Push newline after running an exercise instead on each rendering

Cargo.lock

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

exercises/20_threads/threads3.rs

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

solutions/20_threads/threads3.rs

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

src/cmd.rs

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

src/dev/check.rs

@@ -97,7 +97,12 @@ 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.");
         }
 
-        if !exercise_info.test && file_buf.contains("#[test]") {
+        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 {
             bail!("The file `{path}` contains tests annotated with `#[test]` but the exercise `{name}` has `test = false` in the `info.toml` file");
         }
 
@@ -160,61 +165,72 @@ fn check_unexpected_files(dir: &str, allowed_rust_files: &HashSet<PathBuf>) -> R
     Ok(())
 }
 
-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;
-                }
+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")?;
 
-                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),
+    let handles = info_file
+        .exercises
+        .iter()
+        .filter_map(|exercise_info| {
+            if exercise_info.skip_check_unsolved {
+                return None;
             }
+
+            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),
         }
 
-        Ok(())
-    })
+        write!(stdout, "\rProgress: {handle_num}/{n_handles}")?;
+        stdout.flush()?;
+        handle_num += 1;
+    }
+    stdout.write_all(b"\n")?;
+
+    Ok(())
 }
 
-fn check_exercises(info_file: &InfoFile, cmd_runner: &CmdRunner) -> Result<()> {
+fn check_exercises(info_file: &'static InfoFile, cmd_runner: &'static 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 info_file_paths = check_info_file_exercises(info_file)?;
-    let handle = thread::spawn(move || check_unexpected_files("exercises", &info_file_paths));
+    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)?;
 
-    check_exercises_unsolved(info_file, cmd_runner)?;
     handle.join().unwrap()
 }
 
 enum SolutionCheck {
     Success { sol_path: String },
-    MissingRequired,
     MissingOptional,
     RunFailure { output: Vec<u8> },
     Err(Error),
@@ -222,88 +238,96 @@ enum SolutionCheck {
 
 fn check_solutions(
     require_solutions: bool,
-    info_file: &InfoFile,
-    cmd_runner: &CmdRunner,
+    info_file: &'static InfoFile,
+    cmd_runner: &'static CmdRunner,
 ) -> Result<()> {
-    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 mut stdout = io::stdout().lock();
+    stdout.write_all(b"Running all solutions...\n")?;
 
-                        return SolutionCheck::MissingOptional;
+    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,
+                        ));
                     }
 
-                    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),
-                    }
-                })
+                    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),
+                }
             })
-            .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());
 
-        for (exercise_info, handle) in info_file.exercises.iter().zip(handles) {
-            let Ok(check_result) = handle.join() else {
+    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)?;
                 bail!(
-                    "Panic while trying to run the solution of the exericse {}",
+                    "Running the solution of the exercise {} failed with the error above",
                     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),
         }
 
-        let handle = s.spawn(move || check_unexpected_files("solutions", &sol_paths));
+        write!(stdout, "\rProgress: {handle_num}/{n_handles}")?;
+        stdout.flush()?;
+        handle_num += 1;
+    }
+    stdout.write_all(b"\n")?;
 
-        if !fmt_cmd
-            .status()
-            .context("Failed to run `rustfmt` on all solution files")?
-            .success()
-        {
-            bail!("Some solutions aren't formatted. Run `rustfmt` on them");
-        }
+    let handle = thread::spawn(move || check_unexpected_files("solutions", &sol_paths));
 
-        handle.join().unwrap()
-    })
+    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()
 }
 
 pub fn check(require_solutions: bool) -> Result<()> {
@@ -316,9 +340,12 @@ pub fn check(require_solutions: bool) -> Result<()> {
         check_cargo_toml(&info_file.exercises, "Cargo.toml", b"")?;
     }
 
-    let cmd_runner = CmdRunner::build()?;
-    check_exercises(&info_file, &cmd_runner)?;
-    check_solutions(require_solutions, &info_file, &cmd_runner)?;
+    // 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)?;
 
     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", "--show-output"]);
+                test_cmd.args(["--", "--color", "always", "--format", "pretty"]);
             }
             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!
-If you are developing third-party exercises, add at least one exercise before testing.";
+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()?;
-                ui_state = ui_state.with_updated_rows();
+                break;
             }
             _ => (),
         }

src/run.rs

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

src/watch/state.rs

@@ -56,10 +56,12 @@ 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()? {
@@ -121,11 +123,9 @@ 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!(
@@ -137,21 +137,20 @@ impl<'a> WatchState<'a> {
         }
 
         if self.done_status != DoneStatus::Pending {
-            writeln!(
-                self.writer,
-                "{}\n",
-                "Exercise done ✓
-When you are done experimenting, enter `n` to move on to the next exercise 🦀"
-                    .bold()
-                    .green(),
-            )?;
-        }
+            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(),
+                )?;
+            }
 
-        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(),
+                "When done experimenting, enter `n` to move on to the next exercise 🦀\n",
             )?;
         }