Improve error handling and add rand dependency

This makes panics more visible in the console and fixes a weird bug
where the rand package was throwing an error.

crates/lox-wasm/Cargo.toml

@@ -13,3 +13,7 @@ crate-type = ["cdylib"]
 lox = { git = "https://git-crysp.uwaterloo.ca/iang/lox.git" }
 wasm-bindgen = "0.2"
 serde_json = "1.0.87"
+
+console_error_panic_hook = "0.1.7"
+
+rand = { version = "0.7", features = ["wasm-bindgen"] }

crates/lox-wasm/src/lib.rs

@@ -2,6 +2,8 @@ use wasm_bindgen::prelude::*;
 use lox::OPENINV_LENGTH;
 use lox::proto::open_invite;
 use serde_json;
+use std::array::TryFromSliceError;
+use std::panic;
 
 #[wasm_bindgen]
 extern {
@@ -9,15 +11,26 @@ extern {
     pub fn log(s: &str);
 }
 
+#[wasm_bindgen]
+pub fn set_panic_hook() {
+    panic::set_hook(Box::new(console_error_panic_hook::hook));
+}
+
 #[wasm_bindgen]
 pub fn open_invite(invite: &[u8]) {
-
+    log(&format!("Using invite: {:?}", invite));
-    let (request, _state) = open_invite::request(&validate_invite(invite));
+    match validate(invite) {
+        Ok(token) => {
+            let (request, _state) = open_invite::request(&token);
             let serialized_request = serde_json::to_string(&request).unwrap();
-    log(&format!("request: {}", serialized_request));
+            log(&format!("Formatted open invite request: {}", serialized_request));
+        },
+        Err(e) => {
+            log(&format!("{:?}", e));
+        },
+    }
 }
 
-
+fn validate(invite: &[u8]) -> Result<[u8; OPENINV_LENGTH], TryFromSliceError> {
-fn validate_invite(invite: &[u8]) -> [u8; OPENINV_LENGTH] {
+    invite.try_into()
-    invite.try_into().expect("slice with incorrect length")
 }