Refactor book processing to more concise functions

Author: Coi-l

src/cmd/shelf.rs

@@ -22,58 +22,78 @@ pub fn make_subcommand() -> Command {
     Command::new("shelf").about("Build a bookshelf from shelf.toml file")
 }
 
-fn process_book(
-    path: &str,
+struct BookContext {
+    title: String,
+    desc: String,
+    authors: String,
+}
+
+fn update_index(
     index_file: &mut File,
-    summary: &mut File,
+    summary_file: &mut File,
     shelf_source: &PathBuf,
-    shelf_url: &PathBuf,
+    root_prefix: &str,
+    context: BookContext,
 ) -> Result<()> {
-    let book_dir = path.try_resolve()?;
-    let book_dir = std::fs::canonicalize(book_dir)?;
-    let mut book = MDBook::load(book_dir)?;
-
-    // Build book
-    let title = book.config.book.title.clone().unwrap();
-    let mut path = current_dir()?;
-    path.push(BOOKSHELF_DIR);
-    path.push(BOOKS_DIR);
-    path.push(title);
-    book.config.build.build_dir = path;
-    // Create back reference to bookshelf
-    book.config.book.shelf_url = Some(shelf_url.to_path_buf());
-    book.build()?;
-
-    let title = book.config.book.title.unwrap_or_default();
-    let book_link = format!("## [{title}](<../../{BOOKS_DIR}/{title}/{INDEX_HTML_FILE}>)");
-
     // Create post in index file
+    let book_link = format!(
+        "## [{title}](<{prefix}/{BOOKSHELF_DIR}/{BOOKS_DIR}/{title}/{INDEX_HTML_FILE}>)",
+        title = context.title,
+        prefix = root_prefix
+    );
     writeln!(index_file, "{book_link}")?;
     writeln!(index_file)?;
-    let desc = book.config.book.description.unwrap_or_default();
-    writeln!(index_file, "{desc}")?;
+    writeln!(index_file, "{desc}", desc = context.desc)?;
 
     // Create a separate chapter file for the book
-    let fixed_title = title.replace(' ', "_");
+    let fixed_title = context.title.replace(' ', "_");
     let file_name = format!("{fixed_title}.md");
     let mut file_path = shelf_source.clone();
     file_path.push(&file_name);
     let mut bf = File::create(file_path)?;
     writeln!(bf, "{book_link}")?;
     writeln!(bf)?;
-    writeln!(bf, "{desc}")?;
+    writeln!(bf, "{desc}", desc = context.desc)?;
     writeln!(bf)?;
     writeln!(bf)?;
-    let authors = book.config.book.authors.join(", ");
-    writeln!(bf, "*{authors}*")?;
+    writeln!(bf, "*{authors}*", authors = context.authors)?;
 
     // Add the chapter to the summary
-    writeln!(summary, "- [{title}](./{file_name})")?;
-    writeln!(summary)?;
+    writeln!(
+        summary_file,
+        "- [{title}](./{file_name})",
+        title = context.title
+    )?;
+    writeln!(summary_file)?;
 
     Ok(())
 }
 
+fn process_book(path: &str, shelf_url: &PathBuf) -> Result<BookContext> {
+    let book_dir = path.try_resolve()?;
+    let book_dir = std::fs::canonicalize(book_dir)?;
+    let mut book = MDBook::load(book_dir)?;
+
+    // Build book
+    let title = book.config.book.title.clone().unwrap();
+    let mut path = current_dir()?;
+    path.push(BOOKSHELF_DIR);
+    path.push(BOOKS_DIR);
+    path.push(title);
+    book.config.build.build_dir = path;
+    // Create back reference to bookshelf
+    book.config.book.shelf_url = Some(shelf_url.to_owned());
+    book.build()?;
+
+    let book_context = BookContext {
+        title: book.config.book.title.unwrap_or_default(),
+        desc: book.config.book.description.unwrap_or_default(),
+        authors: book.config.book.authors.join(", "),
+    };
+
+    Ok(book_context)
+}
+
 pub fn execute(_args: &ArgMatches) -> Result<()> {
     let mut file = File::open("shelf.toml")?;
     let mut contents = String::new();
@@ -107,9 +127,9 @@ pub fn execute(_args: &ArgMatches) -> Result<()> {
 
     let mut summary_file_name = shelf_book.source_dir();
     summary_file_name.push("SUMMARY.md");
-    let mut summary = File::create(summary_file_name).unwrap();
-    writeln!(summary, "# Summary")?;
-    writeln!(summary, "- [Index](./{INDEX_MD_FILE})")?;
+    let mut summary_file = File::create(summary_file_name).unwrap();
+    writeln!(summary_file, "# Summary")?;
+    writeln!(summary_file, "- [Index](./{INDEX_MD_FILE})")?;
 
     for sb in &shelf_config.books {
         let book_path = if let Some(url) = &sb.git_url {
@@ -122,13 +142,14 @@ pub fn execute(_args: &ArgMatches) -> Result<()> {
         };
 
         if let Some(path) = book_path {
-            process_book(
-                &path,
+            let update_context = process_book(&path, &shelf_url)?;
+            let _ = update_index(
                 &mut index_file,
-                &mut summary,
+                &mut summary_file,
                 &shelf_source,
-                &shelf_url,
-            )?
+                &shelf_url_prefix,
+                update_context,
+            )?;
         }
     }