src/cli/add.rs

@@ -12,6 +12,7 @@ pub fn execute(repo: impl Repository, args: Args) {
     let res = repo.insert_task(repo::InsertTaskData {
         name: args.name,
         link: args.link,
+        index: None,
     });
 
     match res {

src/cli/edit.rs

@@ -1,7 +1,4 @@
-use std::io::Write;
-
 use crate::repo::{self, Repository};
-use crate::CurrentTaskInfo;
 
 #[derive(clap::Args)]
 pub struct Args {
@@ -16,23 +13,22 @@ pub struct Args {
     idx: usize,
 }
 
-pub struct Request {
+pub fn execute(repo: impl Repository, args: Args) {
-    pub args: Args,
+    match repo.get_current_task_opt() {
-    pub current_task_info: Option<CurrentTaskInfo>,
+        Ok(Some(_)) => {
-}
+            return eprintln!("You can edit task only when you don't have an active task, yet")
-
+        }
-pub fn execute(repo: impl Repository, mut req: Request) {
+        Err(err) => {
-    if req.current_task_info.is_some() {
+            return eprintln!("Cannot read current task: {}", err);
-        panic!("You can edit task only when you don't have an active task, yet");
+        }
+        _ => {}
     }
 
-    let args = req.args;
-
     let res = repo.update_task(
         args.idx,
         repo::UpdateTaskData {
             name: args.name,
-            link: args.no_link.then(|| None).or(args.link.map(Some)),
+            link: args.no_link.then(|| None).or_else(|| args.link.map(Some)),
         },
     );
     match res {

src/cli/finish.rs

@@ -1,41 +1,17 @@
-use crate::{CurrentTaskInfo, Task};
+use crate::repo::{self, Repository};
-use std::io::Write;
-use std::path::PathBuf;
 
-pub struct Request {
+pub fn execute(repo: impl Repository) {
-    pub current_task_info: Option<CurrentTaskInfo>,
+    match repo.finish_task() {
-    pub tasks: Vec<Task>,
+        Err(repo::Error::NotFound) => {
-    pub finished_tasks_file_path: PathBuf,
+            eprintln!("You can use the finish subcommand only when you have an active task")
-    pub tasks_file_path: PathBuf,
-    pub current_task_info_file_path: PathBuf,
-}
-
-pub fn execute(mut req: Request) {
-    match req.current_task_info.take() {
-        None => {
-            panic!("You can use the finish subcommand only when you have an active task")
         }
-        Some(info) => {
+        Err(err) => eprintln!("Cannot finish the task: {}", err),
-            let mut finished_tasks: Vec<Task> = std::fs::File::open(&req.finished_tasks_file_path)
+        Ok(task) => {
-                .map(|file| serde_json::from_reader(file).unwrap())
+            println!("The task was finished successfully");
-                .unwrap_or_default();
+            println!("  {}", task.name);
-
+            if let Some(link) = task.link {
-            let task = req.tasks.remove(info.task_idx - 1);
+                println!("  link: {}", link);
-            finished_tasks.push(task);
+            }
-
-            let mut file = std::fs::File::create(req.tasks_file_path).unwrap();
-            file.write_all(&serde_json::to_vec(&req.tasks).unwrap())
-                .unwrap();
-
-            let mut file = std::fs::File::create(req.finished_tasks_file_path).unwrap();
-            file.write_all(&serde_json::to_vec(&finished_tasks).unwrap())
-                .unwrap();
-
-            let mut file = std::fs::File::create(req.current_task_info_file_path).unwrap();
-            file.write_all(&serde_json::to_vec(&req.current_task_info).unwrap())
-                .unwrap();
-
-            println!("finished");
         }
     }
 }

src/cli/list.rs

@@ -1,15 +1,23 @@
-use crate::{CurrentTaskInfo, Task};
+use crate::domain::CurrentTaskInfo;
+use crate::repo::Repository;
 
-pub struct Request {
+pub fn execute(repo: impl Repository) {
-    pub tasks: Vec<Task>,
+    let tasks = match repo.get_tasks() {
-    pub current_task_info: Option<CurrentTaskInfo>,
+        Ok(tasks) => tasks,
-}
+        Err(err) => return eprintln!("Cannot read tasks: {}", err),
+    };
 
