Merge e59c65cf45 into baeeff389c

Improvement to "check all exercises"

clippy.toml

@@ -13,4 +13,6 @@ disallowed-methods = [
   # Use `thread::Builder::spawn` instead and handle the error.
   "std::thread::spawn",
   "std::thread::Scope::spawn",
+  # Return `ExitCode` instead.
+  "std::process::exit",
 ]

dev/Cargo.toml

@@ -26,6 +26,8 @@ bin = [
   { name = "functions4_sol", path = "../solutions/02_functions/functions4.rs" },
   { name = "functions5", path = "../exercises/02_functions/functions5.rs" },
   { name = "functions5_sol", path = "../solutions/02_functions/functions5.rs" },
+  { name = "functions6", path = "../exercises/02_functions/functions6.rs" },
+  { name = "functions6_sol", path = "../solutions/02_functions/functions6.rs" },
   { name = "if1", path = "../exercises/03_if/if1.rs" },
   { name = "if1_sol", path = "../solutions/03_if/if1.rs" },
   { name = "if2", path = "../exercises/03_if/if2.rs" },
@@ -60,6 +62,8 @@ bin = [
   { name = "move_semantics4_sol", path = "../solutions/06_move_semantics/move_semantics4.rs" },
   { name = "move_semantics5", path = "../exercises/06_move_semantics/move_semantics5.rs" },
   { name = "move_semantics5_sol", path = "../solutions/06_move_semantics/move_semantics5.rs" },
+  { name = "move_semantics6", path = "../exercises/06_move_semantics/move_semantics6.rs" },
+  { name = "move_semantics6_sol", path = "../solutions/06_move_semantics/move_semantics6.rs" },
   { name = "structs1", path = "../exercises/07_structs/structs1.rs" },
   { name = "structs1_sol", path = "../solutions/07_structs/structs1.rs" },
   { name = "structs2", path = "../exercises/07_structs/structs2.rs" },

exercises/02_functions/README.md

@@ -1,8 +1,9 @@
 # Functions
 
 Here, you'll learn how to write functions and how the Rust compiler can help you debug errors even
-in more complex code.
+in more complex code. You will also learn what is the difference with closures.
 
 ## Further information
 
 - [How Functions Work](https://doc.rust-lang.org/book/ch03-03-how-functions-work.html)
+- [Closures](https://doc.rust-lang.org/book/ch13-01-closures.html)

exercises/02_functions/functions6.rs

@@ -0,0 +1,19 @@
+// functions6.rs
+//
+// Here you can practice special functions called `closures`, that can capture
+// variables of their parent context.
+// Fix the code below to make it compile, without changing the two closure
+// definitions.
+//
+// Execute `rustlings hint functions6` or use the `hint` watch subcommand for
+// some hints.
+
+fn main() {
+  // TODO: ensure the definition of captured variable
+  let closure_1 = |input_var: u32| -> u32 {input_var + outer_var};
+  println!("Closure#1 returns {}", closure_1(5));
+
+  let closure_2 = |input_var| println!("Closure#2 (input_var {})", input_var);
+  closure_2(2);
+  closure_2("5"); // TODO: look at the captured variable type here
+}

exercises/06_move_semantics/move_semantics6.rs

@@ -0,0 +1,25 @@
+// move_semantics6.rs
+//
+// Here you will practice how mutable/immutable borrowing works in the context
+// of a closure.
+//
+// Try to fix this code to make it compile and not panic.
+// You can't change anything except removing 1 line.
+//
+// Execute `rustlings hint move_semantics7` or use the `hint` watch subcommand
+// for a hint.
+
+fn main() {
+  let mut counter = 0;
+
+  let mut increment = || {
+    counter += 1;
+    println!("counter equals {}", counter);
+  };
+
+  increment();
+  let _reborrowed_counter = &counter; // TODO: figure out where to put this borrowing instruction
+  increment();
+
+  assert_eq!(counter, 2);
+}

