Respect the target-dir config and show tests' output

8 files changed, 176 insertions, 158 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 5767267..f9b48bd 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -272,16 +272,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5443807d6dff69373d433ab9ef5378ad8df50ca6298caf15de6e52e24aaf54d5"
 
 [[package]]
-name = "errno"
-version = "0.3.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a258e46cdc063eb8519c00b9fc845fc47bcfca4130e2f08e88665ceda8474245"
-dependencies = [
- "libc",
- "windows-sys 0.52.0",
-]
-
-[[package]]
 name = "filetime"
 version = "0.2.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -334,15 +324,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
 [[package]]
-name = "home"
-version = "0.5.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e3d1354bf6b7235cb4a0576c2619fd4ed18183f689b12b006a0ee7329eeff9a5"
-dependencies = [
- "windows-sys 0.52.0",
-]
-
-[[package]]
 name = "indexmap"
 version = "2.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -420,12 +401,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c198f91728a82281a64e1f4f9eeb25d82cb32a5de251c6bd1b5154d63a8e7bd"
 
 [[package]]
-name = "linux-raw-sys"
-version = "0.4.13"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "01cda141df6706de531b6c46c3a33ecca755538219bd484262fa09410c13539c"
-
-[[package]]
 name = "lock_api"
 version = "0.4.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -665,19 +640,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "adad44e29e4c806119491a7f06f03de4d1af22c3a680dd47f1e6e179439d1f56"
 
 [[package]]
-name = "rustix"
-version = "0.38.34"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "70dc5ec042f7a43c4a73241207cecc9873a06d45debb38b329f8541d85c2730f"
-dependencies = [
- "bitflags 2.5.0",
- "errno",
- "libc",
- "linux-raw-sys",
- "windows-sys 0.52.0",
-]
-
-[[package]]
 name = "rustlings"
 version = "6.0.0-beta.3"
 dependencies = [
@@ -692,8 +654,8 @@ dependencies = [
  "ratatui",
  "rustlings-macros",
  "serde",
+ "serde_json",
  "toml_edit",
- "which",
 ]
 
 [[package]]
@@ -753,6 +715,17 @@ dependencies = [
 ]
 
 [[package]]
+name = "serde_json"
+version = "1.0.116"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3e17db7126d17feb94eb3fad46bf1a96b034e8aacbc2e775fe81505f8b0b2813"
+dependencies = [
+ "itoa",
+ "ryu",
+ "serde",
+]
+
+[[package]]
 name = "serde_spanned"
 version = "0.6.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -936,18 +909,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
 [[package]]
-name = "which"
-version = "6.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8211e4f58a2b2805adfbefbc07bab82958fc91e3836339b1ab7ae32465dce0d7"
-dependencies = [
- "either",
- "home",
- "rustix",
- "winsafe",
-]
-
-[[package]]
 name = "winapi"
 version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1127,12 +1088,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "winsafe"
-version = "0.0.19"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d135d17ab770252ad95e9a872d365cf3090e3be864a34ab46f48555993efc904"
-
-[[package]]
 name = "zerocopy"
 version = "0.7.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/Cargo.toml b/Cargo.toml
index 1bc26c9..a77c84f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -56,9 +56,9 @@ notify-debouncer-mini = "0.4.1"
 os_pipe = "1.1.5"
 ratatui = "0.26.2"
 rustlings-macros = { path = "rustlings-macros", version = "=6.0.0-beta.3" }
+serde_json = "1.0.116"
 serde.workspace = true
 toml_edit.workspace = true
-which = "6.0.1"
 
 [dev-dependencies]
 assert_cmd = "2.0.14"
diff --git a/src/app_state.rs b/src/app_state.rs
index 476b5a9..b980bdb 100644
--- a/src/app_state.rs
+++ b/src/app_state.rs
@@ -7,7 +7,7 @@ use crossterm::{
 use std::{
     fs::{self, File},
     io::{Read, StdoutLock, Write},
-    path::Path,
+    path::{Path, PathBuf},
     process::{Command, Stdio},
 };
 
@@ -39,6 +39,7 @@ pub struct AppState {
     final_message: String,
     file_buf: Vec<u8>,
     official_exercises: bool,
+    target_dir: PathBuf,
 }
 
 impl AppState {
@@ -90,6 +91,7 @@ impl AppState {
     pub fn new(
         exercise_infos: Vec<ExerciseInfo>,
         final_message: String,
+        target_dir: PathBuf,
     ) -> (Self, StateFileStatus) {
         let exercises = exercise_infos
             .into_iter()
@@ -127,6 +129,7 @@ impl AppState {
             final_message,
             file_buf: Vec::with_capacity(2048),
             official_exercises: !Path::new("info.toml").exists(),
+            target_dir,
         };
 
         let state_file_status = slf.update_from_file();
@@ -154,6 +157,11 @@ impl AppState {
         &self.exercises[self.current_exercise_ind]
     }
 
