Cargo.lock

@@ -368,9 +368,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.158"
+version = "0.2.156"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d8adc4bb1803a324070e64a98ae98f38934d91957a99cfb3a43dcbc01bc56439"
+checksum = "a5f43f184355eefb8d17fc948dbecf6c13be3c141f20d834ae842193a448c72a"
 
 [[package]]
 name = "libredox"
@@ -746,9 +746,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "2.0.75"
+version = "2.0.74"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f6af063034fc1935ede7be0122941bafa9bacb949334d090b77ca98b5817c7d9"
+checksum = "1fceb41e3d546d0bd83421d3409b1460cc7444cd389341a4c880fe7a042cb3d7"
 dependencies = [
  "proc-macro2",
  "quote",

exercises/20_threads/threads3.rs

@@ -1,6 +1,7 @@
 use std::{sync::mpsc, thread, time::Duration};
 
 struct Queue {
+    length: u32,
     first_half: Vec<u32>,
     second_half: Vec<u32>,
 }
@@ -8,6 +9,7 @@ struct Queue {
 impl Queue {
     fn new() -> Self {
         Self {
+            length: 10,
             first_half: vec![1, 2, 3, 4, 5],
             second_half: vec![6, 7, 8, 9, 10],
         }
@@ -46,15 +48,17 @@ mod tests {
     fn threads3() {
         let (tx, rx) = mpsc::channel();
         let queue = Queue::new();
+        let queue_length = queue.length;
 
         send_tx(queue, tx);
 
-        let mut received = Vec::with_capacity(10);
-        for value in rx {
-            received.push(value);
+        let mut total_received: u32 = 0;
+        for received in rx {
+            println!("Got: {received}");
+            total_received += 1;
         }
 
-        received.sort();
-        assert_eq!(received, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
+        println!("Number of received values: {total_received}");
+        assert_eq!(total_received, queue_length);
     }
 }

solutions/20_threads/threads3.rs

@@ -1,6 +1,7 @@
 use std::{sync::mpsc, thread, time::Duration};
 
 struct Queue {
+    length: u32,
     first_half: Vec<u32>,
     second_half: Vec<u32>,
 }
@@ -8,6 +9,7 @@ struct Queue {
 impl Queue {
     fn new() -> Self {
         Self {
+            length: 10,
             first_half: vec![1, 2, 3, 4, 5],
             second_half: vec![6, 7, 8, 9, 10],
         }
@@ -48,15 +50,17 @@ mod tests {
     fn threads3() {
         let (tx, rx) = mpsc::channel();
         let queue = Queue::new();
+        let queue_length = queue.length;
 
         send_tx(queue, tx);
 
-        let mut received = Vec::with_capacity(10);
-        for value in rx {
-            received.push(value);
+        let mut total_received: u32 = 0;
+        for received in rx {
+            println!("Got: {received}");
+            total_received += 1;
         }
 
-        received.sort();
-        assert_eq!(received, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
+        println!("Number of received values: {total_received}");
+        assert_eq!(total_received, queue_length);
     }
 }

src/cmd.rs

@@ -74,14 +74,12 @@ impl CmdRunner {
             bail!("The command `cargo metadata …` failed. Are you in the `rustlings/` directory?");
         }
 
-        let metadata: CargoMetadata = serde_json::de::from_slice(&metadata_output.stdout)
+        let target_dir = serde_json::de::from_slice::<CargoMetadata>(&metadata_output.stdout)
             .context(
                 "Failed to read the field `target_directory` from the output of the command `cargo metadata …`",
-            )?;
+            )?.target_directory;
 
-        Ok(Self {
-            target_dir: metadata.target_directory,
-        })
+        Ok(Self { target_dir })
     }
 
     pub fn cargo<'out>(

src/dev/check.rs

@@ -97,12 +97,7 @@ fn check_info_file_exercises(info_file: &InfoFile) -> Result<HashSet<PathBuf>> {
             bail!("Didn't find any `// TODO` comment in the file `{path}`.\nYou need to have at least one such comment to guide the user.");
         }
 
