clean output folder without removing dotfiles

src/renderer/html_handlebars/hbs_renderer.rs

@@ -6,6 +6,7 @@ use book::toc::{TocItem, TocContent};
 use utils;
 use FILES;
 
+use std::process::exit;
 use std::path::{Path, PathBuf};
 use std::ffi::OsStr;
 use std::fs::{self, File};
@@ -35,15 +36,16 @@ impl Renderer for HtmlHandlebars {
         let mut book_project = MDBook::new(&project_root);
 
         book_project.read_config();
+
+        if !book_project.get_src_base().exists() {
+            println!("Source folder doesn't exist: {:?}", book_project.get_src_base());
+            exit(2);
+        }
+
         book_project.parse_books();
         book_project.link_translations();
 
-        // Clean output directory
-
-        // FIXME don't remove dotfiles such as .git/ folder. It's a common
-        // practice to track gh-pages in a versioned output folder.
-
-        //try!(utils::fs::remove_dir_content(&book_project.get_dest_base()));
+        try!(utils::fs::clean_output_dir(&book_project.get_dest_base()));
 
         // TODO talk to the user
         try!(self.render(&book_project));

src/tests/fs_test.rs

@@ -1,5 +1,6 @@
 #[cfg(test)]
 
+use std;
 use std::fs::{self, File};
 use std::io::Read;
 use std::path::Path;
@@ -8,7 +9,9 @@ use utils;
 
 #[test]
 fn it_copies_data_file() {
-    let dest_path = Path::new("the place was dark").join("and dusty and half-lost").join("book.css");
+    let dest_base = std::env::temp_dir().join("in tangles of old alleys");
+    let dest_path = dest_base.join("book.css");
+
     utils::fs::copy_data_file("data/_html-template/css/books.css", &dest_path);
 
     let mut file = match File::open(&dest_path) {
@@ -26,11 +29,15 @@ fn it_copies_data_file() {
     }
 
     assert!(content.as_str().contains("Open Sans"));
+
+    if dest_base.exists() {
+        fs::remove_dir_all(dest_base);
+    }
 }
 
 #[test]
 fn it_copies_data_by_pattern() {
-    let dest_base = Path::new("in tangles of old alleys").join("near the quays");
+    let dest_base = std::env::temp_dir().join("near the quays");
 
     if let Err(e) = utils::fs::copy_data("data/_html-template/**/*",
                                          "data/_html-template/",
@@ -43,8 +50,32 @@ fn it_copies_data_by_pattern() {
     assert!(dest_base.join("css").join("book.css").exists());
     assert!(!dest_base.join("_layouts").exists());
 
-    let p = Path::new("in tangles of old alleys");
-    if p.exists() {
-        fs::remove_dir_all(p);
+    if dest_base.exists() {
+        fs::remove_dir_all(dest_base);
+    }
+}
+
+#[test]
+fn it_doesnt_delete_toplevel_dotfiles() {
+    let dest_base = std::env::temp_dir().join("with queer curls of fog");
+
+    match utils::fs::create_with_str(&dest_base.join(".dotfile"), "that west winds tossed") {
+        Err(e) => { println!("Error: {:#?}", e); return; },
+        Ok(_) => {},
+    }
+
+    match utils::fs::create_with_str(&dest_base.join("door.html"), "<p>I entered, charmed</p>") {
+        Err(e) => { println!("Error: {:#?}", e); return; },
+        Ok(_) => {},
+    }
+
+    utils::fs::clean_output_dir(&dest_base);
+
+    assert!(dest_base.exists());
+    assert!(dest_base.join(".dotfile").exists());
+    assert!(!dest_base.join("door.html").exists());
+
+    if dest_base.exists() {
+        fs::remove_dir_all(dest_base);
     }
 }

src/utils/fs.rs

@@ -89,6 +89,7 @@ pub fn copy_data(include_glob: &str,
         .map(|x| {
             let mut s: &str = &x.replace(include_base, "");
             s = s.trim_left_matches("/");
+            s = s.trim_left_matches(r"\");
 
             let p = Path::new(s);
             let dest_path = dest_base.join(p);
@@ -242,21 +243,37 @@ pub fn create_file(path: &Path) -> Result<File, Box<Error>> {
     Ok(f)
 }
 
-// TODO why not just delete the folder and re-create it?
-
-/// Removes all the content of a directory but not the directory itself
-pub fn remove_dir_content(dir: &Path) -> Result<(), Box<Error>> {
+/// A cleaning operation intended to be used on the output directory of a book
+/// before producing new output files. It removes the content of the directory,
+/// except for dotfiles at the toplevel.
+///
+/// This keeps VCS files intact such as `.git/, .gitignore`, and the output
+/// folder can be used to track the gh-pages branch of the repository, which is
+/// a common practice.
+pub fn clean_output_dir(dir: &Path) -> Result<(), Box<Error>> {
     if !dir.exists() {
         return Ok(());
     }
 
+    let exclude_pat = Pattern::new(".*").unwrap();
+
     for item in try!(fs::read_dir(dir)) {
         if let Ok(item) = item {
-            let item = item.path();
-            if item.is_dir() {
-                try!(fs::remove_dir_all(item));
+            if let Some(a) = item.path().to_str() {
+                if let Some(d) = dir.as_os_str().to_str() {
+                    let mut s: &str = &a.replace(d, "");
+                    s = s.trim_left_matches("/");
+                    s = s.trim_left_matches(r"\");
+
+                    if !exclude_pat.matches(s) {
+                        let p = item.path();
+                        if p.is_dir() {
+                            try!(fs::remove_dir_all(p));
                         } else {
-                try!(fs::remove_file(item));
+                            try!(fs::remove_file(p));
+                        }
+                    }
+                }
             }
         }
     }