use anyhow::Result;use indoc::formatdoc; use crate::connection::Connection; impl Connection {    // Run a set of commands within the context of a `SAVEPOINT name`. If the callback    // returns Err(_), the savepoint will be rolled back. Otherwise, the save    // point is released.    pub fn with_savepoint<R, F>(&self, name: impl AsRef<str>, f: F) -> Result<R>    where        F: FnOnce() -> Result<R>,    {        let name = name.as_ref();        self.exec(&format!("SAVEPOINT {name}"))?()?;        let result = f();        match result {            Ok(_) => {                self.exec(&format!("RELEASE {name}"))?()?;            }            Err(_) => {                self.exec(&formatdoc! {"                    ROLLBACK TO {name};                    RELEASE {name}"})?()?;            }        }        result    }     // Run a set of commands within the context of a `SAVEPOINT name`. If the callback    // returns Ok(None) or Err(_), the savepoint will be rolled back. Otherwise, the save    // point is released.    pub fn with_savepoint_rollback<R, F>(&self, name: impl AsRef<str>, f: F) -> Result<Option<R>>    where        F: FnOnce() -> Result<Option<R>>,    {        let name = name.as_ref();        self.exec(&format!("SAVEPOINT {name}"))?()?;        let result = f();        match result {            Ok(Some(_)) => {                self.exec(&format!("RELEASE {name}"))?()?;            }            Ok(None) | Err(_) => {                self.exec(&formatdoc! {"                    ROLLBACK TO {name};                    RELEASE {name}"})?()?;            }        }        result    }} #[cfg(test)]mod tests {    use crate::connection::Connection;    use anyhow::Result;    use indoc::indoc;     #[test]    fn test_nested_savepoints() -> Result<()> {        let connection = Connection::open_memory(Some("nested_savepoints"));         connection            .exec(indoc! {"            CREATE TABLE text (                text TEXT,                idx INTEGER            );"})            .unwrap()()        .unwrap();         let save1_text = "test save1";        let save2_text = "test save2";         connection.with_savepoint("first", || {            connection.exec_bound("INSERT INTO text(text, idx) VALUES (?, ?)")?((save1_text, 1))?;             assert!(connection                .with_savepoint("second", || -> Result<Option<()>, anyhow::Error> {                    connection.exec_bound("INSERT INTO text(text, idx) VALUES (?, ?)")?((                        save2_text, 2,                    ))?;                     assert_eq!(                        connection                            .select::<String>("SELECT text FROM text ORDER BY text.idx ASC")?(                        )?,                        vec![save1_text, save2_text],                    );                     anyhow::bail!("Failed second save point :(")                })                .err()                .is_some());             assert_eq!(                connection.select::<String>("SELECT text FROM text ORDER BY text.idx ASC")?()?,                vec![save1_text],            );             connection.with_savepoint_rollback::<(), _>("second", || {                connection.exec_bound("INSERT INTO text(text, idx) VALUES (?, ?)")?((                    save2_text, 2,                ))?;                 assert_eq!(                    connection.select::<String>("SELECT text FROM text ORDER BY text.idx ASC")?()?,                    vec![save1_text, save2_text],                );                 Ok(None)            })?;             assert_eq!(                connection.select::<String>("SELECT text FROM text ORDER BY text.idx ASC")?()?,                vec![save1_text],            );             connection.with_savepoint_rollback("second", || {                connection.exec_bound("INSERT INTO text(text, idx) VALUES (?, ?)")?((                    save2_text, 2,                ))?;                 assert_eq!(                    connection.select::<String>("SELECT text FROM text ORDER BY text.idx ASC")?()?,                    vec![save1_text, save2_text],                );                 Ok(Some(()))            })?;             assert_eq!(                connection.select::<String>("SELECT text FROM text ORDER BY text.idx ASC")?()?,                vec![save1_text, save2_text],            );             Ok(())        })?;         assert_eq!(            connection.select::<String>("SELECT text FROM text ORDER BY text.idx ASC")?()?,            vec![save1_text, save2_text],        );         Ok(())    }}