-pub fn execute(req: Request) {
+    let cur_task = match repo.get_current_task_opt() {
-    for (i, task) in req.tasks.iter().enumerate() {
+        Ok(cur_task) => cur_task,
+        Err(err) => {
+            return eprintln!("Cannot read current task: {}", err);
+        }
+    };
+
+    for (i, task) in tasks.iter().enumerate() {
         let idx = i + 1;
 
-        match req.current_task_info {
+        match cur_task {
             Some(CurrentTaskInfo { task_idx, .. }) if task_idx == idx => print!("> "),
             _ => print!("  "),
         }

src/cli/pause.rs

@@ -1,20 +1,26 @@
-use std::io::Write;
+use crate::repo::{self, Repository};
-use std::path::PathBuf;
 
-use crate::CurrentTaskInfo;
+pub fn execute(repo: impl Repository) {
+    let task = match repo.stop_task() {
+        Err(repo::Error::NotFound) => {
+            return eprintln!("You can use the pause subcommand only when you have an active task")
+        }
+        Err(err) => {
+            return eprintln!("Cannot read current task: {}", err);
+        }
+        Ok(task) => task,
+    };
 
-pub struct Request {
+    match repo.stop_task() {
-    pub current_task_info: Option<CurrentTaskInfo>,
+        Ok(_) => {
-    pub current_task_info_file_path: PathBuf,
+            println!("The task was paused successfully");
-}
+            println!("  {}", task.name);
-
+            if let Some(link) = task.link {
-pub fn execute(mut req: Request) {
+                println!("  link: {}", link);
-    if req.current_task_info.take().is_none() {
+            }
-        panic!("You can use the pause subcommand only when you have an active task");
+        }
+        Err(err) => {
+            eprintln!("Cannot pause the task: {}", err);
+        }
     }
-
-    let mut file = std::fs::File::create(&req.current_task_info_file_path).unwrap();
-    file.write_all(&serde_json::to_vec(&req.current_task_info).unwrap())
-        .unwrap();
-    println!("paused");
 }

src/cli/priority.rs

@@ -1,8 +1,6 @@
-use crate::{CurrentTaskInfo, Task};
+use crate::repo::{self, Repository};
 
 use std::cmp::Ordering;
-use std::io::Write;
-use std::path::PathBuf;
 
 #[derive(clap::Args)]
 pub struct Args {
@@ -17,46 +15,61 @@ pub enum Priority {
     After { idx: usize },
 }
 
-pub struct Request {
+pub fn execute(repo: impl Repository, args: Args) {
-    pub args: Args,
+    match repo.get_current_task_opt() {
-    pub tasks: Vec<Task>,
+        Ok(Some(_)) => {
-    pub current_task_info: Option<CurrentTaskInfo>,
+            return eprintln!(
-    pub tasks_file_path: PathBuf,
+                "You can change priority only when you don't have an active task, yet"
-}
+            )
-
+        }
-pub fn execute(mut req: Request) {
+        Err(err) => {
-    if req.current_task_info.is_some() {
+            return eprintln!("Cannot read current task: {}", err);
-        panic!("You can change priority only when you don't have an active task, yet");
+        }
+        _ => {}
     }
 
-    let target_idx = req.args.idx;
+    let target_idx = args.idx;
-    if target_idx == 0 || target_idx > req.tasks.len() {
+
-        panic!("invalid index");
+    if let Err(err) = repo.get_task_opt(target_idx) {
+        return eprintln!("Task not found: {}", err);
     }
 
-    let idx = match req.args.priority {
+    let idx = match args.priority {
         Priority::Before { idx } | Priority::After { idx } => match target_idx.cmp(&idx) {
             Ordering::Equal => return,
             Ordering::Less => idx - 1,
             Ordering::Greater => idx,
         },
     };
-    if idx == 0 || idx > req.tasks.len() {
+    if let Err(err) = repo.get_task_opt(idx) {
-        panic!("invalid index");
+        return eprintln!("Task not found: {}", err);
     }
 
-    let target = req.tasks.remove(target_idx - 1);
+    let target = match repo.remove_task(target_idx) {
+        Ok(removed) => removed,
+        Err(err) => return eprintln!("Cannot remove the task: {}", err),
+    };
 
