add preserve_dotfiles_in_output configuration option (#1985)

components/config/src/config/mod.rs

@@ -78,6 +78,8 @@ pub struct Config {
     pub mode: Mode,
 
     pub output_dir: String,
+    /// Whether dotfiles inside the output directory are preserved when rebuilding the site
+    pub preserve_dotfiles_in_output: bool,
 
     pub link_checker: link_checker::LinkChecker,
     /// The setup for which slugification strategies to use for paths, taxonomies and anchors
@@ -371,6 +373,7 @@ impl Default for Config {
             ignored_content_globset: None,
             translations: HashMap::new(),
             output_dir: "public".to_string(),
+            preserve_dotfiles_in_output: false,
             link_checker: link_checker::LinkChecker::default(),
             slugify: slugify::Slugify::default(),
             search: search::Search::default(),

components/site/src/lib.rs

@@ -6,7 +6,7 @@ pub mod sitemap;
 pub mod tpls;
 
 use std::collections::HashMap;
-use std::fs::remove_dir_all;
+use std::fs::{remove_dir_all, remove_file};
 use std::path::{Path, PathBuf};
 use std::sync::{Arc, Mutex, RwLock};
 
@@ -23,6 +23,7 @@ use std::time::Instant;
 use templates::{load_tera, render_redirect_template};
 use utils::fs::{
     copy_directory, copy_file_if_needed, create_directory, create_file, ensure_directory_exists,
+    is_dotfile,
 };
 use utils::net::get_available_port;
 use utils::templates::{render_template, ShortcodeDefinition};
@@ -583,11 +584,34 @@ impl Site {
         imageproc.do_process()
     }
 
-    /// Deletes the `public` directory if it exists
+    /// Deletes the `public` directory if it exists and the `preserve_dotfiles_in_output` option is set to false,
+    /// or if set to true: its contents except for the dotfiles at the root level.
     pub fn clean(&self) -> Result<()> {
         if self.output_path.exists() {
-            // Delete current `public` directory so we can start fresh
-            remove_dir_all(&self.output_path).context("Couldn't delete output directory")?;
+            if !self.config.preserve_dotfiles_in_output {
+                return remove_dir_all(&self.output_path)
+                    .context("Couldn't delete output directory");
+            }
+
+            for entry in self.output_path.read_dir().context(format!(
+                "Couldn't read output directory `{}`",
+                self.output_path.display()
+            ))? {
+                let entry = entry.context("Couldn't read entry in output directory")?.path();
+
+                // Skip dotfiles if the preserve_dotfiles_in_output configuration option is set
+                if is_dotfile(&entry) {
+                    continue;
+                }
+
+                if entry.is_dir() {
+                    remove_dir_all(entry)
+                        .context("Couldn't delete folder while cleaning the output directory")?;
+                } else {
+                    remove_file(entry)
+                        .context("Couldn't delete file while cleaning the output directory")?;
+                }
+            }
         }
 
         Ok(())

components/utils/src/fs.rs

@@ -166,6 +166,14 @@ where
     time_source.and_then(|ts| time_target.map(|tt| ts > tt)).unwrap_or(true)
 }
 
+/// Checks if the file or folder for the given path is a dotfile, meaning starts with '.'
+pub fn is_dotfile<P>(path: P) -> bool
+where
+    P: AsRef<Path>,
+{
+    path.as_ref().file_name().and_then(|s| s.to_str()).map(|s| s.starts_with('.')).unwrap_or(false)
+}
+
 #[cfg(test)]
 mod tests {
     use std::fs::{metadata, read_to_string, File};

docs/content/documentation/getting-started/configuration.md

@@ -41,6 +41,10 @@ theme = ""
 # For overriding the default output directory `public`, set it to another value (e.g.: "docs")
 output_dir = "public"
 
+# Whether dotfiles at the root level of the output directory are preserved when (re)building the site.
+# Enabling this also prevents the deletion of the output folder itself on rebuilds.
+preserve_dotfiles_in_output = false
+
 # When set to "true", the Sass files in the `sass` directory in the site root are compiled.
 # Sass files in theme directories are always compiled.
 compile_sass = false