make to_i64 more resilient and clearer error message on client setup

backend/windmill-api/src/oauth2.rs

@@ -415,7 +415,7 @@ async fn connect_slack(cookies: Cookies) -> error::Result<Redirect> {
     let mut client = OAUTH_CLIENTS
         .slack
         .as_ref()
-        .ok_or_else(|| error::Error::BadRequest("slack client not setup".to_string()))?
+        .ok_or_else(|| error::Error::BadRequest("slack client not setup. See: https://docs.windmill.dev/docs/misc/setup_oauth#slack".to_string()))?
         .to_owned();
     let state = State::new_random();
 
@@ -616,7 +616,7 @@ async fn connect_slack_callback(
     let client = OAUTH_CLIENTS
         .slack
         .as_ref()
-        .ok_or_else(|| error::Error::BadRequest("slack client not setup".to_string()))?
+        .ok_or_else(|| error::Error::BadRequest("slack client not setup. See: https://docs.windmill.dev/docs/misc/setup_oauth#slack".to_string()))?
         .to_owned();
     let token =
         exchange_code::<SlackTokenResponse>(callback, &cookies, client, &HTTP_CLIENT, None).await?;

backend/windmill-common/src/scripts.rs

@@ -209,6 +209,11 @@ pub struct ListScriptQuery {
 
 pub fn to_i64(s: &str) -> crate::error::Result<i64> {
     let v = hex::decode(s)?;
+    if v.len() < 8 {
+        return Err(crate::error::Error::BadRequest(format!(
+            "hex string did not decode to an u64: {s}",
+        )));
+    }
     let nb: u64 = u64::from_be_bytes(
         v[0..8]
             .try_into()