exercises/README.md

@@ -3,7 +3,7 @@
 | Exercise               | Book Chapter        |
 | ---------------------- | ------------------- |
 | variables              | §3.1                |
-| functions              | §3.3                |
+| functions              | §3.3, §13.1         |
 | if                     | §3.5                |
 | primitive_types        | §3.2, §4.3          |
 | vecs                   | §8.1                |

rustlings-macros/info.toml

@@ -187,6 +187,20 @@ There are two solutions:
 1. Add the `return` keyword before `num * num;`
 2. Remove the semicolon `;` after `num * num`"""
 
+[[exercises]]
+name = "functions6"
+dir = "02_functions"
+test = false
+hint = """
+Hint FIX #1: Closures can capture variables defined in the outer context.
+
+Hint FIX #2: Closures can infer both input and returned types, when they are not
+specified in the signature. But the closure cannot be reused with different
+input types.
+
+Read more about closures in the rust book dedicated section:
+https://doc.rust-lang.org/book/ch13-01-closures.html"""
+
 # IF
 
 [[exercises]]
@@ -391,6 +405,18 @@ The first problem is that `get_char` is taking ownership of the string. So
 Once you've fixed that, `string_uppercase`'s function signature will also need
 to be adjusted."""
 
+[[exercises]]
+name = "move_semantics6"
+dir = "06_move_semantics"
+test = false
+hint = """
+When a closure captures a variable to modify it, it actually borrows that variable
+as a mutable reference. In this exercise, the closure mutably borrows the `counter`
+variable, thus, any attempt to borrow `counter` between closure calls leads to an error.
+
+You cannot immutably borrow a variable if a mutable closure is
+called later in the scope."""
+
 # STRUCTS
 
 [[exercises]]

solutions/02_functions/functions6.rs

@@ -0,0 +1,9 @@
+fn main() {
+    let outer_var = 1;
+    let closure_1 = |input_var: u32| -> u32 { input_var + outer_var };
+    println!("Closure#1 returns {}", closure_1(5));
+
+    let closure_2 = |input_var| println!("Closure#2 (input_var {})", input_var);
+    closure_2(2);
+    closure_2(5);
+}

solutions/06_move_semantics/move_semantics6.rs

@@ -0,0 +1,14 @@
+fn main() {
+    let mut counter = 0;
+
+    let mut increment = || {
+        counter += 1;
+        println!("counter equals {}", counter);
+    };
+
+    increment();
+    increment();
+    let _reborrowed_counter = &counter;
+
+    assert_eq!(counter, 2);
+}

src/app_state.rs

@@ -1,10 +1,15 @@
-use anyhow::{bail, Context, Result};
+use anyhow::{bail, Context, Error, Result};
+use crossterm::{cursor, terminal, QueueableCommand};
 use std::{
     env,
     fs::{File, OpenOptions},
-    io::{self, Read, Seek, StdoutLock, Write},
+    io::{Read, Seek, StdoutLock, Write},
     path::{Path, MAIN_SEPARATOR_STR},
     process::{Command, Stdio},
+    sync::{
+        atomic::{AtomicUsize, Ordering::Relaxed},
+        mpsc,
+    },
     thread,
 };
 
@@ -15,10 +20,11 @@ use crate::{
     embedded::EMBEDDED_FILES,
     exercise::{Exercise, RunnableExercise},
     info_file::ExerciseInfo,
-    term,
+    term::{self, CheckProgressVisualizer},
 };
 
 const STATE_FILE_NAME: &str = ".rustlings-state.txt";
+const DEFAULT_CHECK_PARALLELISM: usize = 8;
 
 #[must_use]
 pub enum ExercisesProgress {
@@ -35,10 +41,12 @@ pub enum StateFileStatus {
     NotRead,
 }
 