-        let contains_tests = file_buf.contains("#[test]\n");
-        if exercise_info.test {
-            if !contains_tests {
-                bail!("The file `{path}` doesn't contain any tests. If you don't want to add tests to this exercise, set `test = false` for this exercise in the `info.toml` file");
-            }
-        } else if contains_tests {
+        if !exercise_info.test && file_buf.contains("#[test]") {
             bail!("The file `{path}` contains tests annotated with `#[test]` but the exercise `{name}` has `test = false` in the `info.toml` file");
         }
 
@@ -165,72 +160,61 @@ fn check_unexpected_files(dir: &str, allowed_rust_files: &HashSet<PathBuf>) -> R
     Ok(())
 }
 
-fn check_exercises_unsolved(
-    info_file: &'static InfoFile,
-    cmd_runner: &'static CmdRunner,
-) -> Result<()> {
-    let mut stdout = io::stdout().lock();
-    stdout.write_all(b"Running all exercises to check that they aren't already solved...\n")?;
+fn check_exercises_unsolved(info_file: &InfoFile, cmd_runner: &CmdRunner) -> Result<()> {
+    println!(
+        "Running all exercises to check that they aren't already solved. This may take a while…\n",
+    );
+    thread::scope(|s| {
+        let handles = info_file
+            .exercises
+            .iter()
+            .filter_map(|exercise_info| {
+                if exercise_info.skip_check_unsolved {
+                    return None;
+                }
 
-    let handles = info_file
-        .exercises
-        .iter()
-        .filter_map(|exercise_info| {
-            if exercise_info.skip_check_unsolved {
-                return None;
+                Some((
+                    exercise_info.name.as_str(),
+                    s.spawn(|| exercise_info.run_exercise(None, cmd_runner)),
+                ))
+            })
+            .collect::<Vec<_>>();
+
+        for (exercise_name, handle) in handles {
+            let Ok(result) = handle.join() else {
+                bail!("Panic while trying to run the exericse {exercise_name}");
+            };
+
+            match result {
+                Ok(true) => bail!(
+                    "The exercise {exercise_name} is already solved.\n{SKIP_CHECK_UNSOLVED_HINT}",
+                ),
+                Ok(false) => (),
+                Err(e) => return Err(e),
             }
-
-            Some((
-                exercise_info.name.as_str(),
-                thread::spawn(|| exercise_info.run_exercise(None, cmd_runner)),
-            ))
-        })
-        .collect::<Vec<_>>();
-
-    let n_handles = handles.len();
-    write!(stdout, "Progress: 0/{n_handles}")?;
-    stdout.flush()?;
-    let mut handle_num = 1;
-
-    for (exercise_name, handle) in handles {
-        let Ok(result) = handle.join() else {
-            bail!("Panic while trying to run the exericse {exercise_name}");
-        };
-
-        match result {
-            Ok(true) => {
-                bail!("The exercise {exercise_name} is already solved.\n{SKIP_CHECK_UNSOLVED_HINT}",)
-            }
-            Ok(false) => (),
-            Err(e) => return Err(e),
         }
 
-        write!(stdout, "\rProgress: {handle_num}/{n_handles}")?;
-        stdout.flush()?;
-        handle_num += 1;
-    }
-    stdout.write_all(b"\n")?;
-
-    Ok(())
+        Ok(())
+    })
 }
 
-fn check_exercises(info_file: &'static InfoFile, cmd_runner: &'static CmdRunner) -> Result<()> {
+fn check_exercises(info_file: &InfoFile, cmd_runner: &CmdRunner) -> Result<()> {
     match info_file.format_version.cmp(&CURRENT_FORMAT_VERSION) {
         Ordering::Less => bail!("`format_version` < {CURRENT_FORMAT_VERSION} (supported version)\nPlease migrate to the latest format version"),
         Ordering::Greater => bail!("`format_version` > {CURRENT_FORMAT_VERSION} (supported version)\nTry updating the Rustlings program"),
         Ordering::Equal => (),
     }
 
