diff --git a/service_impl/src/test/error_test.rs b/service_impl/src/test/error_test.rs
new file mode 100644
index 0000000..5eb18fb
--- /dev/null
+++ b/service_impl/src/test/error_test.rs
@@ -0,0 +1,108 @@
+use service::ValidationFailureItem;
+use uuid::Uuid;
+
+pub fn test_forbidden<T>(result: &Result<T, service::ServiceError>) {
+    if let Err(service::ServiceError::Forbidden) = result {
+        // All good
+    } else {
+        panic!("Expected forbidden error");
+    }
+}
+
+pub fn test_not_found<T>(result: &Result<T, service::ServiceError>, target_id: &Uuid) {
+    if let Err(service::ServiceError::EntityNotFound(id)) = result {
+        assert_eq!(
+            id, target_id,
+            "Expected entity {} not found but got {}",
+            target_id, id
+        );
+    } else {
+        panic!("Expected entity {} not found error", target_id);
+    }
+}
+
+pub fn test_zero_id_error<T>(result: &Result<T, service::ServiceError>) {
+    if let Err(service::ServiceError::IdSetOnCreate) = result {
+    } else {
+        panic!("Expected id set on create error");
+    }
+}
+
+pub fn test_zero_version_error<T>(result: &Result<T, service::ServiceError>) {
+    if let Err(service::ServiceError::VersionSetOnCreate) = result {
+    } else {
+        panic!("Expected version set on create error");
+    }
+}
+
+pub fn test_overlapping_time_range_error<T>(result: &Result<T, service::ServiceError>) {
+    if let Err(service::ServiceError::OverlappingTimeRange) = result {
+    } else {
+        panic!("Expected overlapping time range error");
+    }
+}
+
+pub fn test_time_order_wrong<T>(result: &Result<T, service::ServiceError>) {
+    if let Err(service::ServiceError::TimeOrderWrong(_from, _to)) = result {
+    } else {
+        panic!("Expected time order failure");
+    }
+}
+
+pub fn test_date_order_wrong<T>(result: &Result<T, service::ServiceError>) {
+    if let Err(service::ServiceError::DateOrderWrong(_from, _to)) = result {
+    } else {
+        panic!("Expected date order failure");
+    }
+}
+
+pub fn test_conflicts<T>(
+    result: &Result<T, service::ServiceError>,
+    target_id: &Uuid,
+    expected_version: &Uuid,
+    actual_version: &Uuid,
+) {
+    if let Err(service::ServiceError::EntityConflicts(
+        err_id,
+        err_expected_version,
+        err_actual_version,
+    )) = result
+    {
+        assert_eq!(
+            err_id, target_id,
+            "Expected entity {} conflicts but got {}",
+            target_id, err_id
+        );
+
+        assert_eq!(
+            expected_version, err_expected_version,
+            "Expected expected version {} but got {}",
+            expected_version, err_expected_version
+        );
+        assert_eq!(
+            actual_version, err_actual_version,
+            "Expected actual version {} but got {}",
+            actual_version, err_actual_version
+        );
+    } else {
+        panic!("Expected entity {} conflicts error", target_id);
+    }
+}
+
+pub fn test_validation_error(
+    result: &Result<(), service::ServiceError>,
+    validation_failure: &ValidationFailureItem,
+    fail_count: usize,
+) {
+    if let Err(service::ServiceError::ValidationError(validation_failure_items)) = result {
+        if !validation_failure_items.contains(validation_failure) {
+            panic!(
+                "Validation failure not found: {:?} in {:?}",
+                validation_failure, validation_failure_items
+            );
+        }
+        assert_eq!(fail_count, validation_failure_items.len());
+    } else {
+        panic!("Expected validation error");
+    }
+}
diff --git a/service_impl/src/test/mod.rs b/service_impl/src/test/mod.rs
index d5479d7..47715f1 100644
--- a/service_impl/src/test/mod.rs
+++ b/service_impl/src/test/mod.rs
@@ -1,4 +1,6 @@
 #[cfg(test)]
+pub mod error_test;
+#[cfg(test)]
 mod permission_test;
 #[cfg(test)]
 pub mod slot;
diff --git a/service_impl/src/test/permission_test.rs b/service_impl/src/test/permission_test.rs
index c730ae5..1af02dc 100644
--- a/service_impl/src/test/permission_test.rs
+++ b/service_impl/src/test/permission_test.rs
@@ -1,3 +1,4 @@
+use crate::test::error_test::*;
 use crate::*;
 use mockall::predicate::eq;
 use service::PermissionService;
@@ -20,14 +21,6 @@ fn generate_dependencies_mocks_permission(
     (permission_dao, user_service)
 }
 
