add health_metric_collection implementation

Add the interface and implementation for health_metric_collection which
encapsulates various health_metrics.
This change is in relation to following design and D-Bus interface
update -
https://gerrit.openbmc.org/c/openbmc/docs/+/64917
https://gerrit.openbmc.org/c/openbmc/phosphor-dbus-interfaces/+/64914

Add test_health_metric_collection gtest for unit testing.

Change-Id: Ia0b9fbc6bec4850735c7eb74dcd5c40fc47c568c
Signed-off-by: Jagpal Singh Gill <paligill@gmail.com>
diff --git a/test/meson.build b/test/meson.build
index f240bc0..c4f8993 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -54,3 +54,23 @@
         include_directories: '../',
     )
 )
+
+test(
+    'test_health_metric_collection',
+    executable(
+        'test_health_metric_collection',
+        'test_health_metric_collection.cpp',
+        '../health_metric_collection.cpp',
+        '../health_metric.cpp',
+        '../health_metric_config.cpp',
+        '../health_utils.cpp',
+        dependencies: [
+            gtest_dep,
+            gmock_dep,
+            phosphor_logging_dep,
+            phosphor_dbus_interfaces_dep,
+            sdbusplus_dep
+        ],
+        include_directories: '../',
+    )
+)
diff --git a/test/test_health_metric_collection.cpp b/test/test_health_metric_collection.cpp
new file mode 100644
index 0000000..2f4b1b9
--- /dev/null
+++ b/test/test_health_metric_collection.cpp
@@ -0,0 +1,160 @@
+#include "health_metric_collection.hpp"
+
+#include <sdbusplus/test/sdbus_mock.hpp>
+#include <xyz/openbmc_project/Metric/Value/server.hpp>
+
+#include <gtest/gtest.h>
+
+namespace ConfigIntf = phosphor::health::metric::config;
+namespace MetricIntf = phosphor::health::metric;
+namespace CollectionIntf = phosphor::health::metric::collection;
+
+using PathInterface =
+    sdbusplus::common::xyz::openbmc_project::metric::Value::namespace_path;
+using ThresholdIntf =
+    sdbusplus::server::xyz::openbmc_project::common::Threshold;
+using ::testing::Invoke;
+using ::testing::IsNull;
+using ::testing::NotNull;
+using ::testing::StrEq;
+
+class HealthMetricCollectionTest : public ::testing::Test
+{
+  public:
+    sdbusplus::SdBusMock sdbusMock;
+    sdbusplus::bus::bus bus = sdbusplus::get_mocked_new(&sdbusMock);
+
+    static constexpr auto busName = "xyz.openbmc_project.test.HealthMon";
+    static constexpr auto objPath = "/xyz/openbmc_project/sdbusplus/test";
+    const std::string valueInterface =
+        sdbusplus::common::xyz::openbmc_project::metric::Value::interface;
+    const std::string thresholdInterface =
+        sdbusplus::common::xyz::openbmc_project::common::Threshold::interface;
+    ConfigIntf::HealthMetric::map_t configs;
+
+    void SetUp() override
+    {
+        sdbusplus::server::manager_t objManager(bus, objPath);
+        bus.request_name(busName);
+
+        configs = ConfigIntf::getHealthMetricConfigs();
+        EXPECT_THAT(configs.size(), testing::Ge(1));
+        // Update the health metric window size to 1 and path for test purposes
+        for (auto& [key, values] : configs)
+        {
+            for (auto& config : values)
+            {
+                config.windowSize = 1;
+                if (key == MetricIntf::Type::storage &&
+                    config.subType == MetricIntf::SubType::storageReadWrite)
+                {
+                    config.path = "/tmp";
+                }
+            }
+        }
+    }
+
+    void updateThreshold(double value)
+    {
+        for (auto& [key, values] : configs)
+        {
+            for (auto& config : values)
+            {
+                for (auto& threshold : config.thresholds)
+                {
+                    threshold.second.value = value;
+                }