-enum AllExercisesCheck {
+#[derive(Clone, Copy)]
-    Pending(usize),
+pub enum CheckProgress {
-    AllDone,
+    None,
-    CheckedUntil(usize),
+    Checking,
+    Done,
+    Pending,
 }
 
 pub struct AppState {
@@ -194,6 +202,11 @@ impl AppState {
         self.n_done
     }
 
+    #[inline]
+    pub fn n_pending(&self) -> u16 {
+        self.exercises.len() as u16 - self.n_done
+    }
+
     #[inline]
     pub fn current_exercise(&self) -> &Exercise {
         &self.exercises[self.current_exercise_ind]
@@ -270,15 +283,31 @@ impl AppState {
         self.write()
     }
 
-    pub fn set_pending(&mut self, exercise_ind: usize) -> Result<()> {
+    // Set the status of an exercise without saving. Returns `true` if the
+    // status actually changed (and thus needs saving later).
+    pub fn set_status(&mut self, exercise_ind: usize, done: bool) -> Result<bool> {
         let exercise = self
             .exercises
             .get_mut(exercise_ind)
             .context(BAD_INDEX_ERR)?;
 
-        if exercise.done {
+        if exercise.done == done {
-            exercise.done = false;
+            return Ok(false);
+        }
+
+        exercise.done = done;
+        if done {
+            self.n_done += 1;
+        } else {
             self.n_done -= 1;
+        }
+
+        Ok(true)
+    }
+
+    // Set the status of an exercise to "pending" and save.
+    pub fn set_pending(&mut self, exercise_ind: usize) -> Result<()> {
+        if self.set_status(exercise_ind, false)? {
             self.write()?;
         }
 
@@ -379,63 +408,114 @@ impl AppState {
         }
     }
 
-    // Return the exercise index of the first pending exercise found.
+    fn check_all_exercises_impl(&mut self, stdout: &mut StdoutLock) -> Result<Option<usize>> {
-    fn check_all_exercises(&self, stdout: &mut StdoutLock) -> Result<Option<usize>> {
+        let term_width = terminal::size()
-        stdout.write_all(FINAL_CHECK_MSG)?;
+            .context("Failed to get the terminal size")?
-        let n_exercises = self.exercises.len();
+            .0;
+        let mut progress_visualizer = CheckProgressVisualizer::build(stdout, term_width)?;
 
-        let status = thread::scope(|s| {
+        let next_exercise_ind = AtomicUsize::new(0);
-            let handles = self
+        let mut progresses = vec![CheckProgress::None; self.exercises.len()];
-                .exercises
+
-                .iter()
+        thread::scope(|s| {
-                .map(|exercise| {
+            let (exercise_progress_sender, exercise_progress_receiver) = mpsc::channel();
+            let n_threads = thread::available_parallelism()
+                .map_or(DEFAULT_CHECK_PARALLELISM, |count| count.get());
+
+            for _ in 0..n_threads {
+                let exercise_progress_sender = exercise_progress_sender.clone();
+                let next_exercise_ind = &next_exercise_ind;
+                let slf = &self;
                 thread::Builder::new()
-                        .spawn_scoped(s, || exercise.run_exercise(None, &self.cmd_runner))
+                    .spawn_scoped(s, move || loop {
+                        let exercise_ind = next_exercise_ind.fetch_add(1, Relaxed);
+                        let Some(exercise) = slf.exercises.get(exercise_ind) else {
+                            // No more exercises.
+                            break;
+                        };
+
+                        if exercise_progress_sender
+                            .send((exercise_ind, CheckProgress::Checking))
+                            .is_err()
+                        {
+                            break;
+                        };
+
+                        let success = exercise.run_exercise(None, &slf.cmd_runner);
+                        let progress = match success {
+                            Ok(true) => CheckProgress::Done,
+                            Ok(false) => CheckProgress::Pending,
+                            Err(_) => CheckProgress::None,
+                        };
+
+                        if exercise_progress_sender
+                            .send((exercise_ind, progress))
+                            .is_err()
+                        {
+                            break;
+                        }
                     })
-                .collect::<Vec<_>>();
+                    .context("Failed to spawn a thread to check all exercises")?;
-
-            for (exercise_ind, spawn_res) in handles.into_iter().enumerate() {
-                write!(stdout, "\rProgress: {exercise_ind}/{n_exercises}")?;
-                stdout.flush()?;
-
-                let Ok(handle) = spawn_res else {
-                    return Ok(AllExercisesCheck::CheckedUntil(exercise_ind));
-                };
-
-                let Ok(success) = handle.join().unwrap() else {
-                    return Ok(AllExercisesCheck::CheckedUntil(exercise_ind));
-                };
-
-                if !success {
-                    return Ok(AllExercisesCheck::Pending(exercise_ind));
-                }
             }
 