-pub fn test_forbidden<T>(result: &Result<T, service::ServiceError>) {
-    if let Err(service::ServiceError::Forbidden) = result {
-        // All good
-    } else {
-        panic!("Expected forbidden error");
-    }
-}
-
 #[tokio::test]
 async fn test_check_permission() {
     let (permission_dao, user_service) = generate_dependencies_mocks_permission(true, "hello");
diff --git a/service_impl/src/test/slot.rs b/service_impl/src/test/slot.rs
index f37216a..8621303 100644
--- a/service_impl/src/test/slot.rs
+++ b/service_impl/src/test/slot.rs
@@ -1,7 +1,7 @@
 use std::sync::Arc;
 
 use crate::slot::*;
-use crate::test::permission_test::test_forbidden;
+use crate::test::error_test::*;
 use dao::slot::{MockSlotDao, SlotEntity};
 use mockall::predicate::eq;
 use service::{
@@ -47,104 +47,6 @@ pub fn generate_default_slot_entity() -> SlotEntity {
     }
 }
 
-pub fn test_not_found<T>(result: &Result<T, service::ServiceError>, target_id: &Uuid) {
-    if let Err(service::ServiceError::EntityNotFound(id)) = result {
-        assert_eq!(
-            id, target_id,
-            "Expected entity {} not found but got {}",
-            target_id, id
-        );
-    } else {
-        panic!("Expected entity {} not found error", target_id);
-    }
-}
-
-pub fn test_zero_id_error<T>(result: &Result<T, service::ServiceError>) {
-    if let Err(service::ServiceError::IdSetOnCreate) = result {
-    } else {
-        panic!("Expected id set on create error");
-    }
-}
-
-pub fn test_zero_version_error<T>(result: &Result<T, service::ServiceError>) {
-    if let Err(service::ServiceError::VersionSetOnCreate) = result {
-    } else {
-        panic!("Expected version set on create error");
-    }
-}
-
-pub fn test_overlapping_time_range_error<T>(result: &Result<T, service::ServiceError>) {
-    if let Err(service::ServiceError::OverlappingTimeRange) = result {
-    } else {
-        panic!("Expected overlapping time range error");
-    }
-}
-
-pub fn test_time_order_wrong<T>(result: &Result<T, service::ServiceError>) {
-    if let Err(service::ServiceError::TimeOrderWrong(_from, _to)) = result {
-    } else {
-        panic!("Expected time order failure");
-    }
-}
-
-pub fn test_date_order_wrong<T>(result: &Result<T, service::ServiceError>) {
-    if let Err(service::ServiceError::DateOrderWrong(_from, _to)) = result {
-    } else {
-        panic!("Expected date order failure");
-    }
-}
-
-pub fn test_conflicts<T>(
-    result: &Result<T, service::ServiceError>,
-    target_id: &Uuid,
-    expected_version: &Uuid,
-    actual_version: &Uuid,
-) {
-    if let Err(service::ServiceError::EntityConflicts(
-        err_id,
-        err_expected_version,
-        err_actual_version,
-    )) = result
-    {
-        assert_eq!(
-            err_id, target_id,
-            "Expected entity {} conflicts but got {}",
-            target_id, err_id
-        );
-
-        assert_eq!(
-            expected_version, err_expected_version,
-            "Expected expected version {} but got {}",
-            expected_version, err_expected_version
-        );
-        assert_eq!(
-            actual_version, err_actual_version,
-            "Expected actual version {} but got {}",
-            actual_version, err_actual_version
-        );
-    } else {
-        panic!("Expected entity {} conflicts error", target_id);
-    }
-}
-
-pub fn test_validation_error(
-    result: &Result<(), service::ServiceError>,
-    validation_failure: &ValidationFailureItem,
-    fail_count: usize,
-) {
-    if let Err(service::ServiceError::ValidationError(validation_failure_items)) = result {
-        if !validation_failure_items.contains(validation_failure) {
-            panic!(
-                "Validation failure not found: {:?} in {:?}",
-                validation_failure, validation_failure_items
-            );
-        }
-        assert_eq!(fail_count, validation_failure_items.len());
-    } else {
-        panic!("Expected validation error");
-    }
-}
-
 pub struct SlotServiceDependencies {
     pub slot_dao: MockSlotDao,
     pub permission_service: MockPermissionService,