Auto merge of #271 - jrvidal:refactor, r=fmoko

refactor: exercise evaluation

After working a bit on #270, I realized that it'd be useful to first perform a minor refactor of exercise evaluation.

* Now we have standard methods to compile + execute that return `Result`s.
* Success/failure messages are standardized.

src/exercise.rs

@@ -4,7 +4,7 @@ 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, Output};
+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";
@@ -47,9 +47,34 @@ pub struct ContextLine {
     pub important: bool,
 }
 
+pub struct CompiledExercise<'a> {
+    exercise: &'a Exercise,
+    _handle: FileHandle,
+}
+
+impl<'a> CompiledExercise<'a> {
+    pub fn run(&self) -> Result<ExerciseOutput, ExerciseOutput> {
+        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) -> Output {
-        match self.mode {
+    pub fn compile(&self) -> Result<CompiledExercise, ExerciseOutput> {
+        let cmd = match self.mode {
             Mode::Compile => Command::new("rustc")
                 .args(&[self.path.to_str().unwrap(), "-o", &temp_file()])
                 .args(RUSTC_COLOR_ARGS)
@@ -59,17 +84,37 @@ impl Exercise {
                 .args(RUSTC_COLOR_ARGS)
                 .output(),
         }
-        .expect("Failed to run 'compile' command.")
+        .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(),
+            })
+        }
     }
 
-    pub fn run(&self) -> Output {
-        Command::new(&temp_file())
+    fn run(&self) -> Result<ExerciseOutput, ExerciseOutput> {
+        let cmd = Command::new(&temp_file())
             .output()
-            .expect("Failed to run 'run' command")
-    }
+            .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(),
+        };
 
-    pub fn clean(&self) {
-        let _ignored = remove_file(&temp_file());
+        if cmd.status.success() {
+            Ok(output)
+        } else {
+            Err(output)
+        }
     }
 
     pub fn state(&self) -> State {
@@ -121,6 +166,10 @@ impl Display for Exercise {
     }
 }
 
+fn clean() {
+    let _ignored = remove_file(&temp_file());
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
@@ -131,11 +180,12 @@ mod test {
         File::create(&temp_file()).unwrap();
         let exercise = Exercise {
             name: String::from("example"),
-            path: PathBuf::from("example.rs"),
-            mode: Mode::Test,
+            path: PathBuf::from("tests/fixture/state/pending_exercise.rs"),
+            mode: Mode::Compile,
             hint: String::from(""),
         };
-        exercise.clean();
+        let compiled = exercise.compile().unwrap();
+        drop(compiled);
         assert!(!Path::new(&temp_file()).exists());
     }
 

src/main.rs

@@ -15,6 +15,9 @@ use std::sync::{Arc, Mutex};
 use std::thread;
 use std::time::Duration;
 
+#[macro_use]
+mod ui;
+
 mod exercise;
 mod run;
 mod verify;

src/run.rs

@@ -1,6 +1,5 @@
 use crate::exercise::{Exercise, Mode};
 use crate::verify::test;
-use console::{style, Emoji};
 use indicatif::ProgressBar;
 
 pub fn run(exercise: &Exercise) -> Result<(), ()> {
@@ -11,42 +10,41 @@ pub fn run(exercise: &Exercise) -> Result<(), ()> {
     Ok(())
 }
 
-pub fn compile_and_run(exercise: &Exercise) -> Result<(), ()> {
+fn compile_and_run(exercise: &Exercise) -> Result<(), ()> {
     let progress_bar = ProgressBar::new_spinner();
     progress_bar.set_message(format!("Compiling {}...", exercise).as_str());
     progress_bar.enable_steady_tick(100);
 