-    match req.args.priority {
+    let new_idx = match args.priority {
-        Priority::Before { .. } => {
+        Priority::Before { .. } => idx - 1,
-            req.tasks.insert(idx - 1, target);
+        Priority::After { .. } => idx,
+    };
+
+    let res = repo.insert_task(repo::InsertTaskData {
+        index: Some(new_idx),
+        name: target.name,
+        link: target.link,
+    });
+    match res {
+        Ok(task) => {
+            println!("The task was reordered successfully");
+            println!("  {}", task.name);
+            if let Some(link) = task.link {
+                println!("  link: {}", link);
+            }
         }
-        Priority::After { .. } => {
+        Err(err) => {
-            req.tasks.insert(idx, target);
+            eprintln!("Cannot reorder the task: {}", err);
         }
     }
-
-    let mut file = std::fs::File::create(&req.tasks_file_path).unwrap();
-    file.write_all(&serde_json::to_vec(&req.tasks).unwrap())
-        .unwrap();
 }

src/cli/remove.rs

@@ -1,31 +1,28 @@
+use crate::repo::{self, Repository};
 use std::io::{BufRead, Write};
-use std::path::PathBuf;
-
-use crate::{CurrentTaskInfo, Task};
 
 #[derive(clap::Args)]
 pub struct Args {
     idx: usize,
 }
 
-pub struct Request {
+pub fn execute(repo: impl Repository, args: Args) {
-    pub args: Args,
+    match repo.get_current_task_opt() {
-    pub current_task_info: Option<CurrentTaskInfo>,
+        Ok(Some(_)) => {
-    pub tasks: Vec<Task>,
+            return eprintln!("You can remove task only when you don't have an active task, yet");
-    pub tasks_file_path: PathBuf,
+        }
-}
+        Err(err) => {
-
+            return eprintln!("Cannot read current task: {}", err);
-pub fn execute(mut req: Request) {
+        }
-    if req.current_task_info.is_some() {
+        _ => {}
-        panic!("You can remove task only when you don't have an active task, yet");
     }
 
-    let idx = req.args.idx;
+    let task = match repo.get_task_opt(args.idx) {
-    if idx == 0 || idx > req.tasks.len() {
+        Ok(Some(task)) => task,
-        panic!("invalid index");
+        Ok(None) | Err(repo::Error::NotFound) => return eprintln!("Task not found"),
-    }
+        Err(err) => return eprintln!("Cannot get task: {}", err),
+    };
 
-    let task = &req.tasks[idx - 1];
     println!("You are deleting task:");
     println!("  {}", task.name);
     if let Some(ref link) = task.link {
@@ -46,11 +43,16 @@ pub fn execute(mut req: Request) {
         }
     }
 
-    req.tasks.remove(idx - 1);
+    match repo.remove_task(args.idx) {
-
+        Ok(_) => {
-    let mut file = std::fs::File::create(&req.tasks_file_path).unwrap();
+            println!("The task was removed successfully");
-    file.write_all(&serde_json::to_vec(&req.tasks).unwrap())
+            println!("  {}", task.name);
-        .unwrap();
+            if let Some(link) = task.link {
-
+                println!("  link: {}", link);
-    println!("removed");
+            }
+        }
+        Err(err) => {
+            eprintln!("Cannot remove the task: {}", err);
+        }
+    }
 }

src/cli/start.rs

@@ -1,5 +1,4 @@
-use crate::{CurrentTaskInfo, Task};
+use crate::repo::{self, Repository};
-use std::{io::Write, path::PathBuf};
 
 #[derive(clap::Args)]
 pub struct Args {
@@ -9,31 +8,20 @@ pub struct Args {
     idx: Option<usize>,
 }
 
-pub struct Request {
+pub fn execute(repo: impl Repository, args: Args) {
-    pub args: Args,
+    let task = match repo.start_task(args.idx.unwrap_or(1)) {
-    pub tasks: Vec<Task>,
+        Ok(task) => task,
-    pub current_task_info: Option<CurrentTaskInfo>,
+        Err(repo::Error::NotFound) => return eprintln!("Task not found"),
-    pub current_task_info_file_path: PathBuf,
+        Err(err) => return eprintln!("Cannot start task: {}", err),
-}
+    };
 
-pub fn execute(mut req: Request) {
+    println!("The task was started successfully");
-    let idx = req.args.idx.unwrap_or(1);
+    println!("  {}", task.name);
-    if idx == 0 || idx > req.tasks.len() {
+    if let Some(link) = task.link.as_ref() {
-        panic!("invalid index");
+        println!("  link: {}", link);
     }
-    let task = &req.tasks[idx - 1];
 