-    let handle = thread::spawn(move || check_exercises_unsolved(info_file, cmd_runner));
-
     let info_file_paths = check_info_file_exercises(info_file)?;
-    check_unexpected_files("exercises", &info_file_paths)?;
+    let handle = thread::spawn(move || check_unexpected_files("exercises", &info_file_paths));
 
+    check_exercises_unsolved(info_file, cmd_runner)?;
     handle.join().unwrap()
 }
 
 enum SolutionCheck {
     Success { sol_path: String },
+    MissingRequired,
     MissingOptional,
     RunFailure { output: Vec<u8> },
     Err(Error),
@@ -238,96 +222,88 @@ enum SolutionCheck {
 
 fn check_solutions(
     require_solutions: bool,
-    info_file: &'static InfoFile,
-    cmd_runner: &'static CmdRunner,
+    info_file: &InfoFile,
+    cmd_runner: &CmdRunner,
 ) -> Result<()> {
-    let mut stdout = io::stdout().lock();
-    stdout.write_all(b"Running all solutions...\n")?;
+    println!("Running all solutions. This may take a while…\n");
+    thread::scope(|s| {
+        let handles = info_file
+            .exercises
+            .iter()
+            .map(|exercise_info| {
+                s.spawn(|| {
+                    let sol_path = exercise_info.sol_path();
+                    if !Path::new(&sol_path).exists() {
+                        if require_solutions {
+                            return SolutionCheck::MissingRequired;
+                        }
 
-    let handles = info_file
-        .exercises
-        .iter()
-        .map(|exercise_info| {
-            thread::spawn(move || {
-                let sol_path = exercise_info.sol_path();
-                if !Path::new(&sol_path).exists() {
-                    if require_solutions {
-                        return SolutionCheck::Err(anyhow!(
-                            "The solution of the exercise {} is missing",
-                            exercise_info.name,
-                        ));
+                        return SolutionCheck::MissingOptional;
                     }
 
-                    return SolutionCheck::MissingOptional;
-                }
-
-                let mut output = Vec::with_capacity(OUTPUT_CAPACITY);
-                match exercise_info.run_solution(Some(&mut output), cmd_runner) {
-                    Ok(true) => SolutionCheck::Success { sol_path },
-                    Ok(false) => SolutionCheck::RunFailure { output },
-                    Err(e) => SolutionCheck::Err(e),
-                }
+                    let mut output = Vec::with_capacity(OUTPUT_CAPACITY);
+                    match exercise_info.run_solution(Some(&mut output), cmd_runner) {
+                        Ok(true) => SolutionCheck::Success { sol_path },
+                        Ok(false) => SolutionCheck::RunFailure { output },
+                        Err(e) => SolutionCheck::Err(e),
+                    }
+                })
             })
-        })
-        .collect::<Vec<_>>();
+            .collect::<Vec<_>>();
 
-    let mut sol_paths = hash_set_with_capacity(info_file.exercises.len());
-    let mut fmt_cmd = Command::new("rustfmt");
-    fmt_cmd
-        .arg("--check")
-        .arg("--edition")
-        .arg("2021")
-        .arg("--color")
-        .arg("always")
-        .stdin(Stdio::null());
+        let mut sol_paths = hash_set_with_capacity(info_file.exercises.len());
+        let mut fmt_cmd = Command::new("rustfmt");
+        fmt_cmd
+            .arg("--check")
+            .arg("--edition")
+            .arg("2021")
+            .arg("--color")
+            .arg("always")
+            .stdin(Stdio::null());
 
