docs: use doc comments and doc tests

src/identifier.rs

@@ -1,35 +1,34 @@
 #![allow(clippy::module_name_repetitions)]
 
+/// Reference to a [`TreeItem`](crate::TreeItem) in a [`Tree`](crate::Tree)
 pub type TreeIdentifier<'a> = &'a [usize];
+/// Reference to a [`TreeItem`](crate::TreeItem) in a [`Tree`](crate::Tree)
 pub type TreeIdentifierVec = Vec<usize>;
 
-pub fn get_without_leaf(identifier: &[usize]) -> (&[usize], Option<&usize>) {
+/// Split a [`TreeIdentifier`] into its branch and leaf
+///
+/// # Examples
+///
+/// ```
+/// # use tui_tree_widget::get_identifier_without_leaf;
+/// let (branch, leaf) = get_identifier_without_leaf(&[2, 4, 6]);
+/// assert_eq!(branch, [2, 4]);
+/// assert_eq!(leaf, Some(&6));
+///
+/// let (branch, leaf) = get_identifier_without_leaf(&[2]);
+/// assert_eq!(branch, []);
+/// assert_eq!(leaf, Some(&2));
+///
+/// let (branch, leaf) = get_identifier_without_leaf(&[]);
+/// assert_eq!(branch, []);
+/// assert_eq!(leaf, None);
+/// ```
+pub fn get_without_leaf(identifier: TreeIdentifier) -> (TreeIdentifier, Option<&usize>) {
     let length = identifier.len();
     let length_without_leaf = length.saturating_sub(1);
 
-    let head = &identifier[0..length_without_leaf];
-    let tail = identifier.get(length_without_leaf);
+    let branch = &identifier[0..length_without_leaf];
+    let leaf = identifier.get(length_without_leaf);
 
-    (head, tail)
-}
-
-#[test]
-fn get_without_leaf_empty() {
-    let (head, tail) = get_without_leaf(&[]);
-    assert_eq!(head.len(), 0);
-    assert_eq!(tail, None);
-}
-
-#[test]
-fn get_without_leaf_single() {
-    let (head, tail) = get_without_leaf(&[2]);
-    assert_eq!(head.len(), 0);
-    assert_eq!(tail, Some(&2));
-}
-
-#[test]
-fn get_without_leaf_multiple() {
-    let (head, tail) = get_without_leaf(&[2, 4, 6]);
-    assert_eq!(head, [2, 4]);
-    assert_eq!(tail, Some(&6));
+    (branch, leaf)
 }