fix(anvil): clear db on reset (#3505)

anvil/src/eth/backend/db.rs

@@ -41,6 +41,9 @@ pub trait MaybeHashDatabase: DatabaseRef<Error = DatabaseError> {
     /// Clear the state and move it into a new `StateSnapshot`
     fn clear_into_snapshot(&mut self) -> StateSnapshot;
 
+    /// Clears the entire database
+    fn clear(&mut self);
+
     /// Reverses `clear_into_snapshot` by initializing the db's state with the snapshot
     fn init_from_snapshot(&mut self, snapshot: StateSnapshot);
 }
@@ -57,9 +60,11 @@ where
     }
 
     fn clear_into_snapshot(&mut self) -> StateSnapshot {
-        unimplemented!()
+        unreachable!("never called for DatabaseRef")
     }
 
+    fn clear(&mut self) {}
+
     fn init_from_snapshot(&mut self, _snapshot: StateSnapshot) {}
 }
 
@@ -192,6 +197,10 @@ impl<T: DatabaseRef<Error = DatabaseError>> MaybeHashDatabase for CacheDB<T> {
         StateSnapshot { accounts, storage: account_storage, block_hashes }
     }
 
+    fn clear(&mut self) {
+        self.clear_into_snapshot();
+    }
+
     fn init_from_snapshot(&mut self, snapshot: StateSnapshot) {
         let StateSnapshot { accounts, mut storage, block_hashes } = snapshot;
 
@@ -255,6 +264,10 @@ impl MaybeHashDatabase for StateDb {
         self.0.clear_into_snapshot()
     }
 
+    fn clear(&mut self) {
+        self.0.clear()
+    }
+
     fn init_from_snapshot(&mut self, snapshot: StateSnapshot) {
         self.0.init_from_snapshot(snapshot)
     }

anvil/src/eth/backend/mem/fork_db.rs

@@ -57,6 +57,11 @@ impl MaybeHashDatabase for ForkedDatabase {
         StateSnapshot { accounts, storage, block_hashes }
     }
 
+    fn clear(&mut self) {
+        self.flush_cache();
+        self.clear_into_snapshot();
+    }
+
     fn init_from_snapshot(&mut self, snapshot: StateSnapshot) {
         let db = self.inner().db();
         let StateSnapshot { accounts, storage, block_hashes } = snapshot;
@@ -70,6 +75,11 @@ impl MaybeHashDatabase for ForkDbSnapshot {
         std::mem::take(&mut self.snapshot)
     }
 
+    fn clear(&mut self) {
+        std::mem::take(&mut self.snapshot);
+        self.local.clear()
+    }
+
     fn init_from_snapshot(&mut self, snapshot: StateSnapshot) {
         self.snapshot = snapshot;
     }

anvil/src/eth/backend/mem/in_memory_db.rs

@@ -132,6 +132,10 @@ impl MaybeHashDatabase for MemDb {
         self.inner.clear_into_snapshot()
     }
 
+    fn clear(&mut self) {
+        self.inner.clear();
+    }
+
     fn init_from_snapshot(&mut self, snapshot: StateSnapshot) {
         self.inner.init_from_snapshot(snapshot)
     }

anvil/src/eth/backend/mem/mod.rs

@@ -327,6 +327,10 @@ impl Backend {
             // insert back all genesis accounts, by reusing cached `AccountInfo`s we don't need to
             // fetch the data via RPC again
             let mut db = self.db.write().await;
+
+            // clear database
+            db.clear();
+
             let fork_genesis_infos = self.genesis.fork_genesis_account_infos.lock();
             for (address, info) in
                 self.genesis.accounts.iter().copied().zip(fork_genesis_infos.iter().cloned())