-    let compilecmd = exercise.compile();
+    let compilation_result = exercise.compile();
+    let compilation = match compilation_result {
+        Ok(compilation) => compilation,
+        Err(output) => {
+            progress_bar.finish_and_clear();
+            warn!(
+                "Compilation of {} failed!, Compiler error message:\n",
+                exercise
+            );
+            println!("{}", output.stderr);
+            return Err(());
+        }
+    };
+
     progress_bar.set_message(format!("Running {}...", exercise).as_str());
-    if compilecmd.status.success() {
-        let runcmd = exercise.run();
-        progress_bar.finish_and_clear();
+    let result = compilation.run();
+    progress_bar.finish_and_clear();
 
-        if runcmd.status.success() {
-            println!("{}", String::from_utf8_lossy(&runcmd.stdout));
-            let formatstr = format!("{} Successfully ran {}", Emoji("✅", "✓"), exercise);
-            println!("{}", style(formatstr).green());
-            exercise.clean();
+    match result {
+        Ok(output) => {
+            println!("{}", output.stdout);
+            success!("Successfully ran {}", exercise);
             Ok(())
-        } else {
-            println!("{}", String::from_utf8_lossy(&runcmd.stdout));
-            println!("{}", String::from_utf8_lossy(&runcmd.stderr));
+        }
+        Err(output) => {
+            println!("{}", output.stdout);
+            println!("{}", output.stderr);
 
-            let formatstr = format!("{} Ran {} with errors", Emoji("⚠️ ", "!"), exercise);
-            println!("{}", style(formatstr).red());
-            exercise.clean();
+            warn!("Ran {} with errors", exercise);
             Err(())
         }
-    } else {
-        progress_bar.finish_and_clear();
-        let formatstr = format!(
-            "{} Compilation of {} failed! Compiler error message:\n",
-            Emoji("⚠️ ", "!"),
-            exercise
-        );
-        println!("{}", style(formatstr).red());
-        println!("{}", String::from_utf8_lossy(&compilecmd.stderr));
-        exercise.clean();
-        Err(())
     }
 }

src/ui.rs

@@ -0,0 +1,23 @@
+macro_rules! warn {
+    ($fmt:literal, $ex:expr) => {{
+        use console::{style, Emoji};
+        let formatstr = format!($fmt, $ex);
+        println!(
+            "{} {}",
+            style(Emoji("⚠️ ", "!")).red(),
+            style(formatstr).red()
+        );
+    }};
+}
+
+macro_rules! success {
+    ($fmt:literal, $ex:expr) => {{
+        use console::{style, Emoji};
+        let formatstr = format!($fmt, $ex);
+        println!(
+            "{} {}",
+            style(Emoji("✅", "✓")).green(),
+            style(formatstr).green()
+        );
+    }};
+}

src/verify.rs

@@ -1,11 +1,11 @@
 use crate::exercise::{Exercise, Mode, State};
-use console::{style, Emoji};
+use console::style;
 use indicatif::ProgressBar;
 
 pub fn verify<'a>(start_at: impl IntoIterator<Item = &'a Exercise>) -> Result<(), &'a Exercise> {
     for exercise in start_at {
         let compile_result = match exercise.mode {
-            Mode::Test => compile_and_test_interactively(&exercise),
+            Mode::Test => compile_and_test(&exercise, RunMode::Interactive),
             Mode::Compile => compile_only(&exercise),
         };
         if !compile_result.unwrap_or(false) {
@@ -15,78 +15,78 @@ pub fn verify<'a>(start_at: impl IntoIterator<Item = &'a Exercise>) -> Result<()
     Ok(())
 }
 
