vga buffer tests

Cargo.toml

@@ -31,4 +31,5 @@ test-args = [
      "-device", "isa-debug-exit,iobase=0xf4,iosize=0x04", "-serial", "stdio",
      "-display", "none"
 ]
-test-success-exit-code = 33         # (0x10 << 1) | 1
+test-success-exit-code = 33         # (0x10 << 1) | 1
+test-timeout = 300          # (in seconds)

src/main.rs

@@ -69,21 +69,17 @@ pub extern "C" fn _start() -> ! {
 // ON CARGO TEST IN SOME CASES. TO FIX REMOVE/COMMENT OUT THE ' panic = "abort" ' 
 // FOR A PROFILE IN THE CARGO.TOML FILE
 #[cfg(test)]
-fn test_runner(tests: &[&dyn Fn()]) {
+pub fn test_runner(tests: &[&dyn Testable]) { // new
     serial_println!("Running {} tests", tests.len());
-    println!("Running {} tests", tests.len());
     for test in tests {
-        test();
+        test.run(); // new
     }
-    //new
     exit_qemu(QemuExitCode::Success);
 }
 
 #[test_case]
 fn trivial_assertion() {
-    serial_print!("trivial assertion... ");
-    assert_eq!(0, 1);
-    serial_println!("[ok]");
+    assert_eq!(1, 1);
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -100,4 +96,19 @@ pub fn exit_qemu(exit_code: QemuExitCode) {
         let mut port = Port::new(0xf4);
         port.write(exit_code as u32);
     }
+}
+
+pub trait Testable {
+    fn run(&self) -> ();
+}
+
+impl<T> Testable for T
+where
+    T: Fn(),
+{
+    fn run(&self) {
+        serial_print!("{}...\t", core::any::type_name::<T>());
+        self();
+        serial_println!("[ok]");
+    }
 }

src/vga_buffer.rs

@@ -168,4 +168,26 @@ macro_rules! println {
 pub fn _print(args: fmt::Arguments) {
     use core::fmt::Write;
     WRITER.lock().write_fmt(args).unwrap();
+}
+
+#[test_case]
+fn test_println_simple() {
+    println!("test_println_simple output");
+}
+
+#[test_case]
+fn test_println_many() {
+    for _ in 0..200 {
+        println!("test_println_many output");
+    }
+}
+
+#[test_case]
+fn test_println_output() {
+    let s = "Some test string that fits on a single line";
+    println!("{}", s);
+    for (i, c) in s.chars().enumerate() {
+        let screen_char = WRITER.lock().buffer.chars[BUFFER_HEIGHT - 2][i].read();
+        assert_eq!(char::from(screen_char.ascii_character), c);
+    }
 }