API Cleanup - part 1 (#235)

.travis.yml

@@ -29,12 +29,4 @@ script:
   - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then cargo fmt --all -- --check; fi
   - cargo build
   - if [ "$TRAVIS_OS_NAME" = "windows" ]; then cargo test --all -- --nocapture --test-threads 1; else cargo test --all --exclude crossterm_winapi -- --nocapture --test-threads 1; fi
-  - |
+  - scripts/test-examples.sh
-    pushd examples/program_examples
-    for d in */ ; do
-      pushd "$d"
-      cargo build
-      if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then cargo fmt --all -- --check; fi
-      popd
-    done
-    popd

crossterm_cursor/src/cursor.rs

@@ -29,9 +29,7 @@ trait ITerminalCursor: Sync + Send {
     /// Goto location (`x`, `y`) in the current terminal window.
     fn goto(&self, x: u16, y: u16) -> Result<()>;
     /// Get the cursor location `(x, y)` in the current terminal window.
-    ///
+    fn pos(&self) -> Result<(u16, u16)>;
-    /// `(0, 0)` is returned in case of an error.
-    fn pos(&self) -> (u16, u16);
     /// Move cursor `n` times up
     fn move_up(&self, count: u16) -> Result<()>;
     /// Move the cursor `n` times to the right.

crossterm_cursor/src/cursor/ansi_cursor.rs

@@ -51,7 +51,7 @@ impl ITerminalCursor for AnsiCursor {
         Ok(())
     }
 
-    fn pos(&self) -> (u16, u16) {
+    fn pos(&self) -> Result<(u16, u16)> {
         get_cursor_position()
     }
 
@@ -115,13 +115,17 @@ mod tests {
     fn reset_safe_ansi() {
         if try_enable_ansi() {
             let cursor = AnsiCursor::new();
-            let (x, y) = cursor.pos();
+            let pos = cursor.pos();
+            assert!(pos.is_ok());
+            let (x, y) = pos.unwrap();
 
             assert!(cursor.save_position().is_ok());
             assert!(cursor.goto(5, 5).is_ok());
             assert!(cursor.reset_position().is_ok());
 
-            let (x_saved, y_saved) = cursor.pos();
+            let pos = cursor.pos();
+            assert!(pos.is_ok());
+            let (x_saved, y_saved) = pos.unwrap();
 
             assert_eq!(x, x_saved);
             assert_eq!(y, y_saved);
@@ -134,10 +138,14 @@ mod tests {
     fn goto_ansi() {
         if try_enable_ansi() {
             let cursor = AnsiCursor::new();
-            let (x_saved, y_saved) = cursor.pos();
+            let pos = cursor.pos();
+            assert!(pos.is_ok());
+            let (x_saved, y_saved) = pos.unwrap();
 
             assert!(cursor.goto(5, 5).is_ok());
-            let (x, y) = cursor.pos();
+            let pos = cursor.pos();
+            assert!(pos.is_ok());
+            let (x, y) = pos.unwrap();
 
             assert!(cursor.goto(x_saved, y_saved).is_ok());
 

crossterm_cursor/src/cursor/cursor.rs

@@ -59,32 +59,32 @@ impl TerminalCursor {
     ///
     /// # Remarks
     /// position is 0-based, which means we start counting at 0.
-    pub fn pos(&self) -> (u16, u16) {
+    pub fn pos(&self) -> Result<(u16, u16)> {
         self.cursor.pos()
     }
 
     /// Move the current cursor position `n` times up.
-    pub fn move_up(&mut self, count: u16) -> &mut TerminalCursor {
+    pub fn move_up(&mut self, count: u16) -> Result<&mut TerminalCursor> {
-        self.cursor.move_up(count).unwrap();
+        self.cursor.move_up(count)?;
-        self
+        Ok(self)
     }
 
     /// Move the current cursor position `n` times right.
-    pub fn move_right(&mut self, count: u16) -> &mut TerminalCursor {
+    pub fn move_right(&mut self, count: u16) -> Result<&mut TerminalCursor> {
-        self.cursor.move_right(count).unwrap();
+        self.cursor.move_right(count)?;
-        self
+        Ok(self)
     }
 
