array to be iterable");
+            for x in iterator {
+                let x = x?;
+
+                if let Some(n) = x.as_f64() {
+                    if n >= 0. && n <= 255. {
+                        bytes.push(n as u8);
+                        continue;
+                    }
+                }
+                return Err(format!("Invalid array argument: {:?}", x).into());
+            }
+            Ok(Hash::new(&bytes))
+        } else if value.is_undefined() {
+            Ok(Hash::default())
+        } else {
+            Err("Unsupported argument".into())
+        }
+    }
+
+    /// Return the base58 string representation of the hash
+    pub fn toString(&self) -> String {
+        self.to_string()
+    }
+
+    /// Checks if two `Hash`s are equal
+    pub fn equals(&self, other: &Hash) -> bool {
+        self == other
+    }
+
+    /// Return the `Uint8Array` representation of the hash
+    pub fn toBytes(&self) -> Box<[u8]> {
+        self.0.clone().into()
+    }
+}

sdk/program/src/wasm/mod.rs

@@ -2,13 +2,19 @@
 #![cfg(target_arch = "wasm32")]
 use wasm_bindgen::prelude::*;
 
+pub mod hash;
 pub mod pubkey;
 
 /// Initialize Javascript logging and panic handler
 #[wasm_bindgen]
 pub fn init() {
-    std::panic::set_hook(Box::new(console_error_panic_hook::hook));
-    console_log::init_with_level(log::Level::Info).unwrap();
+    use std::sync::Once;
+    static INIT: Once = Once::new();
+
+    INIT.call_once(|| {
+        std::panic::set_hook(Box::new(console_error_panic_hook::hook));
+        console_log::init_with_level(log::Level::Info).unwrap();
+    });
 }
 
 pub fn display_to_jsvalue<T: std::fmt::Display>(display: T) -> JsValue {