start building out unit tests

src/term/color.rs

@@ -24,7 +24,7 @@ pub enum AnsiColor {
     White,
 }
 
-#[derive(Debug, Clone, Copy, Default)]
+#[derive(Debug, Clone, Copy, Default, Eq, PartialEq)]
 pub struct RgbColor {
     pub red: u8,
     pub green: u8,
@@ -33,7 +33,7 @@ pub struct RgbColor {
 
 impl RgbColor {}
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
 pub enum ColorAttribute {
     Foreground,
     Background,

src/term/mod.rs

@@ -10,11 +10,19 @@ pub mod color;
 mod csi;
 use self::csi::*;
 
+#[cfg(test)]
+mod test;
+
 /// The response we given when queries for device attributes.
 /// This particular string says "we are a VT102".
 /// TODO: Consider VT220 extended response which can advertise
 /// certain feature sets.
-const DEVICE_IDENT: &[u8] = b"\x1b[?6c";
+pub const DEVICE_IDENT: &[u8] = b"\x1b[?6c";
+
+pub const CSI: &[u8] = b"\x1b[";
+pub const OSC: &[u8] = b"\x1b]";
+pub const ST: &[u8] = b"\x1b\\";
+pub const DCS: &[u8] = b"\x1bP";
 
 bitflags! {
     #[derive(Default)]
@@ -39,7 +47,7 @@ pub enum KeyCode {
     Shift,
 }
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
 pub struct CellAttributes {
     attributes: u16,
     pub foreground: color::ColorAttribute,
@@ -142,12 +150,18 @@ impl Default for CellAttributes {
     }
 }
 
-#[derive(Debug, Clone, Copy, Default)]
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
 pub struct Cell {
     chars: [u8; 8],
     pub attrs: CellAttributes,
 }
 
+impl Default for Cell {
+    fn default() -> Cell {
+        Cell::from_char(' ', &CellAttributes::default())
+    }
+}
+
 impl Cell {
     #[inline]
     pub fn chars(&self) -> &[u8] {
@@ -168,6 +182,12 @@ impl Cell {
     }
 }
 
+impl From<char> for Cell {
+    fn from(c: char) -> Cell {
+        Cell::from_char(c, &CellAttributes::default())
+    }
+}
+
 #[derive(Debug, Clone)]
 pub struct Line {
     pub cells: Vec<Cell>,
@@ -223,6 +243,12 @@ impl Line {
     }
 }
 
+impl<'a> From<&'a str> for Line {
+    fn from(s: &str) -> Line {
+        Line::from_text(s, &CellAttributes::default())
+    }
+}
+
 /// Holds the model of a screen.  This can either be the primary screen
 /// which includes lines of scrollback text, or the alternate screen
 /// which holds no scrollback.  The intent is to have one instance of
@@ -307,6 +333,12 @@ impl Screen {
         self.lines[line_idx].dirty = false;
     }
 
+    /// Returns a slice over the visible lines in the screen (no scrollback)
+    fn visible_lines(&self) -> &[Line] {
+        let line_idx = self.lines.len() - self.physical_rows;
+        &self.lines[line_idx..line_idx + self.physical_rows]
+    }
+
     /// Set a cell.  the x and y coordinates are relative to the visible screeen
     /// origin.  0,0 is the top left.
     pub fn set_cell(&mut self, x: usize, y: usize, c: char, attr: &CellAttributes) {
@@ -324,13 +356,13 @@ impl Screen {
         let width = cells.len();
         // if the line isn't wide enough, pad it out with the default attributes
         if x >= width {
-            cells.resize(x + 1, Cell::from_char(' ', &CellAttributes::default()));
+            cells.resize(x + 1, Cell::default());
         }
         cells[x] = Cell::from_char(c, attr);
     }
 
