Merge branch 'master' into refactor-hints

4 files changed, 165 insertions, 12 deletions

diff --git a/src/exercise.rs b/src/exercise.rs
index 0e8a199..be59284 100644
--- a/src/exercise.rs
+++ b/src/exercise.rs
@@ -1,16 +1,20 @@
+use regex::Regex;
 use serde::Deserialize;
 use std::fmt::{self, Display, Formatter};
-use std::fs::remove_file;
+use std::fs::{remove_file, File};
+use std::io::Read;
 use std::path::PathBuf;
 use std::process::{self, Command, Output};
 
 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)]
+#[derive(Deserialize, Copy, Clone)]
 #[serde(rename_all = "lowercase")]
 pub enum Mode {
     Compile,
@@ -30,6 +34,19 @@ pub struct Exercise {
     pub hint: String,
 }
 
+#[derive(PartialEq, Debug)]
+pub enum State {
+    Done,
+    Pending(Vec<ContextLine>),
+}
+
+#[derive(PartialEq, Debug)]
+pub struct ContextLine {
+    pub line: String,
+    pub number: usize,
+    pub important: bool,
+}
+
 impl Exercise {
     pub fn compile(&self) -> Output {
         match self.mode {
@@ -54,6 +71,48 @@ impl Exercise {
     pub fn clean(&self) {
         let _ignored = remove_file(&temp_file());
     }
+
+    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 {
@@ -65,7 +124,6 @@ impl Display for Exercise {
 #[cfg(test)]
 mod test {
     use super::*;
-    use std::fs::File;
     use std::path::Path;
 
     #[test]
@@ -80,4 +138,53 @@ mod test {
         exercise.clean();
         assert!(!Path::new(&temp_file()).exists());
     }
+
+    #[test]
+    fn test_pending_state() {
+        let exercise = Exercise {
+            path: PathBuf::from("tests/fixture/state/pending_exercise.rs"),
+            mode: Mode::Compile,
+        };
+
+        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 {
+            path: PathBuf::from("tests/fixture/state/finished_exercise.rs"),
+            mode: Mode::Compile,
+        };
+
+        assert_eq!(exercise.state(), State::Done);
+    }
 }
diff --git a/src/main.rs b/src/main.rs
index 875f767..5a4af53 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -127,11 +127,11 @@ fn watch(exercises: &[Exercise]) -> notify::Result<()> {
                 DebouncedEvent::Create(b) | DebouncedEvent::Chmod(b) | DebouncedEvent::Write(b) => {
                     if b.extension() == Some(OsStr::new("rs")) && b.exists() {
                         let filepath = b.as_path().canonicalize().unwrap();
-                        let exercise = exercises
+                        let pending_exercises = exercises
                             .iter()
                             .skip_while(|e| !filepath.ends_with(&e.path));
                         clear_screen();
-                        let _ignored = verify(exercise);
+                        let _ignored = verify(pending_exercises);
                     }
                 }
                 _ => {}
diff --git a/src/run.rs b/src/run.rs
index 1484351..1f777ec 100644
--- a/src/run.rs
+++ b/src/run.rs
@@ -5,7 +5,9 @@ use indicatif::ProgressBar;
 
 pub fn run(exercise: &Exercise) -> Result<(), ()> {
     match exercise.mode {
-        Mode::Test => test(exercise)?,
+        Mode::Test => {
+            test(exercise)?;
+        }
         Mode::Compile => compile_and_run(exercise)?,
     }
     Ok(())
diff --git a/src/verify.rs b/src/verify.rs
index d066afa..020102e 100644
--- a/src/verify.rs
+++ b/src/verify.rs
@@ -1,18 +1,21 @@
-use crate::exercise::{Exercise, Mode};
+use crate::exercise::{ContextLine, Exercise, Mode, State};
 use console::{style, Emoji};
 use indicatif::ProgressBar;
 
 pub fn verify<'a>(start_at: impl IntoIterator<Item = &'a Exercise>) -> Result<(), ()> {
     for exercise in start_at {
-        match exercise.mode {
+        let is_done = match exercise.mode {
             Mode::Test => test(&exercise)?,
             Mode::Compile => compile_only(&exercise)?,
+        };
+        if !is_done {
+            return Err(());
         }
     }
     Ok(())
 }
 
-fn compile_only(exercise: &Exercise) -> Result<(), ()> {
+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);
@@ -22,7 +25,12 @@ fn compile_only(exercise: &Exercise) -> Result<(), ()> {
         let formatstr = format!("{} Successfully compiled {}!", Emoji("✅", "✓"), exercise);
         println!("{}", style(formatstr).green());
         exercise.clean();
-        Ok(())
+        if let State::Pending(context) = exercise.state() {
+            print_everything_looks_good(exercise.mode, context);
+            Ok(false)
+        } else {
+            Ok(true)
+        }
     } else {
         let formatstr = format!(
             "{} Compilation of {} failed! Compiler error message:\n",
@@ -36,7 +44,7 @@ fn compile_only(exercise: &Exercise) -> Result<(), ()> {
     }
 }
 
-pub fn test(exercise: &Exercise) -> Result<(), ()> {
+pub fn test(exercise: &Exercise) -> Result<bool, ()> {
     let progress_bar = ProgressBar::new_spinner();
     progress_bar.set_message(format!("Testing {}...", exercise).as_str());
     progress_bar.enable_steady_tick(100);
@@ -52,7 +60,12 @@ pub fn test(exercise: &Exercise) -> Result<(), ()> {
             let formatstr = format!("{} Successfully tested {}!", Emoji("✅", "✓"), exercise);
             println!("{}", style(formatstr).green());
             exercise.clean();
-            Ok(())
+            if let State::Pending(context) = exercise.state() {
+                print_everything_looks_good(exercise.mode, context);
+                Ok(false)
+            } else {
+                Ok(true)
+            }
         } else {
             let formatstr = format!(
                 "{} Testing of {} failed! Please try again. Here's the output:",
@@ -77,3 +90,34 @@ pub fn test(exercise: &Exercise) -> Result<(), ()> {
         Err(())
     }
 }
+
+fn print_everything_looks_good(mode: Mode, context: Vec<ContextLine>) {
+    let success_msg = match mode {
+        Mode::Compile => "The code is compiling!",
+        Mode::Test => "The code is compiling, and the tests pass!",
+    };
+
+    println!("");
+    println!("🎉 🎉  {} 🎉 🎉", success_msg);
+    println!("");
+    println!("You can keep working on this exercise,");
+    println!(
+        "or jump into the next one by removing the {} comment:",
+        style("`I AM NOT DONE`").bold()
+    );
+    println!("");
+    for context_line in context {
+        let formatted_line = if context_line.important {
+            format!("{}", style(context_line.line).bold())
+        } else {
+            format!("{}", context_line.line)
+        };
+
+        println!(
+            "{:>2} {}  {}",
+            style(context_line.number).blue().bold(),
+            style("|").blue(),
+            formatted_line
+        );
+    }
+}