use regex::Regex; use serde::Deserialize; use std::fmt::{self, Display, Formatter}; use std::fs::{remove_file, File}; use std::io::Read; use std::path::PathBuf; use std::process::{self, Command}; const RUSTC_COLOR_ARGS: &[&str] = &["--color", "always"]; const I_AM_DONE_REGEX: &str = r"(?m)^\s*///?\s*I\s+AM\s+NOT\s+DONE"; const CONTEXT: usize = 2; fn temp_file() -> String { format!("./temp_{}", process::id()) } #[derive(Deserialize, Copy, Clone)] #[serde(rename_all = "lowercase")] pub enum Mode { Compile, Test, } #[derive(Deserialize)] pub struct ExerciseList { pub exercises: Vec, } #[derive(Deserialize)] pub struct Exercise { pub name: String, pub path: PathBuf, pub mode: Mode, pub hint: String, } #[derive(PartialEq, Debug)] pub enum State { Done, Pending(Vec), } #[derive(PartialEq, Debug)] pub struct ContextLine { pub line: String, pub number: usize, pub important: bool, } pub struct CompiledExercise<'a> { exercise: &'a Exercise, _handle: FileHandle, } impl<'a> CompiledExercise<'a> { pub fn run(&self) -> Result { self.exercise.run() } } #[derive(Debug)] pub struct ExerciseOutput { pub stdout: String, pub stderr: String, } struct FileHandle; impl Drop for FileHandle { fn drop(&mut self) { clean(); } } impl Exercise { pub fn compile(&self) -> Result { let cmd = match self.mode { Mode::Compile => Command::new("rustc") .args(&[self.path.to_str().unwrap(), "-o", &temp_file()]) .args(RUSTC_COLOR_ARGS) .output(), Mode::Test => Command::new("rustc") .args(&["--test", self.path.to_str().unwrap(), "-o", &temp_file()]) .args(RUSTC_COLOR_ARGS) .output(), } .expect("Failed to run 'compile' command."); if cmd.status.success() { Ok(CompiledExercise { exercise: &self, _handle: FileHandle, }) } else { clean(); Err(ExerciseOutput { stdout: String::from_utf8_lossy(&cmd.stdout).to_string(), stderr: String::from_utf8_lossy(&cmd.stderr).to_string(), }) } } fn run(&self) -> Result { let cmd = Command::new(&temp_file()) .output() .expect("Failed to run 'run' command"); let output = ExerciseOutput { stdout: String::from_utf8_lossy(&cmd.stdout).to_string(), stderr: String::from_utf8_lossy(&cmd.stderr).to_string(), }; if cmd.status.success() { Ok(output) } else { Err(output) } } pub fn state(&self) -> State { let mut source_file = File::open(&self.path).expect("We were unable to open the exercise file!"); let source = { let mut s = String::new(); source_file .read_to_string(&mut s) .expect("We were unable to read the exercise file!"); s }; let re = Regex::new(I_AM_DONE_REGEX).unwrap(); if !re.is_match(&source) { return State::Done; } let matched_line_index = source .lines() .enumerate() .filter_map(|(i, line)| if re.is_match(line) { Some(i) } else { None }) .next() .expect("This should not happen at all"); let min_line = ((matched_line_index as i32) - (CONTEXT as i32)).max(0) as usize; let max_line = matched_line_index + CONTEXT; let context = source .lines() .enumerate() .filter(|&(i, _)| i >= min_line && i <= max_line) .map(|(i, line)| ContextLine { line: line.to_string(), number: i + 1, important: i == matched_line_index, }) .collect(); State::Pending(context) } } impl Display for Exercise { fn fmt(&self, f: &mut Formatter) -> fmt::Result { write!(f, "{}", self.path.to_str().unwrap()) } } fn clean() { let _ignored = remove_file(&temp_file()); } #[cfg(test)] mod test { use super::*; use std::path::Path; #[test] fn test_clean() { File::create(&temp_file()).unwrap(); let exercise = Exercise { name: String::from("example"), path: PathBuf::from("tests/fixture/state/pending_exercise.rs"), mode: Mode::Compile, hint: String::from(""), }; let compiled = exercise.compile().unwrap(); drop(compiled); assert!(!Path::new(&temp_file()).exists()); } #[test] fn test_pending_state() { let exercise = Exercise { name: "pending_exercise".into(), path: PathBuf::from("tests/fixture/state/pending_exercise.rs"), mode: Mode::Compile, hint: String::new(), }; let state = exercise.state(); let expected = vec![ ContextLine { line: "// fake_exercise".to_string(), number: 1, important: false, }, ContextLine { line: "".to_string(), number: 2, important: false, }, ContextLine { line: "// I AM NOT DONE".to_string(), number: 3, important: true, }, ContextLine { line: "".to_string(), number: 4, important: false, }, ContextLine { line: "fn main() {".to_string(), number: 5, important: false, }, ]; assert_eq!(state, State::Pending(expected)); } #[test] fn test_finished_exercise() { let exercise = Exercise { name: "finished_exercise".into(), path: PathBuf::from("tests/fixture/state/finished_exercise.rs"), mode: Mode::Compile, hint: String::new(), }; assert_eq!(exercise.state(), State::Done); } }