diff --git a/src/handlers/customers.rs b/src/handlers/customers.rs
index b348061..9868c22 100644
--- a/src/handlers/customers.rs
+++ b/src/handlers/customers.rs
@@ -56,61 +56,86 @@ pub fn destroy(id: i32, conn: DbConn) -> NoContentResponse {
 #[cfg(test)]
 mod tests {
     use rocket::http::{Accept, ContentType, Status};
-    use rocket::local::Client;
     use serde_json::{self, json};
 
     use super::*;
-    use crate::rocket;
+
+    macro_rules! run_test {
+        (|$client:ident, $conn:ident| $block:expr) => {{
+            let rocket = crate::rocket();
+            let db = crate::DbConn::get_one(&rocket);
+            let $conn = db.expect("Failed to get database connection for testing");
+            let $client =
+                rocket::local::Client::new(rocket).expect("Failed to set up Rocket client");
+
+            $block
+        }};
+    }
 
     #[test]
     fn index() {
-        let client = Client::new(rocket()).unwrap();
+        run_test!(|client, _conn| {
+            let mut res = client.get("/customers").header(Accept::JSON).dispatch();
+            assert_eq!(res.status(), Status::Ok);
 
-        let mut res = client.get("/customers").header(Accept::JSON).dispatch();
-        assert_eq!(res.status(), Status::Ok);
-
-        let body = res.body_string().unwrap();
-        let customers = serde_json::from_str::<Vec<Customer>>(body.as_str()).unwrap();
-        assert_eq!(customers, vec![]);
-        // FIXME: Actually have something in de the index!
+            let body = res.body_string().unwrap();
+            let customers = serde_json::from_str::<Vec<Customer>>(body.as_str()).unwrap();
+            assert_eq!(customers.len(), 2);
+        });
     }
 
     #[test]
     fn create() {
-        let client = Client::new(rocket()).unwrap();
+        run_test!(|client, conn| {
+            let new_customer_json = json!({
+                "name": "Test Company"
+            });
+            let res = client
+                .post("/customers")
+                .header(ContentType::JSON)
+                .header(Accept::JSON)
+                .body(new_customer_json.to_string())
+                .dispatch();
+            assert_eq!(res.status(), Status::UnprocessableEntity);
 
-        let new_customer_json = json!({
-            "name": "Test Company"
-        });
-        let res = client
-            .post("/customers")
-            .header(ContentType::JSON)
-            .header(Accept::JSON)
-            .body(new_customer_json.to_string())
-            .dispatch();
-        assert_eq!(res.status(), Status::UnprocessableEntity);
+            let customers: Vec<Customer> = all!(Customer, *conn).expect("Customers");
+            let new_customer_json = json!({
+                "address_city": "Some City",
+                "address_postal_code": "123456",
+                "address_street": "Somestreet",
+                "email": "info@testcompany.tld",
+                "financial_contact": "Financial Office",
+                "hourly_rate": 100.0,
+                "name": "New Test Company",
+                "phone": "0123456789",
+                "short_name": "Test Co.",
+                "time_specification": true,
+            });
+            let mut res = client
+                .post("/customers")
+                .header(ContentType::JSON)
+                .header(Accept::JSON)
+                .body(new_customer_json.to_string())
+                .dispatch();
+            assert_eq!(res.status(), Status::Created);
+            let body = res.body_string().unwrap();
+            let customer = serde_json::from_str::<Customer>(body.as_str()).unwrap();
+            assert_eq!(customer.name, "New Test Company");
 
-        let new_customer_json = json!({
-          "address_city": "Some City",
-          "address_postal_code": "123456",
-          "address_street": "Somestreet",
-          "email": "info@testcompany.tld",
-          "financial_contact": "Financial Office",
-          "hourly_rate": 100.0,
-          "name": "Test Company",
-          "phone": "0123456789",
-          "short_name": "Test Co.",
-          "time_specification": true
-        });
-        let mut res = client
-            .post("/customers")
-            .header(ContentType::JSON)
-            .header(Accept::JSON)
-            .body(new_customer_json.to_string())
-            .dispatch();
-        assert_eq!(res.status(), Status::Created);
-        let body = res.body_string().unwrap();
-        let new_customer = serde_json::from_str::<Customer>(body.as_str()).unwrap();
-        assert_eq!(new_customer.name, "Test Company");
+            let customers_after: Vec<Customer> = all!(Customer, *conn).expect("Customers");
+            assert_eq!(customers_after.len(), customers.len() + 1);
+        })
     }
+
+    #[test]
+    fn new() {}
+
+    #[test]
+    fn show() {}
+
+    #[test]
+    fn update() {}
+
+    #[test]
+    fn destroy() {}
 }
diff --git a/src/rest_helpers.rs b/src/rest_helpers.rs
index 1a37fc0..4300fce 100644
--- a/src/rest_helpers.rs
+++ b/src/rest_helpers.rs
@@ -116,9 +116,11 @@ macro_rules! get {
 macro_rules! create {
     ($model_name:ident, $object:expr, $conn:expr) => {{
         use diesel::associations::HasTable;
+        use diesel::{ExpressionMethods, QueryDsl, RunQueryDsl, Table};
+
         let table = $crate::models::$model_name::table();
         let primary_key = table.primary_key();
-        $conn.transaction::<_, diesel::result::Error, _>(|| {
+        $conn.transaction::<$model_name, diesel::result::Error, _>(|| {
             diesel::insert_into(table).values($object).execute(&$conn)?;
             table.order(primary_key.desc()).first(&$conn)
         })
@@ -128,6 +130,7 @@ macro_rules! create {
 macro_rules! update {
     ($model_name:ident, $primary_key:expr, $object:expr, $conn:expr) => {{
         use diesel::associations::HasTable;
+
         let table = $crate::models::$model_name::table();
         $conn.transaction::<_, diesel::result::Error, _>(|| {
             diesel::update(table.find($primary_key))
@@ -141,6 +144,7 @@ macro_rules! update {
 macro_rules! destroy {
     ($model_name:ident, $primary_key:expr, $conn:expr) => {{
         use diesel::associations::HasTable;
+
         let table = $crate::models::$model_name::table();
         let result: Result<$model_name, _> = get!($model_name, $primary_key, $conn);
         match result {