refactor(streamer): adopt proxy backends and typed statuses

src/testers/mcap_reader_tester.cpp

@@ -15,6 +15,23 @@
 
 namespace {
 
+enum class TesterExitCode : int {
+	Success = 0,
+	OpenError = 2,
+	SchemaError = 3,
+	TopicMismatch = 4,
+	TimestampError = 5,
+	ParseError = 6,
+	FormatMismatch = 7,
+	EmptyPayload = 8,
+	ThresholdError = 9,
+};
+
+[[nodiscard]]
+constexpr int exit_code(TesterExitCode code) {
+	return static_cast<int>(code);
+}
+
 struct Config {
 	std::string input_path{};
 	std::optional<std::string> expected_topic{};
@@ -51,7 +68,7 @@ int main(int argc, char **argv) {
 	const auto open_status = reader.open(config->input_path);
 	if (!open_status.ok()) {
 		spdlog::error("failed to open MCAP file '{}': {}", config->input_path, open_status.message);
-		return 2;
+		return exit_code(TesterExitCode::OpenError);
 	}
 
 	std::uint64_t message_count{0};
@@ -63,7 +80,7 @@ int main(int argc, char **argv) {
 		if (it->schema == nullptr || it->channel == nullptr) {
 			spdlog::error("MCAP message missing schema or channel metadata");
 			reader.close();
-			return 3;
+			return exit_code(TesterExitCode::SchemaError);
 		}
 		if (it->schema->encoding != "protobuf" || it->schema->name != "foxglove.CompressedVideo") {
 			continue;
@@ -71,34 +88,34 @@ int main(int argc, char **argv) {
 		if (it->channel->messageEncoding != "protobuf") {
 			spdlog::error("unexpected MCAP message encoding: {}", it->channel->messageEncoding);
 			reader.close();
-			return 3;
+			return exit_code(TesterExitCode::SchemaError);
 		}
 		if (config->expected_topic && it->channel->topic != *config->expected_topic) {
 			spdlog::error("unexpected topic: expected '{}' got '{}'", *config->expected_topic, it->channel->topic);
 			reader.close();
-			return 4;
+			return exit_code(TesterExitCode::TopicMismatch);
 		}
 		if (saw_log_time && it->message.logTime < previous_log_time) {
 			spdlog::error("non-monotonic logTime detected: {} < {}", it->message.logTime, previous_log_time);
 			reader.close();
-			return 5;
+			return exit_code(TesterExitCode::TimestampError);
 		}
 
 		foxglove::CompressedVideo message{};
 		if (!message.ParseFromArray(it->message.data, static_cast<int>(it->message.dataSize))) {
 			spdlog::error("failed to parse foxglove.CompressedVideo payload");
 			reader.close();
-			return 6;
+			return exit_code(TesterExitCode::ParseError);
 		}
 		if (config->expected_format && message.format() != *config->expected_format) {
 			spdlog::error("unexpected format: expected '{}' got '{}'", *config->expected_format, message.format());
 			reader.close();
-			return 7;
+			return exit_code(TesterExitCode::FormatMismatch);
 		}
 		if (message.data().empty()) {
 			spdlog::error("compressed video payload is empty");
 			reader.close();
-			return 8;
+			return exit_code(TesterExitCode::EmptyPayload);
 		}
 
 		previous_log_time = it->message.logTime;
@@ -110,9 +127,9 @@ int main(int argc, char **argv) {
 
 	if (message_count < config->min_messages) {
 		spdlog::error("message threshold not met: {} < {}", message_count, config->min_messages);
-		return 9;
+		return exit_code(TesterExitCode::ThresholdError);
 	}
 
 	spdlog::info("validated {} foxglove.CompressedVideo MCAP messages", message_count);
-	return 0;
+	return exit_code(TesterExitCode::Success);
 }