barebones test harness based on mgba-test-runner from agb-rs (#212)

* barebones test harness based on mgba-test-runner from agb-rs

* mgba-test-runner needs libelf

* fix warning spam on non-gba

* test as_u32_slice as well

---------

Co-authored-by: lif <>

Author: lifning

.github/workflows/ci-builds.yml

@@ -15,7 +15,7 @@ jobs:
       - uses: actions/checkout@v2
 
       - name: Install Apt Dependencies
-        run: sudo apt-get update && sudo apt-get install binutils-arm-none-eabi
+        run: sudo apt-get update && sudo apt-get install binutils-arm-none-eabi libelf-dev
 
       - uses: actions-rs/toolchain@v1
         with:
@@ -39,3 +39,19 @@ jobs:
           toolchain: ${{ matrix.rust.toolchain }}
           command: check
           args: --no-default-features
+
+      - name: Install mgba-test-runner
+        uses: actions-rs/cargo@v1
+        with:
+          toolchain: ${{ matrix.rust.toolchain }}
+          command: install
+          # newer revisions don't build on aarch64, at least, because of a c_char mishap
+          args: --git https://github.com/agbrs/agb --rev a7f9fdf01118a7a77d4dcf72f2b74a1961458b36 mgba-test-runner
+
+      - name: Run unit tests
+        uses: actions-rs/cargo@v1
+        env:
+          CARGO_TARGET_THUMBV4T_NONE_EABI_RUNNER: mgba-test-runner
+        with:
+          toolchain: ${{ matrix.rust.toolchain }}
+          command: test

src/lib.rs

@@ -5,6 +5,10 @@
 #![allow(clippy::let_and_return)]
 #![allow(clippy::result_unit_err)]
 #![warn(clippy::missing_inline_in_public_items)]
+#![cfg_attr(test, feature(custom_test_frameworks))]
+#![cfg_attr(test, test_runner(test_harness::test_runner))]
+#![cfg_attr(test, no_main)]
+#![cfg_attr(test, reexport_test_harness_main = "test_main")]
 
 //! A crate for GBA development.
 //!
@@ -174,3 +178,130 @@ macro_rules! include_aligned_bytes {
     Align4(*include_bytes!($file))
   }};
 }
+
+#[cfg(test)]
+mod test_harness {
+  use crate::prelude::*;
+  use crate::{bios, mem, mgba};
+  use core::fmt::Write;
+
+  #[panic_handler]
+  fn panic(info: &core::panic::PanicInfo) -> ! {
+    DISPSTAT.write(DisplayStatus::new().with_irq_vblank(true));
+    BG_PALETTE.index(0).write(Color::from_rgb(25, 10, 5));
+    IE.write(IrqBits::VBLANK);
+    IME.write(true);
+    VBlankIntrWait();
+    VBlankIntrWait();
+    VBlankIntrWait();
+
+    // the Fatal one kills emulation after one line / 256 bytes
+    // so emit all the information as Error first
+    if let Ok(mut log) =
+      mgba::MgbaBufferedLogger::try_new(mgba::MgbaMessageLevel::Error)
+    {
+      writeln!(log, "[failed]").ok();
+      write!(log, "{}", info).ok();
+    }
+
+    if let Ok(mut log) =
+      mgba::MgbaBufferedLogger::try_new(mgba::MgbaMessageLevel::Fatal)
+    {
+      if let Some(loc) = info.location() {
+        write!(log, "panic at {loc}! see mgba error log for details.").ok();
+      } else {
+        write!(log, "panic! see mgba error log for details.").ok();
+      }
+    }
+
+    IE.write(IrqBits::new());
+    bios::IntrWait(true, IrqBits::new());
+    loop {}
+  }
+
+  pub(crate) trait UnitTest {
+    fn run(&self);
+  }
+
+  impl<T: Fn()> UnitTest for T {
+    fn run(&self) {
+      if let Ok(mut log) =
+        mgba::MgbaBufferedLogger::try_new(mgba::MgbaMessageLevel::Info)
+      {
+        write!(log, "{}...", core::any::type_name::<T>()).ok();
+      }
+
+      self();
+
+      if let Ok(mut log) =
+        mgba::MgbaBufferedLogger::try_new(mgba::MgbaMessageLevel::Info)
+      {
+        writeln!(log, "[ok]").ok();
+      }
+    }
+  }
+
+  pub(crate) fn test_runner(tests: &[&dyn UnitTest]) {
+    if let Ok(mut log) =
+      mgba::MgbaBufferedLogger::try_new(mgba::MgbaMessageLevel::Info)
+    {
+      write!(log, "Running {} tests", tests.len()).ok();
+    }
+
+    for test in tests {
+      test.run();
+    }
+    if let Ok(mut log) =
+      mgba::MgbaBufferedLogger::try_new(mgba::MgbaMessageLevel::Info)
+    {
+      write!(log, "Tests finished successfully").ok();
+    }
+  }
+
+  #[no_mangle]
+  extern "C" fn main() {
+    DISPCNT.write(DisplayControl::new().with_video_mode(VideoMode::_0));
+    BG_PALETTE.index(0).write(Color::new());
+
+    crate::test_main();
+
+    BG_PALETTE.index(0).write(Color::from_rgb(5, 15, 25));
+    BG_PALETTE.index(1).write(Color::new());
+    BG0CNT
+      .write(BackgroundControl::new().with_charblock(0).with_screenblock(31));
+    DISPCNT.write(
+      DisplayControl::new().with_video_mode(VideoMode::_0).with_show_bg0(true),
+    );
+
+    // some niceties for people without mgba-test-runner
+    let tsb = TEXT_SCREENBLOCKS.get_frame(31).unwrap();
+    unsafe {
+      mem::set_u32x80_unchecked(
+        tsb.into_block::<1024>().as_mut_ptr().cast(),
+        0,
+        12,
+      );
+    }
+    Cga8x8Thick.bitunpack_4bpp(CHARBLOCK0_4BPP.as_region(), 0);
+
+    let row = tsb.get_row(9).unwrap().iter().skip(6);
+    for (addr, ch) in row.zip(b"all tests passed!") {
+      addr.write(TextEntry::new().with_tile(*ch as u16));
+    }
+
+    DISPSTAT.write(DisplayStatus::new());
+    bios::IntrWait(true, IrqBits::new());
+  }
+}
+
+#[cfg(test)]
+mod test {
+  use super::Align4;
+
+  #[test_case]
+  fn align4_as_u16_u32_slice() {
+    let a = Align4([0u8, 1u8, 2u8, 3u8]);
+    assert_eq!(a.as_u16_slice(), &[0x100_u16.to_le(), 0x302_u16.to_le()]);
+    assert_eq!(a.as_u32_slice(), &[0x3020100_u32.to_le()]);
+  }
+}

src/mem.rs

@@ -1,3 +1,5 @@
+#![cfg_attr(not(feature = "on_gba"), allow(unused_variables))]
+
 use crate::macros::on_gba_or_unimplemented;
 
 /// Copies `u8` at a time between exclusive regions.