feat: wire FDv2 into v3 contract tests, with CI

.github/workflows/server.yml

@@ -36,6 +36,27 @@ jobs:
           test_service_port: ${{ env.TEST_SERVICE_PORT }}
           token: ${{ secrets.GITHUB_TOKEN }}
 
+  contract-tests-fdv2:
+    runs-on: ubuntu-22.04
+    env:
+      TEST_SERVICE_PORT: 8123
+      TEST_SERVICE_BINARY: ./build/contract-tests/server-contract-tests/server-tests
+      SUPPRESSION_FILE: contract-tests/server-contract-tests/test-suppressions-fdv2.txt
+    steps:
+      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955
+      - uses: ./.github/actions/ci
+        with:
+          cmake_target: server-tests
+          run_tests: false
+      - name: 'Launch test service as background task'
+        run: $TEST_SERVICE_BINARY $TEST_SERVICE_PORT 2>&1 &
+      - name: 'Run v3 SDK test harness'
+        run: |
+          curl -s https://raw.githubusercontent.com/launchdarkly/sdk-test-harness/v3.0.0-alpha.3/downloader/run.sh \
+            | VERSION=v3.0.0-alpha.3 \
+              PARAMS="-url http://localhost:$TEST_SERVICE_PORT -debug -stop-service-at-end -skip-from=$SUPPRESSION_FILE" \
+              sh
+
   contract-tests-curl:
     runs-on: ubuntu-22.04
     env:
@@ -59,6 +80,28 @@ jobs:
           test_service_port: ${{ env.TEST_SERVICE_PORT }}
           token: ${{ secrets.GITHUB_TOKEN }}
 
+  contract-tests-fdv2-curl:
+    runs-on: ubuntu-22.04
+    env:
+      TEST_SERVICE_PORT: 8123
+      TEST_SERVICE_BINARY: ./build/contract-tests/server-contract-tests/server-tests
+      SUPPRESSION_FILE: contract-tests/server-contract-tests/test-suppressions-fdv2.txt
+    steps:
+      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955
+      - uses: ./.github/actions/ci
+        with:
+          cmake_target: server-tests
+          run_tests: false
+          use_curl: true
+      - name: 'Launch test service as background task'
+        run: $TEST_SERVICE_BINARY $TEST_SERVICE_PORT 2>&1 &
+      - name: 'Run v3 SDK test harness'
+        run: |
+          curl -s https://raw.githubusercontent.com/launchdarkly/sdk-test-harness/v3.0.0-alpha.3/downloader/run.sh \
+            | VERSION=v3.0.0-alpha.3 \
+              PARAMS="-url http://localhost:$TEST_SERVICE_PORT -debug -stop-service-at-end -skip-from=$SUPPRESSION_FILE" \
+              sh
+
   build-test-server:
     runs-on: ubuntu-22.04
     steps:

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

@@ -113,11 +113,7 @@ NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(ConfigTags,
                                                 applicationId,
                                                 applicationVersion);
 
-enum class HookStage {
-    BeforeEvaluation,
-    AfterEvaluation,
-    AfterTrack
-};
+enum class HookStage { BeforeEvaluation, AfterEvaluation, AfterTrack };
 
 NLOHMANN_JSON_SERIALIZE_ENUM(HookStage,
                              {{HookStage::BeforeEvaluation, "beforeEvaluation"},
@@ -127,7 +123,10 @@ NLOHMANN_JSON_SERIALIZE_ENUM(HookStage,
 struct ConfigHookInstance {
     std::string name;
     std::string callbackUri;
-    std::optional<std::unordered_map<std::string, std::unordered_map<std::string, nlohmann::json>>> data;
+    std::optional<
+        std::unordered_map<std::string,
+                           std::unordered_map<std::string, nlohmann::json>>>
+        data;
     std::optional<std::unordered_map<std::string, std::string>> errors;
 };
 
@@ -150,6 +149,35 @@ struct ConfigWrapper {
 
 NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(ConfigWrapper, name, version);
 
