Document dev

src/cmd.rs

@@ -1,6 +1,8 @@
 use anyhow::{Context, Result};
 use std::{io::Read, path::Path, process::Command};
 
+// Run a command with a description for a possible error and append the merged stdout and stderr.
+// The boolean in the returned `Result` is true if the command's exit status is success.
 pub fn run_cmd(mut cmd: Command, description: &str, output: &mut Vec<u8>) -> Result<bool> {
     let (mut reader, writer) = os_pipe::pipe()
         .with_context(|| format!("Failed to create a pipe to run the command `{description}``"))?;
@@ -35,13 +37,18 @@ pub struct CargoCmd<'a> {
     pub args: &'a [&'a str],
     pub exercise_name: &'a str,
     pub description: &'a str,
+    // RUSTFLAGS="-A warnings"
     pub hide_warnings: bool,
+    // Added as `--target-dir` if `Self::dev` is true.
     pub target_dir: &'a Path,
+    // The output buffer to append the merged stdout and stderr.
     pub output: &'a mut Vec<u8>,
+    // true while developing Rustlings.
     pub dev: bool,
 }
 
 impl<'a> CargoCmd<'a> {
+    // Run `cargo SUBCOMMAND --bin EXERCISE_NAME … ARGS`.
     pub fn run(&mut self) -> Result<bool> {
         let mut cmd = Command::new("cargo");
         cmd.arg(self.subcommand);
@@ -68,3 +75,19 @@ impl<'a> CargoCmd<'a> {
         run_cmd(cmd, self.description, self.output)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_run_cmd() {
+        let mut cmd = Command::new("echo");
+        cmd.arg("Hello");
+
+        let mut output = Vec::with_capacity(8);
+        run_cmd(cmd, "echo …", &mut output).unwrap();
+
+        assert_eq!(output, b"Hello\n\n");
+    }
+}

src/dev.rs

@@ -1,7 +1,6 @@
-use std::path::PathBuf;
-
 use anyhow::{bail, Context, Result};
 use clap::Subcommand;
+use std::path::PathBuf;
 
 use crate::DEBUG_PROFILE;
 

src/dev/check.rs

@@ -12,32 +12,29 @@ use crate::{
     CURRENT_FORMAT_VERSION, DEBUG_PROFILE,
 };
 
+// Find a char that isn't allowed in the exercise's `name` or `dir`.
 fn forbidden_char(input: &str) -> Option<char> {
     input.chars().find(|c| *c != '_' && !c.is_alphanumeric())
 }
 
+// Check the info of all exercises and return their paths in a set.
 fn check_info_file_exercises(info_file: &InfoFile) -> Result<hashbrown::HashSet<PathBuf>> {
     let mut names = hashbrown::HashSet::with_capacity(info_file.exercises.len());
     let mut paths = hashbrown::HashSet::with_capacity(info_file.exercises.len());
 
     let mut file_buf = String::with_capacity(1 << 14);
     for exercise_info in &info_file.exercises {
-        if exercise_info.name.is_empty() {
+        let name = exercise_info.name.as_str();
+        if name.is_empty() {
             bail!("Found an empty exercise name in `info.toml`");
         }
-        if let Some(c) = forbidden_char(&exercise_info.name) {
+        if let Some(c) = forbidden_char(name) {
-            bail!(
+            bail!("Char `{c}` in the exercise name `{name}` is not allowed");
-                "Char `{c}` in the exercise name `{}` is not allowed",
-                exercise_info.name,
-            );
         }
 
         if let Some(dir) = &exercise_info.dir {
             if dir.is_empty() {
-                bail!(
+                bail!("The exercise `{name}` has an empty dir name in `info.toml`");
-                    "The exercise `{}` has an empty dir name in `info.toml`",
-                    exercise_info.name,
-                );
             }
             if let Some(c) = forbidden_char(dir) {
                 bail!("Char `{c}` in the exercise dir `{dir}` is not allowed");
@@ -45,14 +42,11 @@ fn check_info_file_exercises(info_file: &InfoFile) -> Result<hashbrown::HashSet<
         }
 
         if exercise_info.hint.trim().is_empty() {
-            bail!("The exercise `{}` has an empty hint. Please provide a hint or at least tell the user why a hint isn't needed for this exercise", exercise_info.name);
+            bail!("The exercise `{name}` has an empty hint. Please provide a hint or at least tell the user why a hint isn't needed for this exercise");
         }
 
-        if !names.insert(exercise_info.name.as_str()) {
+        if !names.insert(name) {
-            bail!(
+            bail!("The exercise name `{name}` is duplicated. Exercise names must all be unique");
-                "The exercise name `{}` is duplicated. Exercise names must all be unique",
-                exercise_info.name,
-            );
         }
 
         let path = exercise_info.path();
@@ -68,6 +62,10 @@ fn check_info_file_exercises(info_file: &InfoFile) -> Result<hashbrown::HashSet<
             bail!("The `main` function is missing in the file `{path}`.\nCreate at least an empty `main` function to avoid language server errors");
         }
 
+        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");
+        }
+
         file_buf.clear();
 
         paths.insert(PathBuf::from(path));
@@ -76,11 +74,12 @@ fn check_info_file_exercises(info_file: &InfoFile) -> Result<hashbrown::HashSet<
     Ok(paths)
 }
 
+// Check the `exercises` directory for unexpected files.
+fn check_unexpected_files(info_file_paths: &hashbrown::HashSet<PathBuf>) -> Result<()> {
     fn unexpected_file(path: &Path) -> Error {
         anyhow!("Found the file `{}`. Only `README.md` and Rust files related to an exercise in `info.toml` are allowed in the `exercises` directory", path.display())
     }
 