+enum RunMode {
+    Interactive,
+    NonInteractive,
+}
+
 pub fn test(exercise: &Exercise) -> Result<(), ()> {
-    compile_and_test(exercise, true)?;
+    compile_and_test(exercise, RunMode::NonInteractive)?;
     Ok(())
 }
 
 fn compile_only(exercise: &Exercise) -> Result<bool, ()> {
     let progress_bar = ProgressBar::new_spinner();
     progress_bar.set_message(format!("Compiling {}...", exercise).as_str());
     progress_bar.enable_steady_tick(100);
-    let compile_output = exercise.compile();
+    let compilation_result = exercise.compile();
     progress_bar.finish_and_clear();
-    if compile_output.status.success() {
-        let formatstr = format!("{} Successfully compiled {}!", Emoji("✅", "✓"), exercise);
-        println!("{}", style(formatstr).green());
-        exercise.clean();
-        Ok(prompt_for_completion(&exercise))
-    } else {
-        let formatstr = format!(
-            "{} Compilation of {} failed! Compiler error message:\n",
-            Emoji("⚠️ ", "!"),
-            exercise
-        );
-        println!("{}", style(formatstr).red());
-        println!("{}", String::from_utf8_lossy(&compile_output.stderr));
-        exercise.clean();
-        Err(())
-    }
-}
 
-fn compile_and_test_interactively(exercise: &Exercise) -> Result<bool, ()> {
-    compile_and_test(exercise, false)
+    match compilation_result {
+        Ok(_) => {
+            success!("Successfully compiled {}!", exercise);
+            Ok(prompt_for_completion(&exercise))
+        }
+        Err(output) => {
+            warn!(
+                "Compilation of {} failed! Compiler error message:\n",
+                exercise
+            );
+            println!("{}", output.stderr);
+            Err(())
+        }
+    }
 }
 
-fn compile_and_test(exercise: &Exercise, skip_prompt: bool) -> Result<bool, ()> {
+fn compile_and_test(exercise: &Exercise, run_mode: RunMode) -> Result<bool, ()> {
     let progress_bar = ProgressBar::new_spinner();
     progress_bar.set_message(format!("Testing {}...", exercise).as_str());
     progress_bar.enable_steady_tick(100);
 
-    let compile_output = exercise.compile();
-    if compile_output.status.success() {
-        progress_bar.set_message(format!("Running {}...", exercise).as_str());
+    let compilation_result = exercise.compile();
+
+    let compilation = match compilation_result {
+        Ok(compilation) => compilation,
+        Err(output) => {
+            progress_bar.finish_and_clear();
+            warn!(
+                "Compiling of {} failed! Please try again. Here's the output:",
+                exercise
+            );
+            println!("{}", output.stderr);
+            return Err(());
+        }
+    };
 
-        let runcmd = exercise.run();
-        progress_bar.finish_and_clear();
+    let result = compilation.run();
+    progress_bar.finish_and_clear();
 
-        if runcmd.status.success() {
-            let formatstr = format!("{} Successfully tested {}!", Emoji("✅", "✓"), exercise);
-            println!("{}", style(formatstr).green());
-            exercise.clean();
-            Ok(skip_prompt || prompt_for_completion(exercise))
-        } else {
-            let formatstr = format!(
-                "{} Testing of {} failed! Please try again. Here's the output:",
-                Emoji("⚠️ ", "!"),
+    match result {
+        Ok(_) => {
+            if let RunMode::Interactive = run_mode {
+                Ok(prompt_for_completion(&exercise))
+            } else {
+                Ok(true)
+            }
+        }
+        Err(output) => {
+            warn!(
+                "Testing of {} failed! Please try again. Here's the output:",
                 exercise
             );
-            println!("{}", style(formatstr).red());
-            println!("{}", String::from_utf8_lossy(&runcmd.stdout));
-            exercise.clean();
+            println!("{}", output.stdout);
             Err(())
         }
-    } else {
-        progress_bar.finish_and_clear();
-        let formatstr = format!(
-            "{} Compiling of {} failed! Please try again. Here's the output:",
-            Emoji("⚠️ ", "!"),
-            exercise
-        );
-        println!("{}", style(formatstr).red());
-        println!("{}", String::from_utf8_lossy(&compile_output.stderr));
-        exercise.clean();
-        Err(())
     }
 }