feat: add support for exercises that depend on crates

exercises/crates/mockall/mocks1/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "mocks1"
+version = "0.0.1"
+edition = "2021"
+
+[dependencies]
+mockall = "0.11.4"
+
+[[bin]]
+name = "mocks1"
+path = "mocks1.rs"

exercises/crates/mockall/mocks1/mocks1.rs

@@ -0,0 +1,45 @@
+// mocks1.rs
+//
+// Mockall is a powerful mock object library for Rust. It provides tools to create 
+// mock versions of almost any trait or struct. They can be used in unit tests as 
+// a stand-in for the real object.
+// 
+// These tests each contain an expectation that defines some behaviour we expect on
+// calls to the function "foo". Add the "foo" function call and get the tests to pass 
+//
+// I AM NOT DONE
+
+use mockall::*;
+use mockall::predicate::*;
+
+#[automock]
+trait MyTrait {
+    fn foo(&self) -> bool;
+}
+
+fn follow_path_from_trait(x: &dyn MyTrait) -> String {
+    if ??? {
+        String::from("Followed path A")
+    }
+    else {
+        String::from("Followed path B")
+    }
+}
+
+#[test]
+fn can_follow_path_a() {
+    let mut mock = MockMyTrait::new();
+    mock.expect_foo()
+        .times(1)
+        .returning(||true);
+    assert_eq!(follow_path_from_trait(&mock), "Followed path A");
+}
+
+#[test]
+fn can_follow_path_b() {    
+    let mut mock = MockMyTrait::new();
+    mock.expect_foo()
+        .times(1)
+        .returning(||false);
+    assert_eq!(follow_path_from_trait(&mock), "Followed path B");
+}

info.toml

@@ -1319,3 +1319,10 @@ path = "exercises/23_conversions/as_ref_mut.rs"
 mode = "test"
 hint = """
 Add `AsRef<str>` or `AsMut<u32>` as a trait bound to the functions."""
+
+[[exercises]]
+name = "mocks1"
+path = "exercises/crates/mockall/mocks1/Cargo.toml"
+mode = "cratetest"
+hint = """
+x.foo() needs to be called in the if conditional to get the tests to pass."""

src/exercise.rs

@@ -1,5 +1,6 @@
 use regex::Regex;
 use serde::Deserialize;
+use serde_json::Value;
 use std::env;
 use std::fmt::{self, Display, Formatter};
 use std::fs::{self, remove_file, File};
@@ -35,6 +36,10 @@ pub enum Mode {
     Test,
     // Indicates that the exercise should be linted with clippy
     Clippy,
+    // Indicates that the exercise should be compiled as a binary and requires a crate
+    CrateCompile,
+    // Indicates that the exercise should be compiled as a test harness and requires a crate
+    CrateTest,
 }
 
 #[derive(Deserialize)]
@@ -50,7 +55,7 @@ pub struct Exercise {
     pub name: String,
     // The path to the file containing the exercise's source code
     pub path: PathBuf,
-    // The mode of the exercise (Test, Compile, or Clippy)
+    // The mode of the exercise (Test, Compile, Clippy, CrateCompile or CrateTest
     pub mode: Mode,
     // The hint text associated with the exercise
     pub hint: String,
@@ -81,12 +86,13 @@ pub struct ContextLine {
 pub struct CompiledExercise<'a> {
     exercise: &'a Exercise,
     _handle: FileHandle,
+    pub stdout: String,
 }
 
 impl<'a> CompiledExercise<'a> {
     // Run the compiled exercise
     pub fn run(&self) -> Result<ExerciseOutput, ExerciseOutput> {
-        self.exercise.run()
+        self.exercise.run(&self.stdout)
     }
 }
 
@@ -164,6 +170,19 @@ path = "{}.rs""#,
                     .args(RUSTC_COLOR_ARGS)
                     .args(["--", "-D", "warnings", "-D", "clippy::float_cmp"])
                     .output()
+            },
+            Mode::CrateCompile => {
+                Command::new("cargo")
+                    .args(["build", "--manifest-path", self.path.to_str().unwrap(), "--target-dir", &temp_file()])
+                    .output()
+            },
+            Mode::CrateTest => {
+                Command::new("cargo")
+                    .args(["test", "--no-run"])
+                    .args(["--manifest-path", self.path.to_str().unwrap()])
+                    .args(["--target-dir", &temp_file()])
+                    .args(["--message-format", "json-render-diagnostics"])
+                    .output()
             }
         }
         .expect("Failed to run 'compile' command.");
@@ -172,8 +191,10 @@ path = "{}.rs""#,
             Ok(CompiledExercise {
                 exercise: self,
                 _handle: FileHandle,
+                stdout: String::from_utf8_lossy(&cmd.stdout).to_string(),
             })
         } else {
+            self.cleanup_temporary_dirs_by_mode();
             clean();
             Err(ExerciseOutput {
                 stdout: String::from_utf8_lossy(&cmd.stdout).to_string(),
@@ -182,26 +203,72 @@ path = "{}.rs""#,
         }
     }
 
