detect file/directory removal and replacing a file with a directory or a directory with a file

also change changes/actions print style for brevity

src/update_index.rs

@@ -1,4 +1,4 @@
-use std::{fs, io, path::Path};
+use std::{collections::HashMap, fs, io, path::Path};
 
 use crate::{indexchanges::IndexChange, indexfile::IndexFile};
 
@@ -14,10 +14,15 @@ pub fn perform_index_diff(source: &Path, index: &Path) -> io::Result<Vec<IndexCh
     Ok(changes)
 }
 fn rec(
+    // location of source files
     source: &Path,
+    // relative path used on this iteration
     rel_path: &Path,
+    // location of the index
     index_files: &Path,
+    // list of changes to be made
     changes: &mut Vec<IndexChange>,
+    // if the index is part of `source`, where exactly is it?
     inner_index: Option<&Path>,
 ) -> Result<(), io::Error> {
     if let Some(ii) = &inner_index {
@@ -27,13 +32,31 @@ fn rec(
         }
     }
 
-    if !index_files.join(rel_path).try_exists()? {
-        changes.push(IndexChange::AddDir(rel_path.to_path_buf()));
-    }
-    for entry in fs::read_dir(source.join(rel_path))? {
+    // used to find removals
+    let index_rel_path = index_files.join(rel_path);
+    let mut index_entries = match fs::read_dir(&index_rel_path) {
+        Err(_) => {
+            changes.push(IndexChange::AddDir(rel_path.to_path_buf()));
+            HashMap::new()
+        }
+        Ok(e) => e
+            .into_iter()
+            .filter_map(|v| v.ok())
+            .map(|v| Ok((v.file_name(), v.file_type()?.is_dir())))
+            .collect::<Result<_, io::Error>>()?,
+    };
+    // compare source files with index
+    let source_files = fs::read_dir(source.join(rel_path))?.collect::<Vec<_>>();
+    // find changes/adds
+    for entry in source_files {
         let entry = entry?;
         let metadata = entry.metadata()?;
+        let in_index_and_is_dir = index_entries.remove(&entry.file_name());
         if metadata.is_dir() {
+            if let Some(false) = in_index_and_is_dir {
+                // is dir, but was file -> remove file
+                changes.push(IndexChange::RemoveFile(rel_path.join(entry.file_name())));
+            }
             rec(
                 source,
                 &rel_path.join(entry.file_name()),
@@ -42,6 +65,10 @@ fn rec(
                 inner_index,
             )?;
         } else {
+            if let Some(true) = in_index_and_is_dir {
+                // is file, but was dir -> remove dir
+                changes.push(IndexChange::RemoveDir(rel_path.join(entry.file_name())));
+            }
             let newif = IndexFile::new_from_metadata(&metadata);
             let oldif = IndexFile::from_path(&index_files.join(rel_path).join(entry.file_name()));
             match oldif {
@@ -53,5 +80,13 @@ fn rec(
             }
         }
     }
+    // removals
+    for (removed_file, is_dir) in index_entries {
+        changes.push(if is_dir {
+            IndexChange::RemoveDir(rel_path.join(removed_file))
+        } else {
+            IndexChange::RemoveFile(rel_path.join(removed_file))
+        });
+    }
     Ok(())
 }