chore: fix some docs (#6701)

crates/evm/core/src/backend/in_memory_db.rs

@@ -84,9 +84,12 @@ impl DatabaseCommit for MemDb {
 /// `DbAccount`, this will be set to `AccountState::NotExisting` if the account does not exist yet.
 /// This is because there's a distinction between "non-existing" and "empty",
 /// see <https://github.com/bluealloy/revm/blob/8f4348dc93022cffb3730d9db5d3ab1aad77676a/crates/revm/src/db/in_memory_db.rs#L81-L83>.
-/// If an account is `NotExisting`, `Database(Ref)::basic` will always return `None` for the
-/// requested `AccountInfo`. To prevent this, we ensure that a missing account is never marked as
-/// `NotExisting` by always returning `Some` with this type.
+/// If an account is `NotExisting`, `Database::basic_ref` will always return `None` for the
+/// requested `AccountInfo`.
+///
+/// To prevent this, we ensure that a missing account is never marked as `NotExisting` by always
+/// returning `Some` with this type, which will then insert a default [`AccountInfo`] instead
+/// of one marked as `AccountState::NotExisting`.
 #[derive(Clone, Debug, Default)]
 pub struct EmptyDBWrapper(EmptyDB);
 
@@ -143,6 +146,7 @@ mod tests {
         let mut db = CacheDB::new(EmptyDB::default());
         let address = Address::random();
 
+        // We use `basic_ref` here to ensure that the account is not marked as `NotExisting`.
         let info = DatabaseRef::basic_ref(&db, address).unwrap();
         assert!(info.is_none());
         let mut info = info.unwrap_or_default();
@@ -165,6 +169,8 @@ mod tests {
         ));
 
         let info = Database::basic(&mut db, address).unwrap();
+        // We know info exists, as MemDb always returns `Some(AccountInfo)` due to the
+        // `EmptyDbWrapper`.
         assert!(info.is_some());
         let mut info = info.unwrap();
         info.balance = U256::from(500u64);

crates/evm/core/src/backend/mod.rs

@@ -69,8 +69,8 @@ pub trait DatabaseExt: Database<Error = DatabaseError> {
     /// Creates a new snapshot at the current point of execution.
     ///
     /// A snapshot is associated with a new unique id that's created for the snapshot.
-    /// Snapshots can be reverted: [DatabaseExt::revert], however a snapshot can only be reverted
-    /// once. After a successful revert, the same snapshot id cannot be used again.
+    /// Snapshots can be reverted: [DatabaseExt::revert], however, depending on the
+    /// [RevertSnapshotAction], it will keep the snapshot alive or delete it.
     fn snapshot(&mut self, journaled_state: &JournaledState, env: &Env) -> U256;
 
     /// Reverts the snapshot if it exists
@@ -204,21 +204,21 @@ pub trait DatabaseExt: Database<Error = DatabaseError> {
     /// Returns the Fork url that's currently used in the database, if fork mode is on
     fn active_fork_url(&self) -> Option<String>;
 
-    /// Whether the database is currently in forked
+    /// Whether the database is currently in forked mode.
     fn is_forked_mode(&self) -> bool {
         self.active_fork_id().is_some()
     }
 
-    /// Ensures that an appropriate fork exits
+    /// Ensures that an appropriate fork exists
     ///
-    /// If `id` contains a requested `Fork` this will ensure it exits.
+    /// If `id` contains a requested `Fork` this will ensure it exists.
     /// Otherwise, this returns the currently active fork.
     ///
     /// # Errors
     ///
     /// Returns an error if the given `id` does not match any forks
     ///
-    /// Returns an error if no fork exits
+    /// Returns an error if no fork exists
     fn ensure_fork(&self, id: Option<LocalForkId>) -> eyre::Result<LocalForkId>;
 
     /// Ensures that a corresponding `ForkId` exists for the given local `id`

crates/evm/evm/src/executors/mod.rs

@@ -2,7 +2,7 @@
 //!
 //! Used for running tests, scripts, and interacting with the inner backend which holds the state.
 
-// TODO: The individual executors in this module should be moved into the respective craits, and the
+// TODO: The individual executors in this module should be moved into the respective crates, and the
 // `Executor` struct should be accessed using a trait defined in `foundry-evm-core` instead of
 // the concrete `Executor` type.