     pub fn clear_line(&mut self, y: usize, cols: std::ops::Range<usize>) {
-        let blank = Cell::from_char(' ', &CellAttributes::default());
+        let blank = Cell::default();
         let line_idx = (self.lines.len() - self.physical_rows) + y;
         let line = self.line_mut(line_idx);
         let max_col = line.cells.len();
@@ -881,13 +913,23 @@ impl vte::Perform for TerminalState {
                 }
                 CSIAction::DeleteLines(n) => {
                     let top = self.cursor_y;
-                    println!("execute delete {} lines with scroll up {} {}", n, top, top+n);
-                    self.screen_mut().scroll_up(top, top+n, n);
+                    println!(
+                        "execute delete {} lines with scroll up {} {}",
+                        n,
+                        top,
+                        top + n
+                    );
+                    self.screen_mut().scroll_up(top, top + n, n);
                 }
                 CSIAction::InsertLines(n) => {
                     let top = self.cursor_y;
-                    println!("execute insert {} lines with scroll down {} {}", n, top, top+n);
-                    self.screen_mut().scroll_down(top, top+n, n);
+                    println!(
+                        "execute insert {} lines with scroll down {} {}",
+                        n,
+                        top,
+                        top + n
+                    );
+                    self.screen_mut().scroll_down(top, top + n, n);
                 }
             }
         }

src/term/test/mod.rs

@@ -0,0 +1,121 @@
+//! Various tests of the terminal model and escape sequence
+//! processing routines.
+
+use super::*;
+
+fn set_mode(term: &mut Terminal, mode: &str, enable: bool) {
+    term.advance_bytes(CSI);
+    term.advance_bytes(mode);
+    term.advance_bytes(if enable { b"h" } else { b"l" });
+}
+
+fn cup(term: &mut Terminal, row: isize, col: isize) {
+    term.advance_bytes(CSI);
+    term.advance_bytes(format!("{};{}H", row, col));
+}
+
+fn erase_in_display(term: &mut Terminal, erase: DisplayErase) {
+    term.advance_bytes(CSI);
+    let num = match erase {
+        DisplayErase::Below => 0,
+        DisplayErase::Above => 1,
+        DisplayErase::All => 2,
+        DisplayErase::SavedLines => 3,
+    };
+    term.advance_bytes(format!("{}J", num));
+}
+
+fn erase_in_line(term: &mut Terminal, erase: LineErase) {
+    term.advance_bytes(CSI);
+    let num = match erase {
+        LineErase::ToRight => 0,
+        LineErase::ToLeft => 1,
+        LineErase::All => 2,
+    };
+    term.advance_bytes(format!("{}K", num));
+}
+
+/// Asserts that the visible lines of the terminal have the
+/// same cell contents.  The cells must exactly match.
+fn assert_visible_lines(term: &Terminal, expect_lines: &[Line]) {
+    let screen = term.screen();
+    let lines = screen.visible_lines();
+
+    assert!(
+        lines.len() == expect_lines.len(),
+        "expectation has wrong number of lines"
+    );
+
+    let mut expect_iter = expect_lines.iter();
+
+    for (idx, line) in lines.iter().enumerate() {
+        let expect = expect_iter.next().unwrap();
+
+        assert!(
+            expect.cells == line.cells,
+            "line {} was {:?} but expected {:?}",
+            idx,
+            line.cells,
+            expect.cells
+        );
+    }
+}
+
+/// Asserts that the visible lines of the terminal have the
+/// same character contents as the expected lines.
+/// The other cell attributes are not compared; this is
+/// a convenience for writing visually understandable tests.
+fn assert_visible_contents(term: &Terminal, expect_lines: &[&str]) {
+    let screen = term.screen();
+    let lines = screen.visible_lines();
+
+    assert!(
+        lines.len() == expect_lines.len(),
+        "expectation has wrong number of lines"
+    );
+
+    let mut expect_iter = expect_lines.iter();
+
+    for (idx, line) in lines.iter().enumerate() {
+        let expect = expect_iter.next().unwrap();
+        let line_str = line.as_str();
+
+        assert!(
+            &line_str == expect,
+            "line {} was {:?} but expected {:?}",
+            idx,
+            line_str,
+            expect
+        );
+    }
+}
+
+#[test]
+fn basic_output() {
+    let mut term = Terminal::new(5, 10, 0);
+
+    cup(&mut term, 2, 2);
+    term.advance_bytes("hello, world!");
+    assert_visible_contents(
+        &term,
+        &[
+            "          ",
+            " hello, wo",
+            "rld!      ",
+            "          ",
+            "          ",
+        ],
+    );
+
+    erase_in_display(&mut term, DisplayErase::Above);
+    assert_visible_contents(
+        &term,
+        &[
+            "          ",
+            "          ",
+            "rld!      ",
+            "          ",
+            "          ",
+        ],
+    );
+}