-            Ok::<_, io::Error>(AllExercisesCheck::AllDone)
+            // Drop this sender to detect when the last thread is done.
+            drop(exercise_progress_sender);
+
+            while let Ok((exercise_ind, progress)) = exercise_progress_receiver.recv() {
+                progresses[exercise_ind] = progress;
+                progress_visualizer.update(&progresses)?;
+            }
+
+            Ok::<_, Error>(())
         })?;
 
-        let mut exercise_ind = match status {
+        let mut first_pending_exercise_ind = None;
-            AllExercisesCheck::Pending(exercise_ind) => return Ok(Some(exercise_ind)),
+        for exercise_ind in 0..progresses.len() {
-            AllExercisesCheck::AllDone => return Ok(None),
+            match progresses[exercise_ind] {
-            AllExercisesCheck::CheckedUntil(ind) => ind,
+                CheckProgress::Done => {
-        };
+                    self.set_status(exercise_ind, true)?;
-
+                }
-        // We got an error while checking all exercises in parallel.
+                CheckProgress::Pending => {
-        // This could be because we exceeded the limit of open file descriptors.
+                    self.set_status(exercise_ind, false)?;
-        // Therefore, try to continue the check sequentially.
+                    if first_pending_exercise_ind.is_none() {
-        for exercise in &self.exercises[exercise_ind..] {
+                        first_pending_exercise_ind = Some(exercise_ind);
-            write!(stdout, "\rProgress: {exercise_ind}/{n_exercises}")?;
+                    }
-            stdout.flush()?;
+                }
+                CheckProgress::None | CheckProgress::Checking => {
+                    // If we got an error while checking all exercises in parallel,
+                    // it could be because we exceeded the limit of open file descriptors.
+                    // Therefore, try running exercises with errors sequentially.
+                    progresses[exercise_ind] = CheckProgress::Checking;
+                    progress_visualizer.update(&progresses)?;
 
+                    let exercise = &self.exercises[exercise_ind];
                     let success = exercise.run_exercise(None, &self.cmd_runner)?;
-            if !success {
+                    if success {
-                return Ok(Some(exercise_ind));
+                        progresses[exercise_ind] = CheckProgress::Done;
+                    } else {
+                        progresses[exercise_ind] = CheckProgress::Pending;
+                        if first_pending_exercise_ind.is_none() {
+                            first_pending_exercise_ind = Some(exercise_ind);
+                        }
+                    }
+                    self.set_status(exercise_ind, success)?;
+                    progress_visualizer.update(&progresses)?;
+                }
+            }
         }
 
-            exercise_ind += 1;
+        self.write()?;
+
+        Ok(first_pending_exercise_ind)
     }
 
-        Ok(None)
+    // Return the exercise index of the first pending exercise found.
+    pub fn check_all_exercises(&mut self, stdout: &mut StdoutLock) -> Result<Option<usize>> {
+        stdout.queue(cursor::Hide)?;
+        let res = self.check_all_exercises_impl(stdout);
+        stdout.queue(cursor::Show)?;
+
+        res
     }
 