-    req.current_task_info.replace(CurrentTaskInfo {
+    if let (Some(link), true) = (task.link.as_ref(), args.open) {
-        task_idx: idx,
-        task: task.clone(),
-    });
-
-    let mut file = std::fs::File::create(&req.current_task_info_file_path).unwrap();
-    file.write_all(&serde_json::to_vec(&req.current_task_info).unwrap())
-        .unwrap();
-    println!("started");
-
-    if let (Some(link), true) = (task.link.as_ref(), req.args.open) {
         log::debug!("opening link...");
         std::process::Command::new("xdg-open")
             .arg(link)

src/cli/status.rs

@@ -1,16 +1,19 @@
-use crate::CurrentTaskInfo;
+use crate::repo::Repository;
 
-pub fn execute(current_task_info: Option<CurrentTaskInfo>) {
+pub fn execute(repo: impl Repository) {
-    match current_task_info {
+    match repo.get_current_task_opt() {
-        None => {
+        Ok(None) => {
             eprintln!("You don't have an active task.");
         }
-        Some(info) => {
+        Ok(Some(info)) => {
             println!("Information about your current task:");
             println!("  {}", info.task.name);
             if let Some(link) = info.task.link {
                 println!("  link: {}", link);
             }
         }
+        Err(err) => {
+            eprintln!("Cannot read current task: {}", err);
+        }
     }
 }

src/domain.rs

@@ -5,3 +5,9 @@ pub struct Task {
     pub link: Option<String>,
     // created_at
 }
+
+pub struct CurrentTaskInfo {
+    pub task_idx: usize,
+    pub task: Task,
+    // started_at
+}

src/main.rs

@@ -28,7 +28,6 @@
 
 use clap::Parser;
 use repo::fs::FsRepo;
-use serde::{Deserialize, Serialize};
 use xdg::BaseDirectories;
 
 mod cli;
@@ -39,84 +38,35 @@ fn main() {
     let args = cli::Args::parse();
 
     let xdg_dirs = BaseDirectories::with_prefix(env!("CARGO_PKG_NAME")).unwrap();
-
     let repo = FsRepo::new(xdg_dirs);
 
-    let finished_tasks_file_path = xdg_dirs.place_data_file("finished_data.json").unwrap();
-
-    let current_task_info_file_path = xdg_dirs.place_data_file("current.json").unwrap();
-    let current_task_info: Option<CurrentTaskInfo> =
-        std::fs::File::open(&current_task_info_file_path)
-            .map(|file| serde_json::from_reader(file).unwrap())
-            .unwrap_or_default();
-
     match args.command {
         cli::SubCommand::Add(args) => {
             cli::add::execute(repo, args);
         }
         cli::SubCommand::Edit(args) => {
-            cli::edit::execute(
+            cli::edit::execute(repo, args);
-                repo,
-                cli::edit::Request {
-                    args,
-                    current_task_info,
-                },
-            );
         }
         cli::SubCommand::Remove(args) => {
-            cli::remove::execute(cli::remove::Request {
+            cli::remove::execute(repo, args);
-                args,
-                current_task_info,
-                tasks,
-                tasks_file_path,
-            });
         }
         cli::SubCommand::List => {
-            cli::list::execute(cli::list::Request {
+            cli::list::execute(repo);
-                tasks,
-                current_task_info,
-            });
         }
         cli::SubCommand::Priority(args) => {
-            cli::priority::execute(cli::priority::Request {
+            cli::priority::execute(repo, args);
-                args,
-                tasks,
-                tasks_file_path,
-                current_task_info,
-            });
         }
         cli::SubCommand::Start(args) => {
-            cli::start::execute(cli::start::Request {
+            cli::start::execute(repo, args);
-                args,
-                tasks,
-                current_task_info,
-                current_task_info_file_path,
-            });
         }
         cli::SubCommand::Pause => {
-            cli::pause::execute(cli::pause::Request {
+            cli::pause::execute(repo);
-                current_task_info,
-                current_task_info_file_path,
-            });
         }
         cli::SubCommand::Finish => {
-            cli::finish::execute(cli::finish::Request {
+            cli::finish::execute(repo);
-                tasks,
-                current_task_info,
-                current_task_info_file_path,
-                tasks_file_path,
-                finished_tasks_file_path,
-            });
         }
         cli::SubCommand::Status => {
-            cli::status::execute(current_task_info);
+            cli::status::execute(repo);
         }
     }
 }
-
-#[derive(Deserialize, Serialize)]
-pub struct CurrentTaskInfo {
-    task_idx: usize,
-    task: Task,
-    // started_at
-}