-    fn run(&self) -> Result<ExerciseOutput, ExerciseOutput> {
+    fn get_crate_test_filename(&self, stdout: &str) -> Result<String, ()> {
+        let json_objects = stdout.split("\n");
+        for json_object in json_objects {
+            let parsed_json: Value = serde_json::from_str(json_object).unwrap();
+            if parsed_json["target"]["kind"][0] == "bin" {
+                return Ok(String::from(parsed_json["filenames"][0].as_str().unwrap()));
+            }
+        }
+        Err(())
+    }
+
+    fn get_compiled_filename_by_mode(&self, compilation_stdout: &str) -> String {
+        match self.mode {
+            Mode::CrateCompile => temp_file() + "/debug/" + &self.name,
+            Mode::CrateTest => {
+                let get_filename_result = self.get_crate_test_filename(&compilation_stdout);
+                match get_filename_result {
+                    Ok(filename) => filename,
+                    Err(()) => panic!("Failed to get crate test filename")
+                }
+            },
+            _ => temp_file()
+        }
+    }
+
+    fn cleanup_temporary_dirs_by_mode(&self) {
+        match self.mode {
+            Mode::CrateCompile | Mode::CrateTest => fs::remove_dir_all(temp_file())
+                .expect("Failed to cleanup temp build dir"),
+            _ => ()
+        }
+    }
+
+    fn run(&self, compilation_stdout: &str) -> Result<ExerciseOutput, ExerciseOutput> {
         let arg = match self.mode {
-            Mode::Test => "--show-output",
+            Mode::Test | Mode::CrateTest => "--show-output",
             _ => "",
         };
-        let cmd = Command::new(temp_file())
-            .arg(arg)
-            .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(),
-        };
+        let filename = self.get_compiled_filename_by_mode(compilation_stdout);
 
-        if cmd.status.success() {
-            Ok(output)
-        } else {
-            Err(output)
-        }
+        let command_output = Command::new(filename)
+            .arg(arg)
+            .output();
+        let result = match command_output {
+            Ok(cmd) => {
+                let output = ExerciseOutput {
+                    stdout: String::from_utf8_lossy(&cmd.stdout).to_string(),
+                    stderr: String::from_utf8_lossy(&cmd.stderr).to_string(),
+                };
+
+                self.cleanup_temporary_dirs_by_mode();
+
+                if cmd.status.success() {
+                    Ok(output)
+                } else {
+                    Err(output)
+                }
+            },
+            Err(msg) => {
+                self.cleanup_temporary_dirs_by_mode();
+                println!("Error: {}", msg);
+                panic!("Failed to run 'run' command");
+            }
+        };
+        result
     }
 
     pub fn state(&self) -> State {

src/run.rs

@@ -11,8 +11,8 @@ use indicatif::ProgressBar;
 // the output from the test harnesses (if the mode of the exercise is test)
 pub fn run(exercise: &Exercise, verbose: bool) -> Result<(), ()> {
     match exercise.mode {
-        Mode::Test => test(exercise, verbose)?,
-        Mode::Compile => compile_and_run(exercise)?,
+        Mode::Test | Mode::CrateTest => test(exercise, verbose)?,
+        Mode::Compile | Mode::CrateCompile => compile_and_run(exercise)?,
         Mode::Clippy => compile_and_run(exercise)?,
     }
     Ok(())

src/verify.rs

@@ -28,8 +28,8 @@ pub fn verify<'a>(
 
     for exercise in exercises {
         let compile_result = match exercise.mode {
-            Mode::Test => compile_and_test(exercise, RunMode::Interactive, verbose, success_hints),
-            Mode::Compile => compile_and_run_interactively(exercise, success_hints),
+            Mode::Test | Mode::CrateTest => compile_and_test(exercise, RunMode::Interactive, verbose, success_hints),
+            Mode::Compile | Mode::CrateCompile => compile_and_run_interactively(exercise, success_hints),
             Mode::Clippy => compile_only(exercise, success_hints),
         };
         if !compile_result.unwrap_or(false) {
@@ -164,8 +164,8 @@ fn prompt_for_completion(
         State::Pending(context) => context,
     };
     match exercise.mode {
-        Mode::Compile => success!("Successfully ran {}!", exercise),
-        Mode::Test => success!("Successfully tested {}!", exercise),
+        Mode::Compile | Mode::CrateCompile => success!("Successfully ran {}!", exercise),
+        Mode::Test | Mode::CrateTest => success!("Successfully tested {}!", exercise),
         Mode::Clippy => success!("Successfully compiled {}!", exercise),
     }
 
@@ -178,8 +178,8 @@ fn prompt_for_completion(
     };
 
     let success_msg = match exercise.mode {
-        Mode::Compile => "The code is compiling!",
-        Mode::Test => "The code is compiling, and the tests pass!",
+        Mode::Compile | Mode::CrateCompile => "The code is compiling!",
+        Mode::Test | Mode::CrateTest => "The code is compiling, and the tests pass!",
         Mode::Clippy => clippy_success_msg,
     };
     println!();