feat: function to check if a job id exists

src/spawn.rs

@@ -171,3 +171,15 @@ pub async fn clear_all<'b, E: sqlx::Executor<'b, Database = Postgres>>(
         .await?;
     Ok(())
 }
+
+/// Check if a job with that ID exists
+pub async fn exists<'b, E: sqlx::Executor<'b, Database = Postgres>>(
+    executor: E,
+    id: Uuid,
+) -> Result<bool, sqlx::Error> {
+    let exists = sqlx::query_scalar("SELECT EXISTS(SELECT id FROM mq_msgs WHERE id = $1)")
+        .bind(id)
+        .fetch_one(executor)
+        .await?;
+    Ok(exists)
+}