Add "dev update"

src/dev/check.rs

@@ -1,16 +1,83 @@
+use anyhow::{bail, Context, Result};
 use std::fs;
 
-use anyhow::{Context, Result};
+use crate::{
+    info_file::{ExerciseInfo, InfoFile},
+    DEVELOPING_OFFIFICAL_RUSTLINGS,
+};
 
-use crate::{info_file::InfoFile, init::cargo_toml};
+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,
+    exercise_path_prefix: &[u8],
+) -> Result<()> {
+    let (bins_start_ind, bins_end_ind) = bins_start_end_ind(current_cargo_toml)?;
+
+    let old_bins = &current_cargo_toml.as_bytes()[bins_start_ind..bins_end_ind];
+    let mut new_bins = Vec::with_capacity(1 << 13);
+    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+        bail!("`Cargo.toml` is outdated.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");
+    }
+
+    Ok(())
+}
+
+pub fn check() -> Result<()> {
+    let info_file = InfoFile::parse()?;
 
-pub fn check(info_file: InfoFile) -> Result<()> {
     // TODO: Add checks
 
-    // TODO: Keep dependencies!
-    fs::write("Cargo.toml", cargo_toml(&info_file.exercises))
-        .context("Failed to update the file `Cargo.toml`")?;
-    println!("Updated `Cargo.toml`");
+    if DEVELOPING_OFFIFICAL_RUSTLINGS {
+        check_cargo_toml(
+            &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",
+        )?;
+    }
 
     println!("\nEverything looks fine!");
 

src/dev/init.rs

@@ -1,6 +1,5 @@
-use std::fs::{self, create_dir};
-
 use anyhow::{Context, Result};
+use std::fs::{self, create_dir};
 
 use crate::CURRENT_FORMAT_VERSION;
 
@@ -19,11 +18,8 @@ pub fn init() -> Result<()> {
     )
     .context("Failed to create the file `rustlings/info.toml`")?;
 
-    fs::write(
-        "rustlings/Cargo.toml",
-        format!("{CARGO_TOML_COMMENT}{}", crate::init::CARGO_TOML_PACKAGE),
-    )
-    .context("Failed to create the file `rustlings/Cargo.toml`")?;
+    fs::write("rustlings/Cargo.toml", CARGO_TOML)
+        .context("Failed to create the file `rustlings/Cargo.toml`")?;
 
     fs::write("rustlings/.gitignore", crate::init::GITIGNORE)
         .context("Failed to create the file `rustlings/.gitignore`")?;
@@ -80,10 +76,17 @@ mode = "test"
 hint = """???"""
 "#;
 
-const CARGO_TOML_COMMENT: &str =
-    "# You shouldn't edit this file manually! It is updated by `rustlings dev check`
+const CARGO_TOML: &[u8] =
+    br#"# Don't edit the `bin` list manually! It is updated by `rustlings dev update`
+bin = []
 
-";
+[package]
+name = "rustlings"
+edition = "2021"
+publish = false
+
+[dependencies]
+"#;
 
 const README: &str = "# Rustlings 🦀
 

src/dev/update.rs

@@ -0,0 +1,53 @@
+use std::fs;
+
+use anyhow::{Context, Result};
+
+use crate::{
+    info_file::{ExerciseInfo, InfoFile},
+    DEVELOPING_OFFIFICAL_RUSTLINGS,
+};
+
+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],
+) -> Result<()> {
+    let (bins_start_ind, bins_end_ind) = bins_start_end_ind(current_cargo_toml)?;
+
+    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")?;
+
+    Ok(())
+}
+
+pub fn update() -> Result<()> {
+    let info_file = InfoFile::parse()?;
+
+    if DEVELOPING_OFFIFICAL_RUSTLINGS {
+        update_cargo_toml(
+            &info_file.exercises,
+            include_str!("../../dev/Cargo.toml"),
+            "dev/Cargo.toml",
+            b"../",
+        )
+        .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, "Cargo.toml", b"")
+            .context("Failed to update the file `Cargo.toml`")?;
+
+        println!("Updated `Cargo.toml`");
+    }
+
+    Ok(())
+}