fix: Correctly handle a wrapper name without a wrapper version. (#499)

BEGIN_COMMIT_OVERRIDE
fix: Correctly handle a wrapper name without a wrapper version.
chore: Add support for the wrapper contract tests.
END_COMMIT_OVERRIDE

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Properly handle wrapper name without version in HTTP headers and add
wrapper config/capability to contract tests.
> 
> - **Common HTTP properties**:
> - `HttpPropertiesBuilder::Build`: Set `X-LaunchDarkly-Wrapper` to just
`wrapper_name` when `wrapper_version` is empty; otherwise
`name/version`.
> - **Contract tests**:
> - **Data model**: Add `ConfigWrapper` and optional
`configuration.wrapper` in `ConfigParams`.
> - **Entity managers**: Use
`HttpProperties().WrapperName/WrapperVersion` when
`configuration.wrapper` provided (client and server).
> - **Capabilities**: Advertise `"wrapper"` in client and server test
services.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
2154d6e. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: kinyoklion

contract-tests/client-contract-tests/src/entity_manager.cpp

@@ -146,6 +146,15 @@ std::optional<std::string> EntityManager::create(ConfigParams const& in) {
         config_builder.HttpProperties().Tls(std::move(builder));
     }
 
+    if (in.wrapper) {
+        if (!in.wrapper->name.empty()) {
+            config_builder.HttpProperties().WrapperName(in.wrapper->name);
+        }
+        if (!in.wrapper->version.empty()) {
+            config_builder.HttpProperties().WrapperVersion(in.wrapper->version);
+        }
+    }
+
     auto config = config_builder.Build();
     if (!config) {
         LD_LOG(logger_, LogLevel::kWarn)

contract-tests/client-contract-tests/src/main.cpp

@@ -47,6 +47,7 @@ int main(int argc, char* argv[]) {
         srv.add_capability("tls:skip-verify-peer");
         srv.add_capability("tls:custom-ca");
         srv.add_capability("client-prereq-events");
+        srv.add_capability("wrapper");
         // Proxies are supported only with CURL networking.
 #ifdef LD_CURL_NETWORKING
         srv.add_capability("http-proxy");

contract-tests/data-model/include/data_model/data_model.hpp

@@ -143,6 +143,13 @@ struct ConfigHooksParams {
 
 NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(ConfigHooksParams, hooks);
 
+struct ConfigWrapper {
+    std::string name;
+    std::string version;
+};
+
+NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(ConfigWrapper, name, version);
+
 struct ConfigParams {
     std::string credential;
     std::optional<uint32_t> startWaitTimeMs;
@@ -156,6 +163,7 @@ struct ConfigParams {
     std::optional<ConfigTLSParams> tls;
     std::optional<ConfigProxyParams> proxy;
     std::optional<ConfigHooksParams> hooks;
+    std::optional<ConfigWrapper> wrapper;
 };
 
 NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(ConfigParams,
@@ -170,7 +178,8 @@ NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(ConfigParams,
                                                 tags,
                                                 tls,
                                                 proxy,
-                                                hooks);
+                                                hooks,
+                                                wrapper);
 
 struct ContextSingleParams {
     std::optional<std::string> kind;

contract-tests/server-contract-tests/src/entity_manager.cpp

@@ -145,6 +145,15 @@ std::optional<std::string> EntityManager::create(ConfigParams const& in) {
         }
     }
 
+    if (in.wrapper) {
+        if (!in.wrapper->name.empty()) {
+            config_builder.HttpProperties().WrapperName(in.wrapper->name);
+        }
+        if (!in.wrapper->version.empty()) {
+            config_builder.HttpProperties().WrapperVersion(in.wrapper->version);
+        }
+    }
+
     auto config = config_builder.Build();
     if (!config) {
         LD_LOG(logger_, LogLevel::kWarn)

contract-tests/server-contract-tests/src/main.cpp

@@ -50,6 +50,7 @@ int main(int argc, char* argv[]) {
         srv.add_capability("client-prereq-events");
         srv.add_capability("evaluation-hooks");
         srv.add_capability("track-hooks");
+        srv.add_capability("wrapper");
 
         net::signal_set signals{ioc, SIGINT, SIGTERM};
 

libs/common/src/config/http_properties_builder.cpp

@@ -133,8 +133,12 @@ template <typename SDK>
 built::HttpProperties HttpPropertiesBuilder<SDK>::Build() const {
     if (!wrapper_name_.empty()) {
         std::map<std::string, std::string> headers_with_wrapper(base_headers_);
-        headers_with_wrapper["X-LaunchDarkly-Wrapper"] =
-            wrapper_name_ + "/" + wrapper_version_;
+        if (wrapper_version_.empty()) {
+            headers_with_wrapper["X-LaunchDarkly-Wrapper"] = wrapper_name_;
+        } else {
+            headers_with_wrapper["X-LaunchDarkly-Wrapper"] =
+                wrapper_name_ + "/" + wrapper_version_;
+        }
         return {connect_timeout_,  read_timeout_,        write_timeout_,
                 response_timeout_, headers_with_wrapper, tls_.Build(), proxy_};
     }