+struct ConfigDataSynchronizerParams {
+    std::optional<ConfigStreamingParams> streaming;
+    std::optional<ConfigPollingParams> polling;
+};
+
+NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(ConfigDataSynchronizerParams,
+                                                streaming,
+                                                polling);
+
+struct ConfigDataInitializerParams {
+    std::optional<ConfigPollingParams> polling;
+};
+
+NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(ConfigDataInitializerParams,
+                                                polling);
+
+struct ConfigDataSystemParams {
+    std::optional<std::vector<ConfigDataInitializerParams>> initializers;
+    std::optional<std::vector<ConfigDataSynchronizerParams>> synchronizers;
+    std::optional<ConfigPollingParams> fdv1Fallback;
+    std::optional<std::string> payloadFilter;
+};
+
+NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(ConfigDataSystemParams,
+                                                initializers,
+                                                synchronizers,
+                                                fdv1Fallback,
+                                                payloadFilter);
+
 struct ConfigBigSegmentsParams {
     std::string callbackUri;
     std::optional<uint32_t> userCacheSize;
@@ -171,6 +199,7 @@ struct ConfigParams {
     std::optional<bool> initCanFail;
     std::optional<ConfigStreamingParams> streaming;
     std::optional<ConfigPollingParams> polling;
+    std::optional<ConfigDataSystemParams> dataSystem;
     std::optional<ConfigEventParams> events;
     std::optional<ConfigServiceEndpointsParams> serviceEndpoints;
     std::optional<ConfigClientSideParams> clientSide;
@@ -188,6 +217,7 @@ NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(ConfigParams,
                                                 initCanFail,
                                                 streaming,
                                                 polling,
+                                                dataSystem,
                                                 events,
                                                 serviceEndpoints,
                                                 clientSide,

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

@@ -12,48 +12,125 @@
 using launchdarkly::LogLevel;
 using namespace launchdarkly::server_side;
 
-EntityManager::EntityManager(boost::asio::any_io_executor executor,
-                             launchdarkly::Logger& logger)
-    : counter_{0}, executor_{std::move(executor)}, logger_{logger} {}
-
-std::optional<std::string> EntityManager::create(ConfigParams const& in) {
-    std::string id = std::to_string(counter_++);
-
-    auto config_builder = ConfigBuilder(in.credential);
-
-    // The contract test service sets endpoints in a way that is disallowed
-    // for users. Specifically, it may set just 1 of the 3 endpoints, whereas
-    // we require all 3 to be set.
-    //
-    // To avoid that error being detected, we must configure the Endpoints
-    // builder with the 3 default URLs, which we can fetch by just calling Build
-    // on a new builder. That way when the contract tests set just 1 URL,
-    // the others have already been "set" so no error occurs.
-    auto const default_endpoints =
-        *config::builders::EndpointsBuilder().Build();
+namespace {
+
+config::builders::DataSystemBuilder::FDv2 BuildFDv2(
+    ConfigDataSystemParams const& cfg,
+    config::builders::EndpointsBuilder* endpoints) {
+    auto fdv2 = config::builders::DataSystemBuilder::FDv2::Custom();
+
+    if (cfg.synchronizers) {
+        for (auto const& sync : *cfg.synchronizers) {
+            if (sync.streaming) {
+                auto s = decltype(fdv2)::Streaming();
+                if (sync.streaming->baseUri) {
+                    s.BaseUrl(*sync.streaming->baseUri);
+                }
+                if (sync.streaming->initialRetryDelayMs) {
+                    s.InitialReconnectDelay(std::chrono::milliseconds(
+                        *sync.streaming->initialRetryDelayMs));
+                }
+                fdv2.Synchronizer(std::move(s));
+            } else if (sync.polling) {
+                auto p = decltype(fdv2)::Polling();
+                if (sync.polling->baseUri) {
+                    p.BaseUrl(*sync.polling->baseUri);
+                }
+                if (sync.polling->pollIntervalMs) {
+                    p.PollInterval(
+                        std::chrono::duration_cast<std::chrono::seconds>(
+                            std::chrono::milliseconds(
+                                *sync.polling->pollIntervalMs)));
+                }
+                fdv2.Synchronizer(std::move(p));
+            }
+        }
+    }
 