     /// Move the current cursor position `n` times down.
-    pub fn move_down(&mut self, count: u16) -> &mut TerminalCursor {
+    pub fn move_down(&mut self, count: u16) -> Result<&mut TerminalCursor> {
-        self.cursor.move_down(count).unwrap();
+        self.cursor.move_down(count)?;
-        self
+        Ok(self)
     }
 
     /// Move the current cursor position `n` times left.
-    pub fn move_left(&mut self, count: u16) -> &mut TerminalCursor {
+    pub fn move_left(&mut self, count: u16) -> Result<&mut TerminalCursor> {
         self.cursor.move_left(count).unwrap();
-        self
+        Ok(self)
     }
 
     /// Save cursor position for recall later.

crossterm_cursor/src/cursor/winapi_cursor.rs

@@ -24,31 +24,31 @@ impl ITerminalCursor for WinApiCursor {
         Ok(())
     }
 
-    fn pos(&self) -> (u16, u16) {
+    fn pos(&self) -> Result<(u16, u16)> {
-        let cursor = Cursor::new().unwrap();
+        let cursor = Cursor::new()?;
-        cursor.position().map(Into::into).unwrap_or((0, 0))
+        Ok(cursor.position()?.into())
     }
 
     fn move_up(&self, count: u16) -> Result<()> {
-        let (xpos, ypos) = self.pos();
+        let (xpos, ypos) = self.pos()?;
         self.goto(xpos, ypos - count)?;
         Ok(())
     }
 
     fn move_right(&self, count: u16) -> Result<()> {
-        let (xpos, ypos) = self.pos();
+        let (xpos, ypos) = self.pos()?;
         self.goto(xpos + count, ypos)?;
         Ok(())
     }
 
     fn move_down(&self, count: u16) -> Result<()> {
-        let (xpos, ypos) = self.pos();
+        let (xpos, ypos) = self.pos()?;
         self.goto(xpos, ypos + count)?;
         Ok(())
     }
 
     fn move_left(&self, count: u16) -> Result<()> {
-        let (xpos, ypos) = self.pos();
+        let (xpos, ypos) = self.pos()?;
         self.goto(xpos - count, ypos)?;
         Ok(())
     }
@@ -87,7 +87,9 @@ mod tests {
         let cursor = WinApiCursor::new();
 
         assert!(cursor.goto(5, 5).is_ok());
-        let (x, y) = cursor.pos();
+        let pos = cursor.pos();
+        assert!(pos.is_ok());
+        let (x, y) = pos.unwrap();
 
         assert_eq!(x, 5);
         assert_eq!(y, 5);
@@ -96,13 +98,18 @@ mod tests {
     #[test]
     fn reset_safe_winapi() {
         let cursor = WinApiCursor::new();
-        let (x, y) = cursor.pos();
+
+        let pos = cursor.pos();
+        assert!(pos.is_ok());
+        let (x, y) = pos.unwrap();
 
         assert!(cursor.save_position().is_ok());
         assert!(cursor.goto(5, 5).is_ok());
         assert!(cursor.reset_position().is_ok());
 
-        let (x_saved, y_saved) = cursor.pos();
+        let pos = cursor.pos();
+        assert!(pos.is_ok());
+        let (x_saved, y_saved) = pos.unwrap();
 
         assert_eq!(x, x_saved);
         assert_eq!(y, y_saved);

crossterm_cursor/src/sys/unix.rs

@@ -7,11 +7,11 @@ use crossterm_utils::{
 };
 
 #[cfg(unix)]
-pub fn get_cursor_position() -> (u16, u16) {
+pub fn get_cursor_position() -> Result<(u16, u16)> {
     if unsafe { RAW_MODE_ENABLED } {
-        pos_raw().unwrap_or((0, 0))
+        pos_raw()
     } else {
-        pos().unwrap_or((0, 0))
+        pos()
     }
 }
 
