Vendor dependencies

Let's see how I like this workflow.

vendor/tui/tests/terminal.rs

@@ -0,0 +1,36 @@
+use std::error::Error;
+use tui::{
+    backend::{Backend, TestBackend},
+    layout::Rect,
+    widgets::Paragraph,
+    Terminal,
+};
+
+#[test]
+fn terminal_buffer_size_should_be_limited() {
+    let backend = TestBackend::new(400, 400);
+    let terminal = Terminal::new(backend).unwrap();
+    let size = terminal.backend().size().unwrap();
+    assert_eq!(size.width, 255);
+    assert_eq!(size.height, 255);
+}
+
+#[test]
+fn terminal_draw_returns_the_completed_frame() -> Result<(), Box<dyn Error>> {
+    let backend = TestBackend::new(10, 10);
+    let mut terminal = Terminal::new(backend)?;
+    let frame = terminal.draw(|f| {
+        let paragrah = Paragraph::new("Test");
+        f.render_widget(paragrah, f.size());
+    })?;
+    assert_eq!(frame.buffer.get(0, 0).symbol, "T");
+    assert_eq!(frame.area, Rect::new(0, 0, 10, 10));
+    terminal.backend_mut().resize(8, 8);
+    let frame = terminal.draw(|f| {
+        let paragrah = Paragraph::new("test");
+        f.render_widget(paragrah, f.size());
+    })?;
+    assert_eq!(frame.buffer.get(0, 0).symbol, "t");
+    assert_eq!(frame.area, Rect::new(0, 0, 8, 8));
+    Ok(())
+}