     /// Mark the current exercise as done and move on to the next pending exercise if one exists.
@@ -462,20 +542,18 @@ impl AppState {
             stdout.write_all(b"\n")?;
         }
 
-        if let Some(pending_exercise_ind) = self.check_all_exercises(stdout)? {
+        if let Some(first_pending_exercise_ind) = self.check_all_exercises(stdout)? {
-            stdout.write_all(b"\n\n")?;
+            self.set_current_exercise_ind(first_pending_exercise_ind)?;
 
-            self.current_exercise_ind = pending_exercise_ind;
-            self.exercises[pending_exercise_ind].done = false;
-            // All exercises were marked as done.
-            self.n_done -= 1;
-            self.write()?;
             return Ok(ExercisesProgress::NewPending);
         }
 
-        // Write that the last exercise is done.
+        self.render_final_message(stdout)?;
-        self.write()?;
 
+        Ok(ExercisesProgress::AllDone)
+    }
+
+    pub fn render_final_message(&self, stdout: &mut StdoutLock) -> Result<()> {
         clear_terminal(stdout)?;
         stdout.write_all(FENISH_LINE.as_bytes())?;
 
@@ -485,15 +563,12 @@ impl AppState {
             stdout.write_all(b"\n")?;
         }
 
-        Ok(ExercisesProgress::AllDone)
+        Ok(())
     }
 }
 
 const BAD_INDEX_ERR: &str = "The current exercise index is higher than the number of exercises";
 const STATE_FILE_HEADER: &[u8] = b"DON'T EDIT THIS FILE!\n\n";
-const FINAL_CHECK_MSG: &[u8] = b"All exercises seem to be done.
-Recompiling and running all exercises to make sure that all of them are actually done.
-";
 const FENISH_LINE: &str = "+----------------------------------------------------+
 |          You made it to the Fe-nish line!          |
 +--------------------------  ------------------------+

src/main.rs

@@ -4,7 +4,7 @@ use clap::{Parser, Subcommand};
 use std::{
     io::{self, IsTerminal, Write},
     path::Path,
-    process::exit,
+    process::ExitCode,
 };
 use term::{clear_terminal, press_enter_prompt};
 
@@ -47,6 +47,8 @@ enum Subcommands {
         /// The name of the exercise
         name: Option<String>,
     },
+    /// Check all the exercises, marking them as done or pending accordingly.
+    CheckAll,
     /// Reset a single exercise
     Reset {
         /// The name of the exercise
@@ -62,22 +64,26 @@ enum Subcommands {
     Dev(DevCommands),
 }
 
-fn main() -> Result<()> {
+fn main() -> Result<ExitCode> {
     let args = Args::parse();
 
     if cfg!(not(debug_assertions)) && Path::new("dev/rustlings-repo.txt").exists() {
         bail!("{OLD_METHOD_ERR}");
     }
 
+    'priority_cmd: {
         match args.command {
-        Some(Subcommands::Init) => return init::init().context("Initialization failed"),
+            Some(Subcommands::Init) => init::init().context("Initialization failed")?,
-        Some(Subcommands::Dev(dev_command)) => return dev_command.run(),
+            Some(Subcommands::Dev(dev_command)) => dev_command.run()?,
-        _ => (),
+            _ => break 'priority_cmd,
+        }
+
+        return Ok(ExitCode::SUCCESS);
     }
 
     if !Path::new("exercises").is_dir() {
         println!("{PRE_INIT_MSG}");
-        exit(1);
+        return Ok(ExitCode::FAILURE);
     }
 