-fn check_exercise_dir_files(info_file_paths: &hashbrown::HashSet<PathBuf>) -> Result<()> {
     for entry in read_dir("exercises").context("Failed to open the `exercises` directory")? {
         let entry = entry.context("Failed to read the `exercises` directory")?;
 
@@ -132,11 +131,12 @@ fn check_exercises(info_file: &InfoFile) -> Result<()> {
     }
 
     let info_file_paths = check_info_file_exercises(info_file)?;
-    check_exercise_dir_files(&info_file_paths)?;
+    check_unexpected_files(&info_file_paths)?;
 
     Ok(())
 }
 
+// Check that the Cargo.toml file is up-to-date.
 fn check_cargo_toml(
     exercise_infos: &[ExerciseInfo],
     current_cargo_toml: &str,
@@ -163,6 +163,7 @@ pub fn check() -> Result<()> {
     let info_file = InfoFile::parse()?;
     check_exercises(&info_file)?;
 
+    // A hack to make `cargo run -- dev check` work when developing Rustlings.
     if DEBUG_PROFILE {
         check_cargo_toml(
             &info_file.exercises,

src/dev/new.rs

@@ -8,6 +8,7 @@ use std::{
 
 use crate::CURRENT_FORMAT_VERSION;
 
+// Create a directory relative to the current directory and print its path.
 fn create_rel_dir(dir_name: &str, current_dir: &str) -> Result<()> {
     create_dir(dir_name)
         .with_context(|| format!("Failed to create the directory {current_dir}/{dir_name}"))?;
@@ -15,6 +16,7 @@ fn create_rel_dir(dir_name: &str, current_dir: &str) -> Result<()> {
     Ok(())
 }
 
+// Write a file relative to the current directory and print its path.
 fn write_rel_file<C>(file_name: &str, current_dir: &str, content: C) -> Result<()>
 where
     C: AsRef<[u8]>,
@@ -27,13 +29,13 @@ where
 }
 
 pub fn new(path: &Path, no_git: bool) -> Result<()> {
-    let dir_name = path.to_string_lossy();
+    let dir_path_str = path.to_string_lossy();
 
-    create_dir(path).with_context(|| format!("Failed to create the directory {dir_name}"))?;
+    create_dir(path).with_context(|| format!("Failed to create the directory {dir_path_str}"))?;
-    println!("Created the directory {dir_name}");
+    println!("Created the directory {dir_path_str}");
 
     set_current_dir(path)
-        .with_context(|| format!("Failed to set {dir_name} as the current directory"))?;
+        .with_context(|| format!("Failed to set {dir_path_str} as the current directory"))?;
 
     if !no_git
         && !Command::new("git")
@@ -42,28 +44,28 @@ pub fn new(path: &Path, no_git: bool) -> Result<()> {
             .context("Failed to run `git init`")?
             .success()
     {
-        bail!("`git init` didn't run successfully. See the error message above");
+        bail!("`git init` didn't run successfully. See the possible error message above");
     }
 
-    write_rel_file(".gitignore", &dir_name, GITIGNORE)?;
+    write_rel_file(".gitignore", &dir_path_str, GITIGNORE)?;
 
-    create_rel_dir("exercises", &dir_name)?;
+    create_rel_dir("exercises", &dir_path_str)?;
-    create_rel_dir("solutions", &dir_name)?;
+    create_rel_dir("solutions", &dir_path_str)?;
 
     write_rel_file(
         "info.toml",
-        &dir_name,
+        &dir_path_str,
         format!("{INFO_FILE_BEFORE_FORMAT_VERSION}{CURRENT_FORMAT_VERSION}{INFO_FILE_AFTER_FORMAT_VERSION}"),
     )?;
 
-    write_rel_file("Cargo.toml", &dir_name, CARGO_TOML)?;
+    write_rel_file("Cargo.toml", &dir_path_str, CARGO_TOML)?;
 
-    write_rel_file("README.md", &dir_name, README)?;
+    write_rel_file("README.md", &dir_path_str, README)?;
 
-    create_rel_dir(".vscode", &dir_name)?;
+    create_rel_dir(".vscode", &dir_path_str)?;
     write_rel_file(
         ".vscode/extensions.json",
-        &dir_name,
+        &dir_path_str,
         crate::init::VS_CODE_EXTENSIONS_JSON,
     )?;
 
@@ -137,8 +139,7 @@ const README: &str = "# Rustlings 🦀
 
 Welcome to these third-party Rustlings exercises 😃
 
-First,
+First, [install Rustlings using the official instructions in the README of the Rustlings project](https://github.com/rust-lang/rustlings) ✅
-[install Rustlings using the official instructions in the README of the Rustlings project](https://github.com/rust-lang/rustlings) ✅
 
 Then, open your terminal in this directory and run `rustlings` to get started with the exercises 🚀
 ";

src/dev/update.rs

@@ -1,6 +1,5 @@
-use std::fs;
-
 use anyhow::{Context, Result};
+use std::fs;
 
 use crate::{
     cargo_toml::updated_cargo_toml,
@@ -8,6 +7,7 @@ use crate::{
     DEBUG_PROFILE,
 };
 
+// Update the `Cargo.toml` file.
 fn update_cargo_toml(
     exercise_infos: &[ExerciseInfo],
     current_cargo_toml: &str,
@@ -26,6 +26,7 @@ fn update_cargo_toml(
 pub fn update() -> Result<()> {
     let info_file = InfoFile::parse()?;
 
+    // A hack to make `cargo run -- dev update` work when developing Rustlings.
     if DEBUG_PROFILE {
         update_cargo_toml(
             &info_file.exercises,