derive Debug for TextArea struct (fixes #23)

src/history.rs

@@ -1,6 +1,6 @@
 use std::collections::VecDeque;
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum EditKind {
     InsertChar(char, usize),
     DeleteChar(char, usize),
@@ -54,7 +54,7 @@ impl EditKind {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Edit {
     kind: EditKind,
     cursor_before: (usize, usize),
@@ -93,7 +93,7 @@ impl Edit {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct History {
     index: usize,
     max_items: usize,

src/textarea.rs

@@ -44,7 +44,7 @@ use crate::word::{find_word_end_forward, find_word_start_backward};
 /// // Get lines as String.
 /// println!("Lines: {:?}", textarea.lines());
 /// ```
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct TextArea<'a> {
     lines: Vec<String>,
     block: Option<Block<'a>>,

src/widget.rs

@@ -15,7 +15,7 @@ use std::sync::atomic::{AtomicU64, Ordering};
 // point we stick with using `tui::terminal::Frame::render_widget` because it is simpler API. Users don't need to
 // manage states of textarea instances separately.
 // https://docs.rs/tui/latest/tui/terminal/struct.Frame.html#method.render_stateful_widget
-#[derive(Default)]
+#[derive(Default, Debug)]
 pub struct Viewport(AtomicU64);
 
 impl Clone for Viewport {