@@ -45,33 +45,17 @@ pub fn pos_raw() -> Result<(u16, u16)> {
     stdin.lock().read_until(b'[', &mut vec![])?;
 
     let mut rows = vec![];
-    stdin.lock().read_until(b';', &mut rows).unwrap();
+    stdin.lock().read_until(b';', &mut rows)?;
 
     let mut cols = vec![];
-    stdin.lock().read_until(b'R', &mut cols).unwrap();
+    stdin.lock().read_until(b'R', &mut cols)?;
 
     // remove delimiter
     rows.pop();
     cols.pop();
 
-    let rows = rows
+    let rows = String::from_utf8(rows)?.parse::<u16>()?;
-        .into_iter()
+    let cols = String::from_utf8(cols)?.parse::<u16>()?;
-        .map(|b| (b as char))
-        .fold(String::new(), |mut acc, n| {
-            acc.push(n);
-            acc
-        })
-        .parse::<usize>()
-        .unwrap();
-    let cols = cols
-        .into_iter()
-        .map(|b| (b as char))
-        .fold(String::new(), |mut acc, n| {
-            acc.push(n);
-            acc
-        })
-        .parse::<usize>()
-        .unwrap();
 
-    Ok(((cols - 1) as u16, (rows - 1) as u16))
+    Ok((cols - 1, rows - 1))
 }

crossterm_cursor/src/sys/winapi.rs

@@ -12,12 +12,9 @@ use crossterm_utils::Result;
 pub use crossterm_winapi::{is_true, Coord, Handle, HandleType, ScreenBuffer};
 
 #[cfg(windows)]
-pub fn get_cursor_position() -> (u16, u16) {
+pub fn get_cursor_position() -> Result<(u16, u16)> {
-    if let Ok(cursor) = Cursor::new() {
+    let cursor = Cursor::new()?;
-        cursor.position().unwrap().into()
+    Ok(cursor.position()?.into())
-    } else {
-        (0, 0)
-    }
 }
 
 #[cfg(windows)]

crossterm_terminal/README.md

@@ -90,26 +90,26 @@ use crossterm::terminal::{terminal,ClearType};
 let mut terminal = terminal();
 
 // Clear all lines in terminal;
-terminal.clear(ClearType::All);
+terminal.clear(ClearType::All)?;
 // Clear all cells from current cursor position down.
-terminal.clear(ClearType::FromCursorDown);
+terminal.clear(ClearType::FromCursorDown)?;
 // Clear all cells from current cursor position down.
-terminal.clear(ClearType::FromCursorUp);
+terminal.clear(ClearType::FromCursorUp)?;
 // Clear current line cells.
-terminal.clear(ClearType::CurrentLine);
+terminal.clear(ClearType::CurrentLine)?;
 // Clear all the cells until next line.
-terminal.clear(ClearType::UntilNewLine);
+terminal.clear(ClearType::UntilNewLine)?;
 
 // Get terminal size
-let (width, height) = terminal.terminal_size();
+let (width, height) = terminal.size()?;
 print!("X: {}, y: {}", width, height);
 
 // Scroll down, up 10 lines.
-terminal.scroll_down(10);
+terminal.scroll_down(10)?;
-terminal.scroll_up(10);
+terminal.scroll_up(10)?;
 
 // Set terminal size (width, height)
-terminal.set_size(10,10);
+terminal.set_size(10,10)?;
 
 // exit the current process.
 terminal.exit();

crossterm_terminal/src/sys/unix.rs

@@ -1,11 +1,13 @@
 use libc::{ioctl, winsize, STDOUT_FILENO, TIOCGWINSZ};
 
+use crossterm_utils::Result;
+
 pub fn exit() {
     ::std::process::exit(0);
 }
 
