feat(display-server): add DisplayServer<F: Framebuffer> with protocol, mock adapter, and tests

crates/servers/display-server/src/tests/server.rs

@@ -0,0 +1,75 @@
+use crate::adapters::mock::MockFramebuffer;
+use crate::protocol::{DisplayRequest, DisplayResponse};
+use crate::server::DisplayServer;
+use server_framework::Server;
+
+fn test_server() -> DisplayServer<MockFramebuffer> {
+    DisplayServer::new(MockFramebuffer::new(320, 240))
+}
+
+#[test]
+fn draw_rect_writes_pixels() {
+    let mut server = test_server();
+    let resp = server.handle(DisplayRequest::DrawRect {
+        x: 0,
+        y: 0,
+        w: 4,
+        h: 3,
+        color: 0xFF,
+    });
+    assert_eq!(resp, DisplayResponse::Ok);
+    assert_eq!(server.framebuffer().pixel_count(), 12);
+}
+
+#[test]
+fn clear_resets_pixels() {
+    let mut server = test_server();
+    server.handle(DisplayRequest::DrawRect {
+        x: 0,
+        y: 0,
+        w: 10,
+        h: 10,
+        color: 0xFF,
+    });
+    server.handle(DisplayRequest::Clear { color: 0 });
+    assert_eq!(server.framebuffer().pixel_count(), 0);
+}
+
+#[test]
+fn flush_sets_flag() {
+    let mut server = test_server();
+    assert!(!server.framebuffer().was_flushed());
+    server.handle(DisplayRequest::Flush);
+    assert!(server.framebuffer().was_flushed());
+}
+
+#[test]
+fn get_dimensions_returns_size() {
+    let mut server = test_server();
+    let resp = server.handle(DisplayRequest::GetDimensions);
+    assert_eq!(
+        resp,
+        DisplayResponse::Dimensions {
+            width: 320,
+            height: 240
+        }
+    );
+}
+
+#[test]
+fn draw_rect_correct_pixel_positions() {
+    let mut server = test_server();
+    server.handle(DisplayRequest::DrawRect {
+        x: 5,
+        y: 10,
+        w: 2,
+        h: 2,
+        color: 0xAB,
+    });
+    let fb = server.framebuffer();
+    assert_eq!(fb.pixel_count(), 4);
+    assert_eq!(fb.pixel_at(0), (5, 10, 0xAB));
+    assert_eq!(fb.pixel_at(1), (6, 10, 0xAB));
+    assert_eq!(fb.pixel_at(2), (5, 11, 0xAB));
+    assert_eq!(fb.pixel_at(3), (6, 11, 0xAB));
+}