Add new RomTests and fix small bugs in Rom class

src/app/rom.cc

@@ -143,7 +143,7 @@ absl::Status Rom::LoadAllGraphicsData() {
 
 absl::Status Rom::LoadFromFile(const std::string& filename, bool z3_load) {
   std::string full_filename = std::filesystem::absolute(filename).string();
-  if (full_filename.empty()) {
+  if (filename.empty()) {
     return absl::InvalidArgumentError(
         "Could not load ROM: parameter `filename` is empty.");
   }
@@ -153,7 +153,7 @@ absl::Status Rom::LoadFromFile(const std::string& filename, bool z3_load) {
   // Open file
   std::ifstream file(filename_, std::ios::binary);
   if (!file.is_open()) {
-    return absl::InternalError(
+    return absl::NotFoundError(
         absl::StrCat("Could not open ROM file: ", filename_));
   }
 

src/app/rom.h

@@ -209,14 +209,14 @@ class Rom : public core::ExperimentFlags {
   // Read functions
   absl::StatusOr<uint8_t> ReadByte(int offset) {
     if (offset >= rom_data_.size()) {
-      return absl::InvalidArgumentError("Offset out of range");
+      return absl::FailedPreconditionError("Offset out of range");
     }
     return rom_data_[offset];
   }
 
   absl::StatusOr<uint16_t> ReadWord(int offset) {
     if (offset + 1 >= rom_data_.size()) {
-      return absl::InvalidArgumentError("Offset out of range");
+      return absl::FailedPreconditionError("Offset out of range");
     }
     auto result = (uint16_t)(rom_data_[offset] | (rom_data_[offset + 1] << 8));
     return result;
@@ -228,7 +228,7 @@ class Rom : public core::ExperimentFlags {
 
   absl::StatusOr<uint32_t> ReadLong(int offset) {
     if (offset + 2 >= rom_data_.size()) {
-      return absl::InvalidArgumentError("Offset out of range");
+      return absl::FailedPreconditionError("Offset out of range");
     }
     auto result = (uint32_t)(rom_data_[offset] | (rom_data_[offset + 1] << 8) |
                              (rom_data_[offset + 2] << 16));
@@ -238,7 +238,7 @@ class Rom : public core::ExperimentFlags {
   absl::StatusOr<std::vector<uint8_t>> ReadByteVector(uint32_t offset,
                                                       uint32_t length) {
     if (offset + length > rom_data_.size()) {
-      return absl::InvalidArgumentError("Offset and length out of range");
+      return absl::FailedPreconditionError("Offset and length out of range");
     }
     std::vector<uint8_t> result;
     for (int i = offset; i < offset + length; i++) {

src/test/rom_test.cc

@@ -9,14 +9,19 @@
 
 namespace yaze {
 namespace test {
-using yaze::app::Rom;
+
+const static std::vector<uint8_t> kMockRomData = {
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A,
+    0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15,
+    0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
+};
 
 class RomTest : public ::testing::Test {
  protected:
-  Rom rom_;
+  app::Rom rom_;
 };
 
-TEST_F(RomTest, RomTest) {
+TEST_F(RomTest, Uninitialized) {
   EXPECT_EQ(rom_.size(), 0);
   EXPECT_EQ(rom_.data(), nullptr);
 }
@@ -34,5 +39,41 @@ TEST_F(RomTest, LoadFromFileInvalid) {
   EXPECT_EQ(rom_.data(), nullptr);
 }
 
+TEST_F(RomTest, LoadFromFileEmpty) {
+  EXPECT_THAT(rom_.LoadFromFile(""),
+              StatusIs(absl::StatusCode::kInvalidArgument));
+}
+
+TEST_F(RomTest, ReadByteOk) {
+  EXPECT_OK(rom_.LoadFromBytes(kMockRomData));
+
+  for (size_t i = 0; i < kMockRomData.size(); ++i) {
+    uint8_t byte;
+    ASSERT_OK_AND_ASSIGN(byte, rom_.ReadByte(i));
+    EXPECT_EQ(byte, kMockRomData[i]);
+  }
+}
+
+TEST_F(RomTest, ReadByteInvalid) {
+  EXPECT_THAT(rom_.ReadByte(0).status(),
+              StatusIs(absl::StatusCode::kFailedPrecondition));
+}
+
+TEST_F(RomTest, ReadWordOk) {
+  EXPECT_OK(rom_.LoadFromBytes(kMockRomData));
+
+  for (size_t i = 0; i < kMockRomData.size(); i += 2) {
+    // Little endian
+    EXPECT_THAT(
+        rom_.ReadWord(i),
+        IsOkAndHolds<uint16_t>((kMockRomData[i]) | kMockRomData[i + 1] << 8));
+  }
+}
+
+TEST_F(RomTest, ReadWordInvalid) {
+  EXPECT_THAT(rom_.ReadWord(0).status(),
+              StatusIs(absl::StatusCode::kFailedPrecondition));
+}
+
 }  // namespace test
 }  // namespace yaze