-    let n_handles = handles.len();
-    write!(stdout, "Progress: 0/{n_handles}")?;
-    stdout.flush()?;
-    let mut handle_num = 1;
-
-    for (exercise_info, handle) in info_file.exercises.iter().zip(handles) {
-        let Ok(check_result) = handle.join() else {
-            bail!(
-                "Panic while trying to run the solution of the exericse {}",
-                exercise_info.name,
-            );
-        };
-
-        match check_result {
-            SolutionCheck::Success { sol_path } => {
-                fmt_cmd.arg(&sol_path);
-                sol_paths.insert(PathBuf::from(sol_path));
-            }
-            SolutionCheck::MissingOptional => (),
-            SolutionCheck::RunFailure { output } => {
-                stdout.write_all(b"\n\n")?;
-                stdout.write_all(&output)?;
+        for (exercise_info, handle) in info_file.exercises.iter().zip(handles) {
+            let Ok(check_result) = handle.join() else {
                 bail!(
-                    "Running the solution of the exercise {} failed with the error above",
+                    "Panic while trying to run the solution of the exericse {}",
                     exercise_info.name,
                 );
+            };
+
+            match check_result {
+                SolutionCheck::Success { sol_path } => {
+                    fmt_cmd.arg(&sol_path);
+                    sol_paths.insert(PathBuf::from(sol_path));
+                }
+                SolutionCheck::MissingRequired => {
+                    bail!(
+                        "The solution of the exercise {} is missing",
+                        exercise_info.name,
+                    );
+                }
+                SolutionCheck::MissingOptional => (),
+                SolutionCheck::RunFailure { output } => {
+                    io::stderr().lock().write_all(&output)?;
+                    bail!(
+                        "Running the solution of the exercise {} failed with the error above",
+                        exercise_info.name,
+                    );
+                }
+                SolutionCheck::Err(e) => return Err(e),
             }
-            SolutionCheck::Err(e) => return Err(e),
         }
 
-        write!(stdout, "\rProgress: {handle_num}/{n_handles}")?;
-        stdout.flush()?;
-        handle_num += 1;
-    }
-    stdout.write_all(b"\n")?;
+        let handle = s.spawn(move || check_unexpected_files("solutions", &sol_paths));
 
-    let handle = thread::spawn(move || check_unexpected_files("solutions", &sol_paths));
+        if !fmt_cmd
+            .status()
+            .context("Failed to run `rustfmt` on all solution files")?
+            .success()
+        {
+            bail!("Some solutions aren't formatted. Run `rustfmt` on them");
+        }
 
-    if !fmt_cmd
-        .status()
-        .context("Failed to run `rustfmt` on all solution files")?
-        .success()
-    {
-        bail!("Some solutions aren't formatted. Run `rustfmt` on them");
-    }
-
-    handle.join().unwrap()
+        handle.join().unwrap()
+    })
 }
 
 pub fn check(require_solutions: bool) -> Result<()> {
@@ -340,12 +316,9 @@ pub fn check(require_solutions: bool) -> Result<()> {
         check_cargo_toml(&info_file.exercises, "Cargo.toml", b"")?;
     }
 
-    // Leaking is fine since they are used until the end of the program.
-    let cmd_runner = Box::leak(Box::new(CmdRunner::build()?));
-    let info_file = Box::leak(Box::new(info_file));
-
-    check_exercises(info_file, cmd_runner)?;
-    check_solutions(require_solutions, info_file, cmd_runner)?;
+    let cmd_runner = CmdRunner::build()?;
+    check_exercises(&info_file, &cmd_runner)?;
+    check_solutions(require_solutions, &info_file, &cmd_runner)?;
 
     println!("Everything looks fine!");
 

src/exercise.rs

@@ -98,7 +98,7 @@ pub trait RunnableExercise {
             let output_is_some = output.is_some();
             let mut test_cmd = cmd_runner.cargo("test", bin_name, output.as_deref_mut());
             if output_is_some {
-                test_cmd.args(["--", "--color", "always", "--format", "pretty"]);
+                test_cmd.args(["--", "--color", "always", "--show-output"]);
             }
             let test_success = test_cmd.run("cargo test …")?;
             if !test_success {

