refactor: add Justfile; fix some clippy lints

backup/src/delta.rs

@@ -5,7 +5,7 @@ use serde::{Deserialize, Serialize};
 use super::State;
 
 /// Represents the changes relative to the previous backup
-#[derive(Debug, Serialize, Deserialize, Clone)]
+#[derive(Debug, Serialize, Deserialize, Clone, Default)]
 pub struct Delta {
     /// What files were added/modified in each part of the tarball.
     pub added: State,
@@ -17,13 +17,6 @@ pub struct Delta {
 }
 
 impl Delta {
-    pub fn new() -> Self {
-        Self {
-            added: State::new(),
-            removed: State::new(),
-        }
-    }
-
     /// Returns whether the delta is empty by checking whether both its added and removed state
     /// return true for their `is_empty`.
     #[allow(dead_code)]

backup/src/lib.rs

@@ -129,7 +129,7 @@ impl<T: Clone> Backup<T> {
         let enc = GzEncoder::new(tar_gz, Compression::default());
         let mut ar = tar::Builder::new(enc);
 
-        let mut delta = Delta::new();
+        let mut delta = Delta::default();
 
         for (dir_in_tar, src_dir) in dirs {
             let mut added_files: HashSet<PathBuf> = HashSet::new();
@@ -187,7 +187,7 @@ impl<T: Clone> Backup<T> {
         let enc = GzEncoder::new(tar_gz, Compression::default());
         let mut ar = tar::Builder::new(enc);
 
-        let mut delta = Delta::new();
+        let mut delta = Delta::default();
 
         for (dir_in_tar, src_dir) in dirs {
             let mut all_files: HashSet<PathBuf> = HashSet::new();

backup/src/state.rs

@@ -11,14 +11,10 @@ use crate::Delta;
 
 /// Struct that represents a current state for a backup. This struct acts as a smart pointer around
 /// a HashMap.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Default)]
 pub struct State(HashMap<PathBuf, HashSet<PathBuf>>);
 
 impl State {
-    pub fn new() -> Self {
-        State(HashMap::new())
-    }
-
     /// Apply the delta to the current state.
     pub fn apply(&mut self, delta: &Delta) {
         // First we add new files, then we remove the old ones
@@ -61,7 +57,7 @@ where
     T::Item: Borrow<Delta>,
 {
     fn from(deltas: T) -> Self {
-        let mut state = State::new();
+        let mut state = State::default();
 
         for delta in deltas {
             state.apply(delta.borrow());
@@ -90,9 +86,3 @@ impl DerefMut for State {
         &mut self.0
     }
 }
-
-impl Default for State {
-    fn default() -> Self {
-        Self::new()
-    }
-}