+    #[inline]
+    pub fn target_dir(&self) -> &Path {
+        &self.target_dir
+    }
+
     pub fn set_current_exercise_ind(&mut self, ind: usize) -> Result<()> {
         if ind >= self.exercises.len() {
             bail!(BAD_INDEX_ERR);
@@ -313,7 +321,7 @@ impl AppState {
                 write!(writer, "Running {exercise} ... ")?;
                 writer.flush()?;
 
-                let success = exercise.run(&mut output)?;
+                let success = exercise.run(&mut output, &self.target_dir)?;
                 if !success {
                     writeln!(writer, "{}\n", "FAILED".red())?;
 
diff --git a/src/cmd.rs b/src/cmd.rs
new file mode 100644
index 0000000..28f21c5
--- /dev/null
+++ b/src/cmd.rs
@@ -0,0 +1,70 @@
+use anyhow::{Context, Result};
+use std::{io::Read, path::Path, process::Command};
+
+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}``"))?;
+
+    let writer_clone = writer.try_clone().with_context(|| {
+        format!("Failed to clone the pipe writer for the command `{description}`")
+    })?;
+
+    let mut handle = cmd
+        .stdout(writer_clone)
+        .stderr(writer)
+        .spawn()
+        .with_context(|| format!("Failed to run the command `{description}`"))?;
+
+    // Prevent pipe deadlock.
+    drop(cmd);
+
+    reader
+        .read_to_end(output)
+        .with_context(|| format!("Failed to read the output of the command `{description}`"))?;
+
+    output.push(b'\n');
+
+    handle
+        .wait()
+        .with_context(|| format!("Failed to wait on the command `{description}` to exit"))
+        .map(|status| status.success())
+}
+
+pub struct CargoCmd<'a> {
+    pub subcommand: &'a str,
+    pub args: &'a [&'a str],
+    pub exercise_name: &'a str,
+    pub description: &'a str,
+    pub hide_warnings: bool,
+    pub target_dir: &'a Path,
+    pub output: &'a mut Vec<u8>,
+    pub dev: bool,
+}
+
+impl<'a> CargoCmd<'a> {
+    pub fn run(&mut self) -> Result<bool> {
+        let mut cmd = Command::new("cargo");
+        cmd.arg(self.subcommand);
+
+        // A hack to make `cargo run` work when developing Rustlings.
+        if self.dev {
+            cmd.arg("--manifest-path")
+                .arg("dev/Cargo.toml")
+                .arg("--target-dir")
+                .arg(self.target_dir);
+        }
+
+        cmd.arg("--color")
+            .arg("always")
+            .arg("-q")
+            .arg("--bin")
+            .arg(self.exercise_name)
+            .args(self.args);
+
+        if self.hide_warnings {
+            cmd.env("RUSTFLAGS", "-A warnings");
+        }
+
+        run_cmd(cmd, self.description, self.output)
+    }
+}
diff --git a/src/exercise.rs b/src/exercise.rs
index 50f360e..23dae6f 100644
--- a/src/exercise.rs
+++ b/src/exercise.rs
@@ -1,57 +1,21 @@
-use anyhow::{Context, Result};
+use anyhow::Result;
 use crossterm::style::{style, StyledContent, Stylize};
 use std::{
     fmt::{self, Display, Formatter},
-    io::{Read, Write},
-    process::{Command, Stdio},
+    io::Write,
+    path::{Path, PathBuf},
+    process::Command,
 };
 
-use crate::{in_official_repo, terminal_link::TerminalFileLink, DEBUG_PROFILE};
+use crate::{
+    cmd::{run_cmd, CargoCmd},
+    in_official_repo,
+    terminal_link::TerminalFileLink,
+    DEBUG_PROFILE,
+};
 
 pub const OUTPUT_CAPACITY: usize = 1 << 14;
 
