feat: add tests for trace-to-profile correlation

* test/test_tracer.cpp

Author: elsa

test/test_tracer.cpp

@@ -1566,6 +1566,32 @@ TEST_CASE("128-bit trace IDs") {
   REQUIRE(*high == trace_id.high);
 }
 
+#ifdef __linux__
+TEST_CASE("correlate full host profiles") {
+  TracerConfig config;
+  config.service = "testsvc";
+  config.collector = std::make_shared<NullCollector>();
+  config.logger = std::make_shared<NullLogger>();
+
+  SECTION("is off by default") {
+    auto finalized_config = finalize_config(config);
+    REQUIRE(finalized_config);
+    Tracer tracer{*finalized_config};
+    REQUIRE(elastic_apm_profiling_correlation_process_storage_v1 == nullptr);
+  }
+
+  SECTION("is available when enabled") {
+    config.correlate_full_host_profiles = true;
+    auto finalized_config = finalize_config(config);
+    REQUIRE(finalized_config);
+    Tracer tracer{*finalized_config};
+    REQUIRE(elastic_apm_profiling_correlation_process_storage_v1 != nullptr);
+    auto span = tracer.create_span();
+    REQUIRE(elastic_apm_profiling_correlation_tls_v1 != nullptr);
+  }
+}
+#endif
+
 TEST_CASE(
     "_dd.p.tid invalid or inconsistent with trace ID results in error tag") {
   struct TestCase {