src/info_file.rs

@@ -135,4 +135,4 @@ impl InfoFile {
 }
 
 const NO_EXERCISES_ERR: &str = "There are no exercises yet!
-Add at least one exercise before testing.";
+If you are developing third-party exercises, add at least one exercise before testing.";

src/list.rs

@@ -75,7 +75,7 @@ fn handle_list(app_state: &mut AppState, stdout: &mut StdoutLock) -> Result<()>
             }
             KeyCode::Char('c') => {
                 ui_state.selected_to_current_exercise()?;
-                break;
+                ui_state = ui_state.with_updated_rows();
             }
             _ => (),
         }

src/run.rs

@@ -33,21 +33,18 @@ pub fn run(app_state: &mut AppState) -> Result<()> {
     )?;
 
     if let Some(solution_path) = app_state.current_solution_path()? {
-        writeln!(
-            stdout,
-            "\n{} for comparison: {}\n",
-            "Solution".bold(),
-            style(TerminalFileLink(&solution_path)).underlined().cyan(),
-        )?;
+        println!(
+            "\nA solution file can be found at {}\n",
+            style(TerminalFileLink(&solution_path)).underlined().green(),
+        );
     }
 
     match app_state.done_current_exercise(&mut stdout)? {
         ExercisesProgress::AllDone => (),
-        ExercisesProgress::CurrentPending | ExercisesProgress::NewPending => writeln!(
-            stdout,
+        ExercisesProgress::CurrentPending | ExercisesProgress::NewPending => println!(
             "Next exercise: {}",
             app_state.current_exercise().terminal_link(),
-        )?,
+        ),
     }
 
     Ok(())

src/watch/state.rs

@@ -56,12 +56,10 @@ impl<'a> WatchState<'a> {
             "\nChecking the exercise `{}`. Please wait…",
             self.app_state.current_exercise().name,
         )?;
-
         let success = self
             .app_state
             .current_exercise()
             .run_exercise(Some(&mut self.output), self.app_state.cmd_runner())?;
-        self.output.push(b'\n');
         if success {
             self.done_status =
                 if let Some(solution_path) = self.app_state.current_solution_path()? {
@@ -123,9 +121,11 @@ impl<'a> WatchState<'a> {
     pub fn render(&mut self) -> Result<()> {
         // Prevent having the first line shifted if clearing wasn't successful.
         self.writer.write_all(b"\n")?;
+
         clear_terminal(&mut self.writer)?;
 
         self.writer.write_all(&self.output)?;
+        self.writer.write_all(b"\n")?;
 
         if self.show_hint {
             writeln!(
@@ -137,20 +137,21 @@ impl<'a> WatchState<'a> {
         }
 
         if self.done_status != DoneStatus::Pending {
-            writeln!(self.writer, "{}", "Exercise done ✓".bold().green())?;
-
-            if let DoneStatus::DoneWithSolution(solution_path) = &self.done_status {
-                writeln!(
-                    self.writer,
-                    "{} for comparison: {}",
-                    "Solution".bold(),
-                    style(TerminalFileLink(solution_path)).underlined().cyan(),
-                )?;
-            }
-
             writeln!(
                 self.writer,
-                "When done experimenting, enter `n` to move on to the next exercise 🦀\n",
+                "{}\n",
+                "Exercise done ✓
+When you are done experimenting, enter `n` to move on to the next exercise 🦀"
+                    .bold()
+                    .green(),
+            )?;
+        }
+
+        if let DoneStatus::DoneWithSolution(solution_path) = &self.done_status {
+            writeln!(
+                self.writer,
+                "A solution file can be found at {}\n",
+                style(TerminalFileLink(solution_path)).underlined().green(),
             )?;
         }