     let info_file = InfoFile::parse()?;
@@ -136,7 +142,35 @@ fn main() -> Result<()> {
             if let Some(name) = name {
                 app_state.set_current_exercise_by_name(&name)?;
             }
-            run::run(&mut app_state)?;
+            return run::run(&mut app_state);
+        }
+        Some(Subcommands::CheckAll) => {
+            let mut stdout = io::stdout().lock();
+            if let Some(first_pending_exercise_ind) = app_state.check_all_exercises(&mut stdout)? {
+                if app_state.current_exercise().done {
+                    app_state.set_current_exercise_ind(first_pending_exercise_ind)?;
+                }
+
+                stdout.write_all(b"\n\n")?;
+                let pending = app_state.n_pending();
+                if pending == 1 {
+                    stdout.write_all(b"One exercise pending: ")?;
+                } else {
+                    write!(
+                        stdout,
+                        "{pending}/{} exercises pending. The first: ",
+                        app_state.exercises().len(),
+                    )?;
+                }
+                app_state
+                    .current_exercise()
+                    .terminal_file_link(&mut stdout)?;
+                stdout.write_all(b"\n")?;
+
+                return Ok(ExitCode::FAILURE);
+            } else {
+                app_state.render_final_message(&mut stdout)?;
+            }
         }
         Some(Subcommands::Reset { name }) => {
             app_state.set_current_exercise_by_name(&name)?;
@@ -153,7 +187,7 @@ fn main() -> Result<()> {
         Some(Subcommands::Init | Subcommands::Dev(_)) => (),
     }
 
-    Ok(())
+    Ok(ExitCode::SUCCESS)
 }
 
 const OLD_METHOD_ERR: &str =

src/run.rs

@@ -5,7 +5,7 @@ use crossterm::{
 };
 use std::{
     io::{self, Write},
-    process::exit,
+    process::ExitCode,
 };
 
 use crate::{
@@ -13,7 +13,7 @@ use crate::{
     exercise::{solution_link_line, RunnableExercise, OUTPUT_CAPACITY},
 };
 
-pub fn run(app_state: &mut AppState) -> Result<()> {
+pub fn run(app_state: &mut AppState) -> Result<ExitCode> {
     let exercise = app_state.current_exercise();
     let mut output = Vec::with_capacity(OUTPUT_CAPACITY);
     let success = exercise.run_exercise(Some(&mut output), app_state.cmd_runner())?;
@@ -29,7 +29,8 @@ pub fn run(app_state: &mut AppState) -> Result<()> {
             .current_exercise()
             .terminal_file_link(&mut stdout)?;
         stdout.write_all(b" with errors\n")?;
-        exit(1);
+
+        return Ok(ExitCode::FAILURE);
     }
 
     stdout.queue(SetForegroundColor(Color::Green))?;
@@ -55,5 +56,5 @@ pub fn run(app_state: &mut AppState) -> Result<()> {
         ExercisesProgress::AllDone => (),
     }
 
-    Ok(())
+    Ok(ExitCode::SUCCESS)
 }

src/term.rs

@@ -1,6 +1,6 @@
 use crossterm::{
     cursor::MoveTo,
-    style::{Attribute, Color, SetAttribute, SetForegroundColor},
+    style::{Attribute, Color, ResetColor, SetAttribute, SetForegroundColor},
     terminal::{Clear, ClearType},
     Command, QueueableCommand,
 };
@@ -9,6 +9,8 @@ use std::{
     io::{self, BufRead, StdoutLock, Write},
 };
 
+use crate::app_state::CheckProgress;
+
 pub struct MaxLenWriter<'a, 'b> {
     pub stdout: &'a mut StdoutLock<'b>,
     len: usize,
@@ -85,12 +87,84 @@ impl<'a> CountedWrite<'a> for StdoutLock<'a> {
     }
 }
 