 /// Get the current terminal size.
-pub fn get_terminal_size() -> (u16, u16) {
+pub fn get_terminal_size() -> Result<(u16, u16)> {
     // http://rosettacode.org/wiki/Terminal_control/Dimensions#Library:_BSD_libc
     let mut size = winsize {
         ws_row: 0,
@@ -16,8 +18,8 @@ pub fn get_terminal_size() -> (u16, u16) {
     let r = unsafe { ioctl(STDOUT_FILENO, TIOCGWINSZ.into(), &mut size) };
 
     if r == 0 {
-        (size.ws_col, size.ws_row)
+        Ok((size.ws_col, size.ws_row))
     } else {
-        (0, 0)
+        Err(std::io::Error::last_os_error().into())
     }
 }

crossterm_terminal/src/sys/winapi.rs

@@ -1,3 +1,4 @@
+use crossterm_utils::Result;
 use crossterm_winapi::ScreenBuffer;
 
 /// Exit the current process.
@@ -6,11 +7,7 @@ pub fn exit() {
 }
 
 #[cfg(windows)]
-pub fn get_terminal_size() -> (u16, u16) {
+pub fn get_terminal_size() -> Result<(u16, u16)> {
-    if let Ok(buffer) = ScreenBuffer::current() {
+    let buffer = ScreenBuffer::current()?;
-        let size = buffer.info().unwrap().terminal_size();
+    Ok(buffer.info()?.terminal_size().into())
-        ((size.width + 1) as u16, (size.height + 1) as u16)
-    } else {
-        (0, 0)
-    }
 }

crossterm_terminal/src/terminal.rs

@@ -43,11 +43,11 @@ trait ITerminal {
     /// Clear the current cursor by specifying the clear type
     fn clear(&self, clear_type: ClearType) -> Result<()>;
     /// Get the terminal size (x,y)
-    fn terminal_size(&self) -> (u16, u16);
+    fn size(&self) -> Result<(u16, u16)>;
     /// Scroll `n` lines up in the current terminal.
-    fn scroll_up(&self, count: i16) -> Result<()>;
+    fn scroll_up(&self, count: u16) -> Result<()>;
     /// Scroll `n` lines down in the current terminal.
-    fn scroll_down(&self, count: i16) -> Result<()>;
+    fn scroll_down(&self, count: u16) -> Result<()>;
     /// Resize terminal to the given width and height.
-    fn set_size(&self, width: i16, height: i16) -> Result<()>;
+    fn set_size(&self, width: u16, height: u16) -> Result<()>;
 }

crossterm_terminal/src/terminal/ansi_terminal.rs

@@ -15,17 +15,17 @@ pub static CLEAR_FROM_CURRENT_LINE: &'static str = csi!("2K");
 pub static CLEAR_UNTIL_NEW_LINE: &'static str = csi!("K");
 
 #[inline]
-pub fn get_scroll_up_ansi(count: i16) -> String {
+pub fn get_scroll_up_ansi(count: u16) -> String {
     format!(csi!("{}S"), count)
 }
 
 #[inline]
-pub fn get_scroll_down_ansi(count: i16) -> String {
+pub fn get_scroll_down_ansi(count: u16) -> String {
     format!(csi!("{}T"), count)
 }
 
 #[inline]
-pub fn get_set_size_ansi(width: i16, height: i16) -> String {
+pub fn get_set_size_ansi(width: u16, height: u16) -> String {
     format!(csi!("8;{};{}t"), height, width)
 }
 
@@ -61,21 +61,21 @@ impl ITerminal for AnsiTerminal {
         Ok(())
     }
 
-    fn terminal_size(&self) -> (u16, u16) {
+    fn size(&self) -> Result<(u16, u16)> {
         get_terminal_size()
     }
 
-    fn scroll_up(&self, count: i16) -> Result<()> {
+    fn scroll_up(&self, count: u16) -> Result<()> {
         write_cout!(get_scroll_up_ansi(count))?;
         Ok(())
     }
 
-    fn scroll_down(&self, count: i16) -> Result<()> {
+    fn scroll_down(&self, count: u16) -> Result<()> {
         write_cout!(get_scroll_down_ansi(count))?;
         Ok(())
     }
 
-    fn set_size(&self, width: i16, height: i16) -> Result<()> {
+    fn set_size(&self, width: u16, height: u16) -> Result<()> {
         write_cout!(get_set_size_ansi(width, height))?;
         Ok(())
     }
@@ -100,7 +100,9 @@ mod tests {
             // see issue: https://github.com/eminence/terminal-size/issues/11
             thread::sleep(time::Duration::from_millis(30));
 