src/repo.rs

@@ -22,18 +22,25 @@ impl std::fmt::Display for Error {
 impl std::error::Error for Error {}
 
 pub struct InsertTaskData {
-    name: String,
+    pub name: String,
-    link: Option<String>,
+    pub link: Option<String>,
+    pub index: Option<usize>,
 }
 
 pub struct UpdateTaskData {
-    name: Option<String>,
+    pub name: Option<String>,
-    link: Option<Option<String>>,
+    pub link: Option<Option<String>>,
 }
 
 pub trait Repository {
+    fn get_current_task_opt(&self) -> Result<Option<domain::CurrentTaskInfo>, Error>;
+
+    fn get_task_opt(&self, id: domain::TaskId) -> Result<Option<domain::Task>, Error>;
+
     fn get_tasks(&self) -> Result<Vec<domain::Task>, Error>;
 
+    fn remove_task(&self, id: domain::TaskId) -> Result<domain::Task, Error>;
+
     fn update_task(
         &self,
         id: domain::TaskId,
@@ -41,4 +48,10 @@ pub trait Repository {
     ) -> Result<domain::Task, Error>;
 
     fn insert_task(&self, insert_data: InsertTaskData) -> Result<domain::Task, Error>;
+
+    fn start_task(&self, id: domain::TaskId) -> Result<domain::Task, Error>;
+
+    fn stop_task(&self) -> Result<domain::Task, Error>;
+
+    fn finish_task(&self) -> Result<domain::Task, Error>;
 }

src/repo/fs.rs

@@ -23,7 +23,25 @@ impl From<Task> for domain::Task {
     }
 }
 
+#[derive(Deserialize, Serialize, Clone)]
+pub struct CurrentTaskInfo {
+    task_idx: usize,
+    task: Task,
+    // started_at
+}
+
+impl From<CurrentTaskInfo> for domain::CurrentTaskInfo {
+    fn from(repo: CurrentTaskInfo) -> Self {
+        domain::CurrentTaskInfo {
+            task_idx: repo.task_idx,
+            task: repo.task.into(),
+        }
+    }
+}
+
+const CURRENT_TASK_FILE: &str = "current.json";
 const DATA_FILE: &str = "data.json";
+const FINISHED_DATA_FILE: &str = "finished_data.json";
 
 pub struct FsRepo {
     xdg_dirs: BaseDirectories,
@@ -36,11 +54,37 @@ impl FsRepo {
 }
 
 impl Repository for FsRepo {
+    fn get_current_task_opt(&self) -> Result<Option<domain::CurrentTaskInfo>, Error> {
+        self.get_current_task_impl()
+            .map(|cur_task| cur_task.map(From::from))
+    }
+
+    fn get_task_opt(&self, id: domain::TaskId) -> Result<Option<domain::Task>, Error> {
+        let tasks = self.get_tasks_impl()?;
+        if id == 0 || id > tasks.len() {
+            return Err(Error::NotFound);
+        }
+
+        Ok(Some(tasks[id - 1].clone().into()))
+    }
+
     fn get_tasks(&self) -> Result<Vec<domain::Task>, Error> {
         self.get_tasks_impl()
             .map(|tasks| tasks.into_iter().map(Task::into).collect())
     }
 
+    fn remove_task(&self, id: domain::TaskId) -> Result<domain::Task, Error> {
+        let mut tasks = self.get_tasks_impl()?;
+        if id == 0 || id > tasks.len() {
+            return Err(Error::NotFound);
+        }
+
+        let removed = tasks.remove(id - 1);
+        self.save_tasks_impl(tasks)?;
+
+        Ok(removed.into())
+    }
+
     fn update_task(
         &self,
         id: domain::TaskId,
@@ -74,20 +118,86 @@ impl Repository for FsRepo {
         };
 
         let mut tasks = self.get_tasks_impl()?;
-        tasks.push(new_task.clone());
+
+        match insert_data.index {
+            None => tasks.push(new_task.clone()),
+            Some(idx) => tasks.insert(idx, new_task.clone()),
+        }
 
         self.save_tasks_impl(tasks)?;
 