-/// Terminal progress bar to be used when not using Ratataui.
+pub struct CheckProgressVisualizer<'a, 'b> {
+    stdout: &'a mut StdoutLock<'b>,
+    n_cols: usize,
+}
+
+impl<'a, 'b> CheckProgressVisualizer<'a, 'b> {
+    const CHECKING_COLOR: Color = Color::Blue;
+    const DONE_COLOR: Color = Color::Green;
+    const PENDING_COLOR: Color = Color::Red;
+
+    pub fn build(stdout: &'a mut StdoutLock<'b>, term_width: u16) -> io::Result<Self> {
+        clear_terminal(stdout)?;
+        stdout.write_all("Checking all exercises…\n".as_bytes())?;
+
+        // Legend
+        stdout.write_all(b"Color of exercise number: ")?;
+        stdout.queue(SetForegroundColor(Self::CHECKING_COLOR))?;
+        stdout.write_all(b"Checking")?;
+        stdout.queue(ResetColor)?;
+        stdout.write_all(b" - ")?;
+        stdout.queue(SetForegroundColor(Self::DONE_COLOR))?;
+        stdout.write_all(b"Done")?;
+        stdout.queue(ResetColor)?;
+        stdout.write_all(b" - ")?;
+        stdout.queue(SetForegroundColor(Self::PENDING_COLOR))?;
+        stdout.write_all(b"Pending")?;
+        stdout.queue(ResetColor)?;
+        stdout.write_all(b"\n")?;
+
+        // Exercise numbers with up to 3 digits.
+        // +1 because the last column doesn't end with a whitespace.
+        let n_cols = usize::from(term_width + 1) / 4;
+
+        Ok(Self { stdout, n_cols })
+    }
+
+    pub fn update(&mut self, progresses: &[CheckProgress]) -> io::Result<()> {
+        self.stdout.queue(MoveTo(0, 2))?;
+
+        let mut exercise_num = 1;
+        for exercise_progress in progresses {
+            match exercise_progress {
+                CheckProgress::None => (),
+                CheckProgress::Checking => {
+                    self.stdout
+                        .queue(SetForegroundColor(Self::CHECKING_COLOR))?;
+                }
+                CheckProgress::Done => {
+                    self.stdout.queue(SetForegroundColor(Self::DONE_COLOR))?;
+                }
+                CheckProgress::Pending => {
+                    self.stdout.queue(SetForegroundColor(Self::PENDING_COLOR))?;
+                }
+            }
+
+            write!(self.stdout, "{exercise_num:<3}")?;
+            self.stdout.queue(ResetColor)?;
+
+            if exercise_num != progresses.len() {
+                if exercise_num % self.n_cols == 0 {
+                    self.stdout.write_all(b"\n")?;
+                } else {
+                    self.stdout.write_all(b" ")?;
+                }
+
+                exercise_num += 1;
+            }
+        }
+
+        self.stdout.flush()
+    }
+}
+
 pub fn progress_bar<'a>(
     writer: &mut impl CountedWrite<'a>,
     progress: u16,
     total: u16,
-    line_width: u16,
+    term_width: u16,
 ) -> io::Result<()> {
     debug_assert!(total < 1000);
     debug_assert!(progress <= total);
@@ -101,7 +175,7 @@ pub fn progress_bar<'a>(
     const WRAPPER_WIDTH: u16 = PREFIX_WIDTH + POSTFIX_WIDTH;
     const MIN_LINE_WIDTH: u16 = WRAPPER_WIDTH + 4;
 
-    if line_width < MIN_LINE_WIDTH {
+    if term_width < MIN_LINE_WIDTH {
         writer.write_ascii(b"Progress: ")?;
         // Integers are in ASCII.
         return writer.write_ascii(format!("{progress}/{total}").as_bytes());
@@ -110,7 +184,7 @@ pub fn progress_bar<'a>(
     let stdout = writer.stdout();
     stdout.write_all(PREFIX)?;
 