-fn run_command(
-    mut cmd: Command,
-    cmd_description: &str,
-    output: &mut Vec<u8>,
-    stderr: bool,
-) -> Result<bool> {
-    let (mut reader, writer) = os_pipe::pipe().with_context(|| {
-        format!("Failed to create a pipe to run the command `{cmd_description}``")
-    })?;
-
-    let (stdout, stderr) = if stderr {
-        (
-            Stdio::from(writer.try_clone().with_context(|| {
-                format!("Failed to clone the pipe writer for the command `{cmd_description}`")
-            })?),
-            Stdio::from(writer),
-        )
-    } else {
-        (Stdio::from(writer), Stdio::null())
-    };
-
-    let mut handle = cmd
-        .stdout(stdout)
-        .stderr(stderr)
-        .spawn()
-        .with_context(|| format!("Failed to run the command `{cmd_description}`"))?;
-
-    // Prevent pipe deadlock.
-    drop(cmd);
-
-    reader
-        .read_to_end(output)
-        .with_context(|| format!("Failed to read the output of the command `{cmd_description}`"))?;
-
-    output.push(b'\n');
-
-    handle
-        .wait()
-        .with_context(|| format!("Failed to wait on the command `{cmd_description}` to exit"))
-        .map(|status| status.success())
-}
-
 pub struct Exercise {
     pub dir: Option<&'static str>,
     // Exercise's unique name
@@ -66,11 +30,16 @@ pub struct Exercise {
 }
 
 impl Exercise {
-    fn run_bin(&self, output: &mut Vec<u8>) -> Result<bool> {
+    fn run_bin(&self, output: &mut Vec<u8>, target_dir: &Path) -> Result<bool> {
         writeln!(output, "{}", "Output".underlined())?;
 
-        let bin_path = format!("target/debug/{}", self.name);
-        let success = run_command(Command::new(&bin_path), &bin_path, output, true)?;
+        let mut bin_path =
+            PathBuf::with_capacity(target_dir.as_os_str().len() + 7 + self.name.len());
+        bin_path.push(target_dir);
+        bin_path.push("debug");
+        bin_path.push(self.name);
+
+        let success = run_cmd(Command::new(&bin_path), &bin_path.to_string_lossy(), output)?;
 
         if !success {
             writeln!(
@@ -85,43 +54,23 @@ impl Exercise {
         Ok(success)
     }
 
-    fn cargo_cmd(
-        &self,
-        command: &str,
-        args: &[&str],
-        cmd_description: &str,
-        output: &mut Vec<u8>,
-        dev: bool,
-        stderr: bool,
-    ) -> Result<bool> {
-        let mut cmd = Command::new("cargo");
-        cmd.arg(command);
-
-        // A hack to make `cargo run` work when developing Rustlings.
-        if dev {
-            cmd.arg("--manifest-path")
-                .arg("dev/Cargo.toml")
-                .arg("--target-dir")
-                .arg("target");
-        }
-
-        cmd.arg("--color")
-            .arg("always")
-            .arg("-q")
-            .arg("--bin")
-            .arg(self.name)
-            .args(args);
-
-        run_command(cmd, cmd_description, output, stderr)
-    }
-
-    pub fn run(&self, output: &mut Vec<u8>) -> Result<bool> {
+    pub fn run(&self, output: &mut Vec<u8>, target_dir: &Path) -> Result<bool> {
         output.clear();
 
         // Developing the official Rustlings.
         let dev = DEBUG_PROFILE && in_official_repo();
 
-        let build_success = self.cargo_cmd("build", &[], "cargo build …", output, dev, true)?;
+        let build_success = CargoCmd {
+            subcommand: "build",
+            args: &[],
+            exercise_name: self.name,
+            description: "cargo build …",
+            hide_warnings: false,
+            target_dir,
+            output,
+            dev,
+        }
+        .run()?;
         if !build_success {
             return Ok(false);
         }
@@ -134,19 +83,28 @@ impl Exercise {
         } else {
             &["--profile", "test"]
         };
-        let clippy_success =
-            self.cargo_cmd("clippy", clippy_args, "cargo clippy …", output, dev, true)?;
+        let clippy_success = CargoCmd {
+            subcommand: "clippy",
+            args: clippy_args,
+            exercise_name: self.name,
+            description: "cargo clippy …",
+            hide_warnings: false,
+            target_dir,
+            output,
+            dev,
+        }
+        .run()?;
         if !clippy_success {
             return Ok(false);
         }
 
         if !self.test {
-            return self.run_bin(output);
+            return self.run_bin(output, target_dir);
         }
 
