repo_description: :crab: Small exercises to get you used to reading and writing Rust code!
repo_topics: beginner-friendly exercises rust rustlings
code: use anyhow::{Context, Result};
  use std::fs;
  
  use crate::{
      cargo_toml::updated_cargo_toml,
      info_file::{ExerciseInfo, InfoFile},
  };
  
  // Update the `Cargo.toml` file.
  fn update_cargo_toml(
      exercise_infos: &[ExerciseInfo],
      cargo_toml_path: &str,
      exercise_path_prefix: &[u8],
  ) -> Result<()> {
      let current_cargo_toml = fs::read_to_string(cargo_toml_path)
          .with_context(|| format!("Failed to read the file `{cargo_toml_path}`"))?;
  
      let updated_cargo_toml =
          updated_cargo_toml(exercise_infos, &current_cargo_toml, exercise_path_prefix)?;
  
      fs::write(cargo_toml_path, updated_cargo_toml)
          .context("Failed to write the `Cargo.toml` file")?;
  
      Ok(())
  }
  
  pub fn update() -> Result<()> {
      let info_file = InfoFile::parse()?;
  
      if cfg!(debug_assertions) {
          // A hack to make `cargo dev update` work when developing Rustlings.
          update_cargo_toml(&info_file.exercises, "dev/Cargo.toml", b"../")
              .context("Failed to update the file `dev/Cargo.toml`")?;
  
          println!("Updated `dev/Cargo.toml`");
      } else {
          update_cargo_toml(&info_file.exercises, "Cargo.toml", &[])
              .context("Failed to update the file `Cargo.toml`")?;
  
          println!("Updated `Cargo.toml`");
      }
  
      Ok(())
  }
  