         Ok(new_task.into())
     }
+
+    fn start_task(&self, id: domain::TaskId) -> Result<domain::Task, Error> {
+        let tasks = self.get_tasks_impl()?;
+        if id == 0 || id > tasks.len() {
+            return Err(Error::NotFound);
+        }
+
+        let task = &tasks[id - 1];
+        let mut cur_task = self.get_current_task_impl()?;
+
+        cur_task.replace(CurrentTaskInfo {
+            task_idx: id,
+            task: task.clone(),
+        });
+
+        self.save_current_task_impl(cur_task)?;
+        Ok(task.clone().into())
+    }
+
+    fn stop_task(&self) -> Result<domain::Task, Error> {
+        let mut cur_task = self.get_current_task_impl()?;
+        let old = cur_task.take().ok_or(Error::NotFound)?;
+        self.save_current_task_impl(cur_task)?;
+        Ok(old.task.into())
+    }
+
+    fn finish_task(&self) -> Result<domain::Task, Error> {
+        let mut cur_task = self.get_current_task_impl()?;
+        let old = cur_task.take().ok_or(Error::NotFound)?;
+
+        let mut finished_tasks = self.get_finished_tasks_impl()?;
+        let mut tasks = self.get_tasks_impl()?;
+
+        let task = tasks.remove(old.task_idx - 1);
+        finished_tasks.push(task.clone());
+
+        self.save_current_task_impl(cur_task)?;
+        self.save_tasks_impl(tasks)?;
+        self.save_finished_tasks_impl(finished_tasks)?;
+
+        Ok(task.into())
+    }
 }
 
 impl FsRepo {
+    fn get_current_task_impl(&self) -> Result<Option<CurrentTaskInfo>, Error> {
+        let file_path = self.xdg_dirs.get_data_file(CURRENT_TASK_FILE);
+        File::open(&file_path)
+            .ok()
+            .map(|file| serde_json::from_reader(file).map_err(|_| Error::InvalidData))
+            .transpose()
+    }
+
+    fn save_current_task_impl(&self, cur_task: Option<CurrentTaskInfo>) -> Result<(), Error> {
+        let file_path = self
+            .xdg_dirs
+            .place_data_file(CURRENT_TASK_FILE)
+            .map_err(|_| Error::InsertData)?;
+        let mut file = File::create(&file_path).map_err(|_| Error::InsertData)?;
+        let new_data = serde_json::to_vec(&cur_task).map_err(|_| Error::InvalidData)?;
+        file.write_all(&new_data).map_err(|_| Error::InsertData)
+    }
+
     fn get_tasks_impl(&self) -> Result<Vec<Task>, Error> {
         let file_path = self.xdg_dirs.get_data_file(DATA_FILE);
         File::open(&file_path)
-            .map_err(|_| Error::NotFound)
+            .ok()
-            .and_then(|file| serde_json::from_reader(file).map_err(|_| Error::InvalidData))
+            .map(|file| serde_json::from_reader(file).map_err(|_| Error::InvalidData))
+            .transpose()
+            .map(|tasks| tasks.unwrap_or_default())
     }
 
     fn save_tasks_impl(&self, tasks: Vec<Task>) -> Result<(), Error> {
@@ -99,4 +209,23 @@ impl FsRepo {
         let new_data = serde_json::to_vec(&tasks).map_err(|_| Error::InvalidData)?;
         file.write_all(&new_data).map_err(|_| Error::InsertData)
     }
+
+    fn get_finished_tasks_impl(&self) -> Result<Vec<Task>, Error> {
+        let file_path = self.xdg_dirs.get_data_file(FINISHED_DATA_FILE);
+        File::open(&file_path)
+            .ok()
+            .map(|file| serde_json::from_reader(file).map_err(|_| Error::InvalidData))
+            .transpose()
+            .map(|tasks| tasks.unwrap_or_default())
+    }
+
+    fn save_finished_tasks_impl(&self, tasks: Vec<Task>) -> Result<(), Error> {
+        let file_path = self
+            .xdg_dirs
+            .place_data_file(FINISHED_DATA_FILE)
+            .map_err(|_| Error::InsertData)?;
+        let mut file = File::create(&file_path).map_err(|_| Error::InsertData)?;
+        let new_data = serde_json::to_vec(&tasks).map_err(|_| Error::InvalidData)?;
+        file.write_all(&new_data).map_err(|_| Error::InsertData)
+    }
 }