-        let test_success = self.cargo_cmd(
-            "test",
-            &[
+        let test_success = CargoCmd {
+            subcommand: "test",
+            args: &[
                 "--",
                 "--color",
                 "always",
@@ -154,14 +112,17 @@ impl Exercise {
                 "--format",
                 "pretty",
             ],
-            "cargo test …",
+            exercise_name: self.name,
+            description: "cargo test …",
+            // Hide warnings because they are shown by Clippy.
+            hide_warnings: true,
+            target_dir,
             output,
             dev,
-            // Hide warnings because they are shown by Clippy.
-            false,
-        )?;
+        }
+        .run()?;
 
-        let run_success = self.run_bin(output)?;
+        let run_success = self.run_bin(output, target_dir)?;
 
         Ok(test_success && run_success)
     }
diff --git a/src/main.rs b/src/main.rs
index 7a142fd..b03aa52 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -5,16 +5,18 @@ use crossterm::{
     terminal::{Clear, ClearType},
     ExecutableCommand,
 };
+use serde::Deserialize;
 use std::{
     io::{self, BufRead, Write},
-    path::Path,
-    process::exit,
+    path::{Path, PathBuf},
+    process::{exit, Command, Stdio},
 };
 
 use self::{app_state::AppState, dev::DevCommands, info_file::InfoFile, watch::WatchExit};
 
 mod app_state;
 mod cargo_toml;
+mod cmd;
 mod dev;
 mod embedded;
 mod exercise;
@@ -75,6 +77,11 @@ enum Subcommands {
     Dev(DevCommands),
 }
 
+#[derive(Deserialize)]
+struct CargoMetadata {
+    target_directory: PathBuf,
+}
+
 fn in_official_repo() -> bool {
     Path::new("dev/rustlings-repo.txt").exists()
 }
@@ -86,7 +93,20 @@ fn main() -> Result<()> {
         bail!("{OLD_METHOD_ERR}");
     }
 
-    which::which("cargo").context(CARGO_NOT_FOUND_ERR)?;
+    let metadata_output = Command::new("cargo")
+        .arg("metadata")
+        .arg("-q")
+        .arg("--format-version")
+        .arg("1")
+        .arg("--no-deps")
+        .stdin(Stdio::null())
+        .stderr(Stdio::inherit())
+        .output()
+        .context(CARGO_METADATA_ERR)?
+        .stdout;
+    let target_dir = serde_json::de::from_slice::<CargoMetadata>(&metadata_output)
+        .context("Failed to read the field `target_directory` from the `cargo metadata` output")?
+        .target_directory;
 
     match args.command {
         Some(Subcommands::Init) => {
@@ -122,6 +142,7 @@ fn main() -> Result<()> {
     let (mut app_state, state_file_status) = AppState::new(
         info_file.exercises,
         info_file.final_message.unwrap_or_default(),
+        target_dir,
     );
 
     if let Some(welcome_message) = info_file.welcome_message {
@@ -198,7 +219,7 @@ The new method doesn't include cloning the Rustlings' repository.
 Please follow the instructions in the README:
 https://github.com/rust-lang/rustlings#getting-started";
 
-const CARGO_NOT_FOUND_ERR: &str = "Failed to find `cargo`.
+const CARGO_METADATA_ERR: &str = "Failed to run the command `cargo metadata …`
 Did you already install Rust?
 Try running `cargo --version` to diagnose the problem.";
 
diff --git a/src/run.rs b/src/run.rs
index cbc9ad7..9b5ddd3 100644
--- a/src/run.rs
+++ b/src/run.rs
@@ -11,7 +11,7 @@ use crate::{
 pub fn run(app_state: &mut AppState) -> Result<()> {
     let exercise = app_state.current_exercise();
     let mut output = Vec::with_capacity(OUTPUT_CAPACITY);
-    let success = exercise.run(&mut output)?;
+    let success = exercise.run(&mut output, app_state.target_dir())?;
 
     let mut stdout = io::stdout().lock();
     stdout.write_all(&output)?;
diff --git a/src/watch/state.rs b/src/watch/state.rs
index 40c01bf..82b745a 100644
--- a/src/watch/state.rs
+++ b/src/watch/state.rs
@@ -50,7 +50,10 @@ impl<'a> WatchState<'a> {
     pub fn run_current_exercise(&mut self) -> Result<()> {
         self.show_hint = false;
 
-        let success = self.app_state.current_exercise().run(&mut self.output)?;
+        let success = self
+            .app_state
+            .current_exercise()
+            .run(&mut self.output, self.app_state.target_dir())?;
         if success {
             self.done_status =
                 if let Some(solution_path) = self.app_state.current_solution_path()? {