From 64ea0a2059f678541dce32a3df909f0fee6b05d1 Mon Sep 17 00:00:00 2001
From: Tarek Mohamed Abdalla <tarekkma@gmail.com>
Date: Thu, 30 Mar 2023 00:25:53 +0200
Subject: [PATCH 1/2] review

---
 pallets/energy/src/tests.rs | 53 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 52 insertions(+), 1 deletion(-)

diff --git a/pallets/energy/src/tests.rs b/pallets/energy/src/tests.rs
index 1b637252..47adb5a8 100644
--- a/pallets/energy/src/tests.rs
+++ b/pallets/energy/src/tests.rs
@@ -572,7 +572,58 @@ fn existential_deposit_and_providers() {
         });
 }
 
-// TODO Add a test for DustLost event
+
+///// tests for dust lost event
+
+#[test]
+fn dust_lost_should_not_be_emitted_when_ed_is_zero() {
+    ExtBuilder::default()
+        .energy_existential_deposit(0)
+        .build()
+        .execute_with(|| {
+            let account = 1;
+            set_energy_balance(account, 100);
+
+            assert_ok!(charge_transaction(&account, 100, 100, 0, || {}));
+
+            assert!(!System::events()
+                .iter()
+                .any(|record| matches!(record.event, RuntimeEvent::Energy(EnergyEvent::DustLost { .. }))));
+        });
+}
+
+#[test]
+fn dust_lost_should_not_be_emitted_when_energy_still_above_ed() {
+    ExtBuilder::default()
+        .energy_existential_deposit(10)
+        .build()
+        .execute_with(|| {
+            let account = 1;
+            set_energy_balance(account, 100);
+
+            assert_ok!(charge_transaction(&account, 90, 90, 0, || {}));
+
+            assert!(!System::events()
+                .iter()
+                .any(|record| matches!(record.event, RuntimeEvent::Energy(EnergyEvent::DustLost { .. }))));
+        });
+}
+
+#[test]
+fn dust_lost_should_be_emitted_when_energy_still_below_ed() {
+    ExtBuilder::default()
+        .energy_existential_deposit(10)
+        .build()
+        .execute_with(|| {
+            let account = 1;
+            set_energy_balance(account, 100);
+
+            assert_ok!(charge_transaction(&account, 98, 98, 0, || {}));
+
+            System::assert_has_event(EnergyEvent::DustLost { account, amount: 2 }.into());
+        });
+}
+
 
 ///// test native_token_to_energy
 

From 220f1b4fcd50e67a30bad589f59cb8c70cc7cb26 Mon Sep 17 00:00:00 2001
From: Vlad Proshchavaiev <32250097+F3Joule@users.noreply.github.com>
Date: Fri, 5 Jan 2024 16:23:10 +0200
Subject: [PATCH 2/2] Apply suggestions from code review

---
 pallets/energy/src/tests.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pallets/energy/src/tests.rs b/pallets/energy/src/tests.rs
index 47adb5a8..34062636 100644
--- a/pallets/energy/src/tests.rs
+++ b/pallets/energy/src/tests.rs
@@ -573,7 +573,7 @@ fn existential_deposit_and_providers() {
 }
 
 
-///// tests for dust lost event
+// Tests for DustLost event
 
 #[test]
 fn dust_lost_should_not_be_emitted_when_ed_is_zero() {