Use proper defines for files and directories

src/cmd/shelf.rs

@@ -11,6 +11,12 @@ use mdbook::config::Shelf;
 use mdbook::errors::Result;
 use mdbook::MDBook;
 
+const SHELF_DIR: &str = "shelf";
+const REPOS_DIR: &str = "repositories";
+const INDEX_MD_FILE: &str = "index.md";
+const INDEX_HTML_FILE: &str = "index.html";
+const BOOKS_DIR: &str = "books";
+
 pub fn make_subcommand() -> Command {
     Command::new("shelf").about("Build a bookshelf from shelf.toml file")
 }
@@ -23,15 +29,18 @@ fn process_book(path: &str, index_file: &mut File, summary: &mut File) -> Result
     // Build book
     let mut path = current_dir()?;
     let title = book.config.book.title.clone().unwrap();
-    path.push("books/");
+    path.push(BOOKS_DIR);
     path.push(title);
     book.config.build.build_dir = path;
     book.config.book.shelf_url = Some(PathBuf::from(r"../../shelf/book/index.html"));
     book.build()?;
 
     // Create post in index file
     let title = book.config.book.title.unwrap_or_default();
-    writeln!(index_file, "## [{title}](<../../books/{title}/index.html>)")?;
+    writeln!(
+        index_file,
+        "## [{title}](<../../{BOOKS_DIR}/{title}/{INDEX_HTML_FILE}>)"
+    )?;
     writeln!(index_file)?;
     let desc = book.config.book.description.unwrap_or_default();
     writeln!(index_file, "{desc}")?;
@@ -57,12 +66,12 @@ pub fn execute(_args: &ArgMatches) -> Result<()> {
     file.read_to_string(&mut contents)?;
     let shelf: Shelf = toml::from_str(&contents)?;
 
-    let _ = std::fs::remove_dir_all("shelf");
-    let _ = std::fs::remove_dir_all("repositories");
-    let shelf_book = MDBook::init("shelf").create_gitignore(false).build()?;
+    let _ = std::fs::remove_dir_all(SHELF_DIR);
+    let _ = std::fs::remove_dir_all(REPOS_DIR);
+    let shelf_book = MDBook::init(SHELF_DIR).create_gitignore(false).build()?;
 
     let mut index_file_name = shelf_book.source_dir();
-    index_file_name.push("index.md");
+    index_file_name.push(INDEX_MD_FILE);
     let mut index_file = File::create(index_file_name).unwrap();
     writeln!(index_file, "# Bookshelf")?;
     writeln!(index_file)?;
@@ -71,15 +80,15 @@ pub fn execute(_args: &ArgMatches) -> Result<()> {
     summary_file_name.push("SUMMARY.md");
     let mut summary = File::create(summary_file_name).unwrap();
     writeln!(summary, "# Summary")?;
-    writeln!(summary, "- [Index](./index.md)")?;
+    writeln!(summary, "- [Index](./{INDEX_MD_FILE})")?;
 
     for sb in &shelf.book {
         if let Some(url) = &sb.git_url {
             println!("{:?}", sb);
             let path = sb.path.clone().unwrap_or("root".to_owned());
             let repo_raw_name = url.split('/').last().unwrap_or(&path);
             let repo_name = format!("{repo_raw_name}-{path}");
-            let mut checkout_path = PathBuf::from("repositories");
+            let mut checkout_path = PathBuf::from(REPOS_DIR);
             checkout_path.push(repo_name);
 
             let book_path = if let Some(path) = &sb.path {