Add test case for new exception handling code

src/jaegertracing/UDPTransport.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 Uber Technologies, Inc.
+ * Copyright (c) 2017-2018 Uber Technologies, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -115,15 +115,19 @@ int UDPTransport::flush()
     batch.__set_spans(_spanBuffer);
 
     try {
-	    _client->emitBatch(batch);
+        _client->emitBatch(batch);
     } catch (const std::system_error& ex) {
-	std::ostringstream oss;
-	oss << "Could not send span " << ex.what() << ", code=" << ex.code().value();
-	throw Transport::Exception(oss.str(), _spanBuffer.size());
-    } catch (const std::exception &ex) {
-	std::ostringstream oss;
-	oss << "Could not send span " << ex.what();
-	throw Transport::Exception(oss.str(), _spanBuffer.size());
+        std::ostringstream oss;
+        oss << "Could not send span " << ex.what()
+            << ", code=" << ex.code().value();
+        throw Transport::Exception(oss.str(), _spanBuffer.size());
+    } catch (const std::exception& ex) {
+        std::ostringstream oss;
+        oss << "Could not send span " << ex.what();
+        throw Transport::Exception(oss.str(), _spanBuffer.size());
+    } catch (...) {
+        throw Transport::Exception("Could not send span, unknown error",
+                                   _spanBuffer.size());
     }
 
     resetBuffers();

src/jaegertracing/UDPTransport.h

@@ -36,6 +36,12 @@ class UDPTransport : public Transport {
 
     void close() override { _client->close(); }
 
+  protected:
+    void setClient(std::unique_ptr<utils::UDPClient>&& client)
+    {
+        _client = std::move(client);
+    }
+
   private:
     void resetBuffers()
     {

src/jaegertracing/UDPTransportTest.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 Uber Technologies, Inc.
+ * Copyright (c) 2017-2018 Uber Technologies, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,50 @@
 #include "jaegertracing/utils/ErrorUtil.h"
 
 namespace jaegertracing {
+namespace {
+
+class MockUDPClient : public utils::UDPClient {
+  public:
+    enum class ExceptionType { kSystemError, kException, kString };
+
+    MockUDPClient(const net::IPAddress& serverAddr,
+                  int maxPacketSize,
+                  ExceptionType type)
+        : UDPClient(serverAddr, maxPacketSize)
+        , _type(type)
+    {
+    }
+
+  private:
+    void emitBatch(const thrift::Batch& batch) override
+    {
+        switch (_type) {
+        case ExceptionType::kSystemError:
+            throw std::system_error();
+        case ExceptionType::kException:
+            throw std::exception();
+        default:
+            assert(_type == ExceptionType::kString);
+            throw "error";
+        }
+    }
+
+    ExceptionType _type;
+};
+
+class MockUDPTransport : public UDPTransport {
+  public:
+    MockUDPTransport(const net::IPAddress& ip,
+                     int maxPacketSize,
+                     MockUDPClient::ExceptionType type)
+        : UDPTransport(ip, maxPacketSize)
+    {
+        setClient(std::unique_ptr<utils::UDPClient>(
+            new MockUDPClient(ip, maxPacketSize, type)));
+    }
+};
+
+}  // anonymous namespace
 
 TEST(UDPTransport, testManyMessages)
 {
@@ -40,4 +84,25 @@ TEST(UDPTransport, testManyMessages)
     }
 }
 
+TEST(UDPTransport, testExceptions)
+{
+    const auto handle = testutils::TracerUtil::installGlobalTracer();
+    const auto tracer =
+        std::static_pointer_cast<const Tracer>(opentracing::Tracer::Global());
+
+    Span span(tracer);
+    span.SetOperationName("test");
+
+    const MockUDPClient::ExceptionType exceptionTypes[] = {
+        MockUDPClient::ExceptionType::kSystemError,
+        MockUDPClient::ExceptionType::kException,
+        MockUDPClient::ExceptionType::kString
+    };
+    for (auto type : exceptionTypes) {
+        MockUDPTransport sender(net::IPAddress(), 0, type);
+        sender.append(span);
+        ASSERT_THROW(sender.flush(), Transport::Exception);
+    }
+}
+
 }  // namespace jaegertracing

src/jaegertracing/utils/UDPClient.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 Uber Technologies, Inc.
+ * Copyright (c) 2017-2018 Uber Technologies, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -54,7 +54,7 @@ class UDPClient : public agent::thrift::AgentIf {
         if (static_cast<int>(size) > _maxPacketSize) {
             std::ostringstream oss;
             oss << "Data does not fit within one UDP packet"
-                   "; size "
+                   ", size "
                 << size << ", max " << _maxPacketSize << ", spans "
                 << batch.spans.size();
             throw std::logic_error(oss.str());