-            let (x, y) = terminal.terminal_size();
+            let size = terminal.size();
+            assert!(size.is_ok());
+            let (x, y) = size.unwrap();
 
             assert_eq!(x, 50);
             assert_eq!(y, 50);

crossterm_terminal/src/terminal/terminal.rs

@@ -70,19 +70,16 @@ impl Terminal {
         self.terminal.clear(clear_type)
     }
 
-    /// Get the terminal size (x,y).
+    /// Get the terminal size `(x,y)`.
-    ///
+    pub fn size(&self) -> Result<(u16, u16)> {
-    /// # Remark
+        self.terminal.size()
-    /// This will return a tuple of (x: u16, y: u16)
-    pub fn terminal_size(&self) -> (u16, u16) {
-        self.terminal.terminal_size()
     }
 
     /// Scroll `n` lines up in the current terminal.
     ///
     /// # Parameter
     /// - `count`: the number of rows should be shifted up.
-    pub fn scroll_up(&self, count: i16) -> Result<()> {
+    pub fn scroll_up(&self, count: u16) -> Result<()> {
         self.terminal.scroll_up(count)
     }
 
@@ -90,7 +87,7 @@ impl Terminal {
     ///
     /// # Parameter
     /// - `count`: the number of rows should be shifted down.
-    pub fn scroll_down(&self, count: i16) -> Result<()> {
+    pub fn scroll_down(&self, count: u16) -> Result<()> {
         self.terminal.scroll_down(count)
     }
 
@@ -103,7 +100,7 @@ impl Terminal {
     /// // Set of the size to X: 10 and Y: 10
     /// let size = term.set_size(10,10);
     /// ```
-    pub fn set_size(&self, width: i16, height: i16) -> Result<()> {
+    pub fn set_size(&self, width: u16, height: u16) -> Result<()> {
         self.terminal.set_size(width, height)
     }
 
@@ -143,7 +140,7 @@ pub fn terminal() -> Terminal {
 /// When executed, this command will scroll up the terminal buffer by the given number of times.
 ///
 /// See `crossterm/examples/command.rs` for more information on how to execute commands.
-pub struct ScrollUp(pub i16);
+pub struct ScrollUp(pub u16);
 
 impl Command for ScrollUp {
     type AnsiType = String;
@@ -161,7 +158,7 @@ impl Command for ScrollUp {
 /// When executed, this command will scroll down the terminal buffer by the given number of times.
 ///
 /// See `crossterm/examples/command.rs` for more information on how to execute commands.
-pub struct ScrollDown(pub i16);
+pub struct ScrollDown(pub u16);
 
 impl Command for ScrollDown {
     type AnsiType = String;
@@ -209,7 +206,7 @@ impl Command for Clear {
 /// When executed, this command will set the terminal sie to the given (`width` and `height`)
 ///
 /// See `crossterm/examples/command.rs` for more information on how to execute commands.
-pub struct SetSize(pub i16, pub i16);
+pub struct SetSize(pub u16, pub u16);
 
 impl Command for SetSize {
     type AnsiType = String;

crossterm_terminal/src/terminal/winapi_terminal.rs

@@ -41,15 +41,16 @@ impl ITerminal for WinApiTerminal {
         Ok(())
     }
 
-    fn terminal_size(&self) -> (u16, u16) {
+    fn size(&self) -> Result<(u16, u16)> {
         get_terminal_size()
     }
 
-    fn scroll_up(&self, count: i16) -> Result<()> {
+    fn scroll_up(&self, count: u16) -> Result<()> {
         let csbi = ScreenBuffer::current()?;
         let mut window = csbi.info()?.terminal_window();
 
         // Check whether the window is too close to the screen buffer top
+        let count = count as i16;
         if window.top >= count {
             window.top -= count; // move top down
             window.bottom = count; // move bottom down
@@ -59,13 +60,14 @@ impl ITerminal for WinApiTerminal {
         Ok(())
     }
 