-    auto& endpoints =
-        config_builder.ServiceEndpoints()
-            .EventsBaseUrl(default_endpoints.EventsBaseUrl())
-            .PollingBaseUrl(default_endpoints.PollingBaseUrl())
-            .StreamingBaseUrl(default_endpoints.StreamingBaseUrl());
+    if (cfg.initializers) {
+        for (auto const& init : *cfg.initializers) {
+            if (init.polling) {
+                auto p = decltype(fdv2)::Polling();
+                if (init.polling->baseUri) {
+                    p.BaseUrl(*init.polling->baseUri);
+                }
+                fdv2.Initializer(std::move(p));
+            }
+        }
+    }
 
-    if (in.serviceEndpoints) {
-        if (in.serviceEndpoints->streaming) {
-            endpoints.StreamingBaseUrl(*in.serviceEndpoints->streaming);
+    using FDv2Builder = config::builders::DataSystemBuilder::FDv2;
+    if (cfg.fdv1Fallback) {
+        if (cfg.fdv1Fallback->baseUri) {
+            endpoints->PollingBaseUrl(*cfg.fdv1Fallback->baseUri);
+        } else if (cfg.synchronizers && !cfg.synchronizers->empty()) {
+            // No explicit baseUri: derive from the synchronizers list, matching
+            // the no-fdv1Fallback branch below.
+            ConfigDataSynchronizerParams const* selected = nullptr;
+            for (auto const& sync : *cfg.synchronizers) {
+                if (sync.polling) {
+                    selected = &sync;
+                    break;
+                }
+            }
+            if (!selected) {
+                selected = &cfg.synchronizers->front();
+            }
+            if (selected->polling && selected->polling->baseUri) {
+                endpoints->PollingBaseUrl(*selected->polling->baseUri);
+            } else if (selected->streaming && selected->streaming->baseUri) {
+                endpoints->PollingBaseUrl(*selected->streaming->baseUri);
+            }
         }
-        if (in.serviceEndpoints->polling) {
-            endpoints.PollingBaseUrl(*in.serviceEndpoints->polling);
+        FDv2Builder::FDv1Polling p;
+        if (cfg.fdv1Fallback->pollIntervalMs) {
+            p.PollInterval(std::chrono::duration_cast<std::chrono::seconds>(
+                std::chrono::milliseconds(*cfg.fdv1Fallback->pollIntervalMs)));
         }
-        if (in.serviceEndpoints->events) {
-            endpoints.EventsBaseUrl(*in.serviceEndpoints->events);
+        fdv2.FDv1Fallback(std::move(p));
+    } else if (cfg.synchronizers && !cfg.synchronizers->empty()) {
+        // Derive an FDv1 fallback from the synchronizers list: prefer the
+        // first polling sync, otherwise reuse the first synchronizer's
+        // baseUri. The fallback is always polling. The fallback reads its
+        // URL from the global ServiceEndpoints, so set the polling endpoint
+        // to the selected baseUri.
+        ConfigDataSynchronizerParams const* selected = nullptr;
+        for (auto const& sync : *cfg.synchronizers) {
+            if (sync.polling) {
+                selected = &sync;
+                break;
+            }
         }
+        if (!selected) {
+            selected = &cfg.synchronizers->front();
+        }
+        FDv2Builder::FDv1Polling p;
+        if (selected->polling) {
+            if (selected->polling->baseUri) {
+                endpoints->PollingBaseUrl(*selected->polling->baseUri);
+            }
+            if (selected->polling->pollIntervalMs) {
+                p.PollInterval(std::chrono::duration_cast<std::chrono::seconds>(
+                    std::chrono::milliseconds(
+                        *selected->polling->pollIntervalMs)));
+            }
+        } else if (selected->streaming && selected->streaming->baseUri) {
+            endpoints->PollingBaseUrl(*selected->streaming->baseUri);
+        }
+        fdv2.FDv1Fallback(std::move(p));
     }
+
+    return fdv2;
+}
+
+config::builders::DataSystemBuilder::BackgroundSync BuildBackgroundSync(
+    ConfigParams const& in,
+    config::builders::EndpointsBuilder* endpoints) {
     auto datasystem = config::builders::DataSystemBuilder::BackgroundSync();
 