-    let width = line_width - WRAPPER_WIDTH;
+    let width = term_width - WRAPPER_WIDTH;
     let filled = (width * progress) / total;
 
     stdout.queue(SetForegroundColor(Color::Green))?;

src/watch.rs

@@ -103,6 +103,13 @@ fn run_watch(
             WatchEvent::Input(InputEvent::Run) => watch_state.run_current_exercise(&mut stdout)?,
             WatchEvent::Input(InputEvent::Hint) => watch_state.show_hint(&mut stdout)?,
             WatchEvent::Input(InputEvent::List) => return Ok(WatchExit::List),
+            WatchEvent::Input(InputEvent::CheckAll) => match watch_state
+                .check_all_exercises(&mut stdout)?
+            {
+                ExercisesProgress::AllDone => break,
+                ExercisesProgress::NewPending => watch_state.run_current_exercise(&mut stdout)?,
+                ExercisesProgress::CurrentPending => watch_state.render(&mut stdout)?,
+            },
             WatchEvent::Input(InputEvent::Reset) => watch_state.reset_exercise(&mut stdout)?,
             WatchEvent::Input(InputEvent::Quit) => {
                 stdout.write_all(QUIT_MSG)?;

src/watch/state.rs

@@ -157,8 +157,9 @@ impl<'a> WatchState<'a> {
 
     /// Move on to the next exercise if the current one is done.
     pub fn next_exercise(&mut self, stdout: &mut StdoutLock) -> Result<ExercisesProgress> {
-        if self.done_status == DoneStatus::Pending {
+        match self.done_status {
-            return Ok(ExercisesProgress::CurrentPending);
+            DoneStatus::DoneWithSolution(_) | DoneStatus::DoneWithoutSolution => (),
+            DoneStatus::Pending => return Ok(ExercisesProgress::CurrentPending),
         }
 
         self.app_state.done_current_exercise::<true>(stdout)
@@ -195,6 +196,11 @@ impl<'a> WatchState<'a> {
         stdout.queue(ResetColor)?;
         stdout.write_all(b":list / ")?;
 
+        stdout.queue(SetAttribute(Attribute::Bold))?;
+        stdout.write_all(b"c")?;
+        stdout.queue(ResetColor)?;
+        stdout.write_all(b":check all / ")?;
+
         stdout.queue(SetAttribute(Attribute::Bold))?;
         stdout.write_all(b"x")?;
         stdout.queue(ResetColor)?;
@@ -274,6 +280,22 @@ impl<'a> WatchState<'a> {
         Ok(())
     }
 
+    pub fn check_all_exercises(&mut self, stdout: &mut StdoutLock) -> Result<ExercisesProgress> {
+        if let Some(first_pending_exercise_ind) = self.app_state.check_all_exercises(stdout)? {
+            // Only change exercise if the current one is done.
+            if self.app_state.current_exercise().done {
+                self.app_state
+                    .set_current_exercise_ind(first_pending_exercise_ind)?;
+                Ok(ExercisesProgress::NewPending)
+            } else {
+                Ok(ExercisesProgress::CurrentPending)
+            }
+        } else {
+            self.app_state.render_final_message(stdout)?;
+            Ok(ExercisesProgress::AllDone)
+        }
+    }
+
     pub fn update_term_width(&mut self, width: u16, stdout: &mut StdoutLock) -> io::Result<()> {
         if self.term_width != width {
             self.term_width = width;

src/watch/terminal_event.rs

@@ -11,6 +11,7 @@ pub enum InputEvent {
     Run,
     Hint,
     List,
+    CheckAll,
     Reset,
     Quit,
 }
@@ -37,6 +38,7 @@ pub fn terminal_event_handler(
                     KeyCode::Char('r') if manual_run => InputEvent::Run,
                     KeyCode::Char('h') => InputEvent::Hint,
                     KeyCode::Char('l') => break WatchEvent::Input(InputEvent::List),
+                    KeyCode::Char('c') => InputEvent::CheckAll,
                     KeyCode::Char('x') => {
                         if sender.send(WatchEvent::Input(InputEvent::Reset)).is_err() {
                             return;