From b8c769a0bf6ad299e409297b15c6e88558b61340 Mon Sep 17 00:00:00 2001
From: Isaac Hier <isaachier@gmail.com>
Date: Sun, 17 Dec 2017 08:49:23 -0500
Subject: [PATCH] Add language prefix to Jaeger client version tag

Signed-off-by: Isaac Hier <isaachier@gmail.com>
---
 src/jaegertracing/Constants.h.in |  2 +-
 src/jaegertracing/TracerTest.cpp | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/jaegertracing/Constants.h.in b/src/jaegertracing/Constants.h.in
index f6292d1d..c5b90f55 100644
--- a/src/jaegertracing/Constants.h.in
+++ b/src/jaegertracing/Constants.h.in
@@ -21,7 +21,7 @@
 
 namespace jaegertracing {
 
-static constexpr auto kJaegerClientVersion = "@PROJECT_VERSION@";
+static constexpr auto kJaegerClientVersion = "C++-@PROJECT_VERSION@";
 static constexpr auto kJaegerClientVersionTagKey = "jaeger.version";
 static constexpr auto kJaegerDebugHeader = "jaeger-debug-id";
 static constexpr auto kJaegerBaggageHeader = "jaeger-baggage";
diff --git a/src/jaegertracing/TracerTest.cpp b/src/jaegertracing/TracerTest.cpp
index 7d352d98..30290d23 100644
--- a/src/jaegertracing/TracerTest.cpp
+++ b/src/jaegertracing/TracerTest.cpp
@@ -122,6 +122,17 @@ TEST(Tracer, testTracer)
     const auto tracer =
         std::static_pointer_cast<Tracer>(opentracing::Tracer::Global());
 
+    auto tagItr =
+        std::find_if(std::begin(tracer->tags()),
+                     std::end(tracer->tags()),
+                     [](const Tag& tag) {
+                         return tag.key() == kJaegerClientVersionTagKey;
+                     });
+    ASSERT_NE(std::end(tracer->tags()), tagItr);
+    ASSERT_TRUE(tagItr->value().is<const char*>());
+    ASSERT_EQ("C++-",
+        static_cast<std::string>(tagItr->value().get<const char*>()).substr(0, 4));
+
     opentracing::StartSpanOptions options;
     options.tags.push_back({ "tag-key", 1.23 });