Fix the generated Cargo.toml after rustlings init

src/dev/check.rs

@@ -7,6 +7,7 @@ use std::{
 };
 
 use crate::{
+    cargo_toml::{append_bins, bins_start_end_ind},
     info_file::{ExerciseInfo, InfoFile},
     CURRENT_FORMAT_VERSION, DEBUG_PROFILE,
 };
@@ -136,41 +137,6 @@ fn check_exercises(info_file: &InfoFile) -> Result<()> {
     Ok(())
 }
 
-pub fn bins_start_end_ind(cargo_toml: &str) -> Result<(usize, usize)> {
-    let start_ind = cargo_toml
-        .find("bin = [")
-        .context("Failed to find the start of the `bin` list (`bin = [`)")?
-        + 7;
-    let end_ind = start_ind
-        + cargo_toml
-            .get(start_ind..)
-            .and_then(|slice| slice.as_bytes().iter().position(|c| *c == b']'))
-            .context("Failed to find the end of the `bin` list (`]`)")?;
-
-    Ok((start_ind, end_ind))
-}
-
-pub fn append_bins(
-    buf: &mut Vec<u8>,
-    exercise_infos: &[ExerciseInfo],
-    exercise_path_prefix: &[u8],
-) {
-    buf.push(b'\n');
-    for exercise_info in exercise_infos {
-        buf.extend_from_slice(b"  { name = \"");
-        buf.extend_from_slice(exercise_info.name.as_bytes());
-        buf.extend_from_slice(b"\", path = \"");
-        buf.extend_from_slice(exercise_path_prefix);
-        buf.extend_from_slice(b"exercises/");
-        if let Some(dir) = &exercise_info.dir {
-            buf.extend_from_slice(dir.as_bytes());
-            buf.push(b'/');
-        }
-        buf.extend_from_slice(exercise_info.name.as_bytes());
-        buf.extend_from_slice(b".rs\" },\n");
-    }
-}
-
 fn check_cargo_toml(
     exercise_infos: &[ExerciseInfo],
     current_cargo_toml: &str,
@@ -183,7 +149,13 @@ fn check_cargo_toml(
     append_bins(&mut new_bins, exercise_infos, exercise_path_prefix);
 
     if old_bins != new_bins {
-        bail!("`Cargo.toml` is outdated. Run `rustlings dev update` to update it");
+        if DEBUG_PROFILE {
+            bail!("The file `dev/Cargo.toml` is outdated. Please run `cargo run -- dev update` to update it");
+        } else {
+            bail!(
+                "The file `Cargo.toml` is outdated. Please run `rustlings dev update` to update it",
+            );
+        }
     }
 
     Ok(())
@@ -198,14 +170,11 @@ pub fn check() -> Result<()> {
             &info_file.exercises,
             include_str!("../../dev/Cargo.toml"),
             b"../",
-        )
-        .context("The file `dev/Cargo.toml` is outdated. Please run `cargo run -- dev update` to update it")?;
+        )?;
     } else {
         let current_cargo_toml =
             fs::read_to_string("Cargo.toml").context("Failed to read the file `Cargo.toml`")?;
-        check_cargo_toml(&info_file.exercises, &current_cargo_toml, b"").context(
-            "The file `Cargo.toml` is outdated. Please run `rustlings dev update` to update it",
-        )?;
+        check_cargo_toml(&info_file.exercises, &current_cargo_toml, b"")?;
     }
 
     println!("\nEverything looks fine!");

src/dev/update.rs

@@ -3,26 +3,22 @@ use std::fs;
 use anyhow::{Context, Result};
 
 use crate::{
+    cargo_toml::updated_cargo_toml,
     info_file::{ExerciseInfo, InfoFile},
     DEBUG_PROFILE,
 };
 
-use super::check::{append_bins, bins_start_end_ind};
-
 fn update_cargo_toml(
     exercise_infos: &[ExerciseInfo],
     current_cargo_toml: &str,
-    cargo_toml_path: &str,
     exercise_path_prefix: &[u8],
+    cargo_toml_path: &str,
 ) -> Result<()> {
-    let (bins_start_ind, bins_end_ind) = bins_start_end_ind(current_cargo_toml)?;
+    let updated_cargo_toml =
+        updated_cargo_toml(exercise_infos, current_cargo_toml, exercise_path_prefix)?;
 
-    let mut new_cargo_toml = Vec::with_capacity(1 << 13);
-    new_cargo_toml.extend_from_slice(current_cargo_toml[..bins_start_ind].as_bytes());
-    append_bins(&mut new_cargo_toml, exercise_infos, exercise_path_prefix);
-    new_cargo_toml.extend_from_slice(current_cargo_toml[bins_end_ind..].as_bytes());
-
-    fs::write(cargo_toml_path, new_cargo_toml).context("Failed to write the `Cargo.toml` file")?;
+    fs::write(cargo_toml_path, updated_cargo_toml)
+        .context("Failed to write the `Cargo.toml` file")?;
 
     Ok(())
 }
@@ -34,8 +30,8 @@ pub fn update() -> Result<()> {
         update_cargo_toml(
             &info_file.exercises,
             include_str!("../../dev/Cargo.toml"),
-            "dev/Cargo.toml",
             b"../",
+            "dev/Cargo.toml",
         )
         .context("Failed to update the file `dev/Cargo.toml`")?;
 
@@ -43,7 +39,7 @@ pub fn update() -> Result<()> {
     } 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, "Cargo.toml", b"")
+        update_cargo_toml(&info_file.exercises, &current_cargo_toml, b"", "Cargo.toml")
             .context("Failed to update the file `Cargo.toml`")?;
 
         println!("Updated `Cargo.toml`");