-    fn scroll_down(&self, count: i16) -> Result<()> {
+    fn scroll_down(&self, count: u16) -> Result<()> {
         let screen_buffer = ScreenBuffer::current()?;
         let csbi = screen_buffer.info()?;
         let mut window = csbi.terminal_window();
         let buffer_size = csbi.buffer_size();
 
         // Check whether the window is too close to the screen buffer top
+        let count = count as i16;
         if window.bottom < buffer_size.height - count {
             window.top += count; // move top down
             window.bottom += count; // move bottom down
@@ -76,7 +78,7 @@ impl ITerminal for WinApiTerminal {
     }
 
     /// Set the current terminal size
-    fn set_size(&self, width: i16, height: i16) -> Result<()> {
+    fn set_size(&self, width: u16, height: u16) -> Result<()> {
         if width <= 0 {
             return Err(ErrorKind::ResizingTerminalFailure(String::from(
                 "Cannot set the terminal width lower than 1",
@@ -103,6 +105,7 @@ impl ITerminal for WinApiTerminal {
         // buffer to be large enough.  Include window position.
         let mut resize_buffer = false;
 
+        let width = width as i16;
         if current_size.width < window.left + width {
             if window.left >= i16::max_value() - width {
                 return Err(ErrorKind::ResizingTerminalFailure(String::from(
@@ -113,6 +116,7 @@ impl ITerminal for WinApiTerminal {
             new_size.width = window.left + width;
             resize_buffer = true;
         }
+        let height = height as i16;
         if current_size.height < window.top + height {
             if window.top >= i16::max_value() - height {
                 return Err(ErrorKind::ResizingTerminalFailure(String::from(
@@ -284,7 +288,9 @@ mod tests {
 
         assert!(terminal.set_size(30, 30).is_ok());
 
-        let (x, y) = terminal.terminal_size();
+        let size = terminal.size();
+        assert!(size.is_ok());
+        let (x, y) = size.unwrap();
 
         assert_eq!(x, 30);
         assert_eq!(y, 30);

crossterm_utils/src/error.rs

@@ -13,6 +13,8 @@ pub type Result<T> = std::result::Result<T, ErrorKind>;
 pub enum ErrorKind {
     IoError(io::Error),
     FmtError(fmt::Error),
+    Utf8Error(std::string::FromUtf8Error),
+    ParseIntError(std::num::ParseIntError),
     ResizingTerminalFailure(String),
 
     #[doc(hidden)]
@@ -49,3 +51,15 @@ impl From<fmt::Error> for ErrorKind {
         ErrorKind::FmtError(e)
     }
 }
+
+impl From<std::string::FromUtf8Error> for ErrorKind {
+    fn from(e: std::string::FromUtf8Error) -> Self {
+        ErrorKind::Utf8Error(e)
+    }
+}
+
+impl From<std::num::ParseIntError> for ErrorKind {
+    fn from(e: std::num::ParseIntError) -> Self {
+        ErrorKind::ParseIntError(e)
+    }
+}

crossterm_winapi/src/csbi.rs

@@ -17,14 +17,14 @@ impl ScreenBufferInfo {
 
     /// This will return the buffer size.
     ///
-    /// Will take `dwSize`from the current screen buffer and convert it into the `Size`.
+    /// Will take `dwSize` from the current screen buffer and convert it into the `Size`.
     pub fn buffer_size(&self) -> Size {
         Size::from(self.0.dwSize)
     }
 
     /// This will return the terminal size.
     ///
-    /// Will calculate the whit and height from `srWindow` and convert it into a `Size`.
+    /// Will calculate the width and height from `srWindow` and convert it into a `Size`.
     pub fn terminal_size(&self) -> Size {
         (Size::new(
             self.0.srWindow.Right - self.0.srWindow.Left,

examples/command_bar.rs

@@ -6,10 +6,10 @@ use crossterm::{
     Terminal, TerminalCursor,
 };
 
