1 files changed, 50 insertions, 0 deletions
diff --git a/src/dev/update.rs b/src/dev/update.rs
new file mode 100644
index 0000000..66efe3d
--- /dev/null
+++ b/src/dev/update.rs
@@ -0,0 +1,50 @@
+use anyhow::{Context, Result};
+use std::fs;
+
+use crate::{
+    cargo_toml::updated_cargo_toml,
+    info_file::{ExerciseInfo, InfoFile},
+    DEBUG_PROFILE,
+};
+
+// Update the `Cargo.toml` file.
+fn update_cargo_toml(
+    exercise_infos: &[ExerciseInfo],
+    current_cargo_toml: &str,
+    exercise_path_prefix: &[u8],
+    cargo_toml_path: &str,
+) -> Result<()> {
+    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()?;
+
+    // A hack to make `cargo run -- dev update` work when developing Rustlings.
+    if DEBUG_PROFILE {
+        update_cargo_toml(
+            &info_file.exercises,
+            include_str!("../../dev-Cargo.toml"),
+            b"../",
+            "dev/Cargo.toml",
+        )
+        .context("Failed to update the file `dev/Cargo.toml`")?;
+
+        println!("Updated `dev/Cargo.toml`");
+    } else {
+        let current_cargo_toml =
+            fs::read_to_string("Cargo.toml").context("Failed to read the file `Cargo.toml`")?;
+        update_cargo_toml(&info_file.exercises, &current_cargo_toml, b"", "Cargo.toml")
+            .context("Failed to update the file `Cargo.toml`")?;
+
+        println!("Updated `Cargo.toml`");
+    }
+
+    Ok(())
+}