tests: add tests for bus

Signed-off-by: Amneesh Singh <natto@weirdnatto.in>

tests/bus.cc

@@ -0,0 +1,45 @@
+#include "bus.hh"
+#include <catch2/catch_test_macros.hpp>
+
+#define TAG "bus"
+
+using namespace matar;
+
+class BusFixture {
+  public:
+    BusFixture()
+      : bus(Memory(std::array<uint8_t, Memory::BIOS_SIZE>(),
+                   std::vector<uint8_t>(Header::HEADER_SIZE))) {}
+
+  protected:
+    Bus bus;
+};
+
+TEST_CASE_METHOD(BusFixture, "Byte", TAG) {
+    CHECK(bus.read_byte(3349) == 0);
+
+    bus.write_byte(3349, 0xEC);
+    CHECK(bus.read_byte(3349) == 0xEC);
+    CHECK(bus.read_word(3349) == 0xEC);
+    CHECK(bus.read_halfword(3349) == 0xEC);
+}
+
+TEST_CASE_METHOD(BusFixture, "Halfword", TAG) {
+    CHECK(bus.read_halfword(33750745) == 0);
+
+    bus.write_halfword(33750745, 0x1A4A);
+    CHECK(bus.read_halfword(33750745) == 0x1A4A);
+    CHECK(bus.read_word(33750745) == 0x1A4A);
+    CHECK(bus.read_byte(33750745) == 0x4A);
+}
+
+TEST_CASE_METHOD(BusFixture, "Word", TAG) {
+    CHECK(bus.read_word(100724276) == 0);
+
+    bus.write_word(100724276, 0x3ACC491D);
+    CHECK(bus.read_word(100724276) == 0x3ACC491D);
+    CHECK(bus.read_halfword(100724276) == 0x491D);
+    CHECK(bus.read_byte(100724276) == 0x1D);
+}
+
+#undef TAG