-fn log(input_buf: Arc<Mutex<String>>) -> Vec<thread::JoinHandle<()>> {
+fn log(input_buf: Arc<Mutex<String>>) -> Result<Vec<thread::JoinHandle<()>>> {
     let mut threads = Vec::with_capacity(10);
 
-    let (_, term_height) = terminal().terminal_size();
+    let (_, term_height) = terminal().size()?;
 
     for i in 0..1 {
         let input_buffer = input_buf.clone();
@@ -37,7 +37,7 @@ fn log(input_buf: Arc<Mutex<String>>) -> Vec<thread::JoinHandle<()>> {
         threads.push(join);
     }
 
-    threads
+    Ok(threads)
 }
 
 fn swap_write(
@@ -60,7 +60,7 @@ fn main() -> Result<()> {
 
     let input_buf = Arc::new(Mutex::new(String::new()));
 
-    let threads = log(input_buf.clone());
+    let threads = log(input_buf.clone())?;
 
     let mut count = 0;
 

examples/cursor.rs

@@ -17,36 +17,48 @@ fn goto() -> Result<()> {
 }
 
 /// get the cursor position
-fn pos() {
+fn pos() -> Result<()> {
     // Get the cursor
     let cursor = cursor();
     // get the cursor position.
-    let (x, y) = cursor.pos();
+    let (x, y) = cursor.pos()?;
 
     println!("{} {}", x, y);
+    Ok(())
 }
 
 /// Move the cursor 3 up | demonstration.
-fn move_up() {
+fn move_up() -> Result<()> {
     // Get the cursor
     let mut cursor = cursor();
 
     // Move the cursor to position 3 times to the up in the terminal
-    cursor.move_up(10);
+    cursor.move_up(3)?;
-}
+    Ok(())
-
-/// Move the cursor 3 to the right | demonstration.
-fn move_right() {
-    let mut cursor = cursor();
-    // Move the cursor to position 3 times to the right in the terminal
-    cursor.move_right(3);
 }
 
 /// Move the cursor 3 down | demonstration.
-fn move_down() {
+fn move_down() -> Result<()> {
     let mut cursor = cursor();
     // Move the cursor to position 3 times to the down in the terminal
-    cursor.move_down(3);
+    cursor.move_down(3)?;
+    Ok(())
+}
+
+/// Move the cursor 3 to the right | demonstration.
+fn move_right() -> Result<()> {
+    let mut cursor = cursor();
+    // Move the cursor to position 3 times to the right in the terminal
+    cursor.move_right(3)?;
+    Ok(())
+}
+
+/// Move the cursor 3 left | demonstration.
+fn move_left() -> Result<()> {
+    let mut cursor = cursor();
+    // Move the cursor to position 3 times to the left in the terminal
+    cursor.move_left(3)?;
+    Ok(())
 }
 
 /// Save and reset cursor position | demonstration..

examples/program_examples/snake/src/main.rs

@@ -34,7 +34,7 @@ pub enum Event {
 fn main() -> Result<()> {
     // Print the welcome screen and ask for the map size.
     let crossterm = Crossterm::new();
-    let (map_width, map_height) = ask_for_map_size(crossterm.terminal().terminal_size())?;
+    let (map_width, map_height) = ask_for_map_size(crossterm.terminal().size()?)?;
 
     // Switch screen to the raw mode to avoid printing key presses on the screen
     // and hide the cursor.

examples/terminal.rs

@@ -75,14 +75,15 @@ fn clear_until_new_line() -> Result<()> {
 }
 
 /// Print the the current terminal size | demonstration.
-fn print_terminal_size() {
+fn print_terminal_size() -> Result<()> {
     let terminal = terminal();
 
     // Get terminal size
-    let (width, height) = terminal.terminal_size();
+    let (width, height) = terminal.size()?;
 
     // Print results
     print!("X: {}, y: {}", width, height);
+    Ok(())
 }
 
 /// Set the terminal size to width 10, height: 10 | demonstration.

scripts/test-examples.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+set -ev
+pushd examples/program_examples
+for d in */ ; do
+    pushd "$d"
+    cargo build
+    if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then
+        cargo fmt --all -- --check
+    fi
+    popd
+done
+popd