+            }
+        }
+    }
+
+    void createCollection()
+    {
+        std::map<MetricIntf::Type,
+                 std::unique_ptr<CollectionIntf::HealthMetricCollection>>
+            collections;
+        MetricIntf::paths_t bmcPaths = {};
+        for (const auto& [type, collectionConfig] : configs)
+        {
+            collections[type] =
+                std::make_unique<CollectionIntf::HealthMetricCollection>(
+                    bus, type, collectionConfig, bmcPaths);
+            collections[type]->read();
+        }
+    }
+};
+
+TEST_F(HealthMetricCollectionTest, TestCreation)
+{
+    // Change threshold value to 100 to avoid threshold assertion
+    updateThreshold(100);
+
+    EXPECT_CALL(sdbusMock,
+                sd_bus_emit_properties_changed_strv(
+                    IsNull(), NotNull(), StrEq(valueInterface), NotNull()))
+        .WillRepeatedly(Invoke(
+            [&]([[maybe_unused]] sd_bus* bus, [[maybe_unused]] const char* path,
+                [[maybe_unused]] const char* interface, const char** names) {
+        // Test no signal generation for metric init properties
+        const std::set<std::string> metricInitProperties = {"MaxValue",
+                                                            "MinValue", "Unit"};
+        EXPECT_THAT(metricInitProperties,
+                    testing::Not(testing::Contains(names[0])));
+        // Test signal generated for Value property set
+        const std::set<std::string> metricSetProperties = {"Value"};
+        EXPECT_THAT(metricSetProperties, testing::Contains(names[0]));
+        return 0;
+    }));
+
+    EXPECT_CALL(sdbusMock,
+                sd_bus_emit_properties_changed_strv(
+                    IsNull(), NotNull(), StrEq(thresholdInterface), NotNull()))
+        .WillRepeatedly(Invoke(
+            [&]([[maybe_unused]] sd_bus* bus, [[maybe_unused]] const char* path,
+                [[maybe_unused]] const char* interface, const char** names) {
+        // Test no signal generation for threshold init properties
+        const std::set<std::string> thresholdProperties = {"Value", "Asserted"};
+        EXPECT_THAT(thresholdProperties,
+                    testing::Not(testing::Contains(names[0])));
+        return 0;
+    }));
+
+    createCollection();
+}
+
+TEST_F(HealthMetricCollectionTest, TestThresholdAsserted)
+{
+    // Change threshold value to 0 to trigger threshold assertion
+    updateThreshold(0);
+
+    // Test metric value property change
+    EXPECT_CALL(sdbusMock,
+                sd_bus_emit_properties_changed_strv(
+                    IsNull(), NotNull(), StrEq(valueInterface), NotNull()))
+        .WillRepeatedly(Invoke(
+            [&]([[maybe_unused]] sd_bus* bus, [[maybe_unused]] const char* path,
+                [[maybe_unused]] const char* interface, const char** names) {
+        EXPECT_THAT("Value", StrEq(names[0]));
+        return 0;
+    }));
+
+    // Test threshold asserted property change
+    EXPECT_CALL(sdbusMock,
+                sd_bus_emit_properties_changed_strv(
+                    IsNull(), NotNull(), StrEq(thresholdInterface), NotNull()))
+        .WillRepeatedly(Invoke(
+            [&]([[maybe_unused]] sd_bus* bus, [[maybe_unused]] const char* path,
+                [[maybe_unused]] const char* interface, const char** names) {
+        EXPECT_THAT("Asserted", StrEq(names[0]));
+        return 0;
+    }));
+
+    // Test AssertionChanged signal generation
+    EXPECT_CALL(sdbusMock,
+                sd_bus_message_new_signal(IsNull(), NotNull(), NotNull(),
+                                          StrEq(thresholdInterface),
+                                          StrEq("AssertionChanged")))
+        .Times(11);
+
+    createCollection();
+}