     if (in.streaming) {
         if (in.streaming->baseUri) {
-            endpoints.StreamingBaseUrl(*in.streaming->baseUri);
+            endpoints->StreamingBaseUrl(*in.streaming->baseUri);
         }
         auto streaming = decltype(datasystem)::Streaming();
         if (in.streaming->initialRetryDelayMs) {
@@ -68,7 +145,7 @@ std::optional<std::string> EntityManager::create(ConfigParams const& in) {
 
     if (in.polling) {
         if (in.polling->baseUri) {
-            endpoints.PollingBaseUrl(*in.polling->baseUri);
+            endpoints->PollingBaseUrl(*in.polling->baseUri);
         }
         if (!in.streaming) {
             auto method = decltype(datasystem)::Polling();
@@ -85,7 +162,55 @@ std::optional<std::string> EntityManager::create(ConfigParams const& in) {
         }
     }
 
-    config_builder.DataSystem().Method(std::move(datasystem));
+    return datasystem;
+}
+
+}  // namespace
+
+EntityManager::EntityManager(boost::asio::any_io_executor executor,
+                             launchdarkly::Logger& logger)
+    : counter_{0}, executor_{std::move(executor)}, logger_{logger} {}
+
+std::optional<std::string> EntityManager::create(ConfigParams const& in) {
+    std::string id = std::to_string(counter_++);
+
+    auto config_builder = ConfigBuilder(in.credential);
+
+    // The contract test service sets endpoints in a way that is disallowed
+    // for users. Specifically, it may set just 1 of the 3 endpoints, whereas
+    // we require all 3 to be set.
+    //
+    // To avoid that error being detected, we must configure the Endpoints
+    // builder with the 3 default URLs, which we can fetch by just calling Build
+    // on a new builder. That way when the contract tests set just 1 URL,
+    // the others have already been "set" so no error occurs.
+    auto const default_endpoints =
+        *config::builders::EndpointsBuilder().Build();
+
+    auto& endpoints =
+        config_builder.ServiceEndpoints()
+            .EventsBaseUrl(default_endpoints.EventsBaseUrl())
+            .PollingBaseUrl(default_endpoints.PollingBaseUrl())
+            .StreamingBaseUrl(default_endpoints.StreamingBaseUrl());
+
+    if (in.serviceEndpoints) {
+        if (in.serviceEndpoints->streaming) {
+            endpoints.StreamingBaseUrl(*in.serviceEndpoints->streaming);
+        }
+        if (in.serviceEndpoints->polling) {
+            endpoints.PollingBaseUrl(*in.serviceEndpoints->polling);
+        }
+        if (in.serviceEndpoints->events) {
+            endpoints.EventsBaseUrl(*in.serviceEndpoints->events);
+        }
+    }
+
+    if (in.dataSystem) {
+        config_builder.DataSystem().Method(
+            BuildFDv2(*in.dataSystem, &endpoints));
+    } else {
+        config_builder.DataSystem().Method(BuildBackgroundSync(in, &endpoints));
+    }
 
     auto& event_config = config_builder.Events();
 

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

@@ -52,6 +52,7 @@ int main(int argc, char* argv[]) {
         srv.add_capability("track-hooks");
         srv.add_capability("wrapper");
         srv.add_capability("instance-id");
+        srv.add_capability("fdv1-fallback");
         srv.add_capability("big-segments");
 
         net::signal_set signals{ioc, SIGINT, SIGTERM};

contract-tests/server-contract-tests/test-suppressions-fdv2.txt

@@ -0,0 +1,8 @@
+# C++ implements TTL-based FDv1 fallback; this scenario tests the older terminal semantics. Tracked in SDK-2527.
+streaming/fdv2/FDv1 fallback directive/directive without FDv1 fallback configured halts the data system
+
+# FDv2 public payload filter API is not exposed by the C++ SDK.
+streaming/requests/URL path is computed correctly/environment_filter_key="encoding_not_necessary"/base URI has no trailing slash/GET
+streaming/requests/URL path is computed correctly/environment_filter_key="encoding_not_necessary"/base URI has a trailing slash/GET
+polling/requests/URL path is computed correctly/environment_filter_key="encoding_not_necessary"/base URI has no trailing slash/GET
+polling/requests/URL path is computed correctly/environment_filter_key="encoding_not_necessary"/base URI has a trailing slash/GET