enable unit-tests: enable for SensorManager

Enabled unit-tests in general for the project, and more
specifically started with a benign construction test for
the SensorManager object.

Tested: Verified continues to build and link, and unit-test
passes.
Tested: Ran on quanta-q71l board and it behaved as expected.

Change-Id: I4ad9a0c57efd0b9ccc37d26faa0cc1b82026b8d7
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/pid/zone.cpp b/pid/zone.cpp
index 393f6e6..ed8cd0f 100644
--- a/pid/zone.cpp
+++ b/pid/zone.cpp
@@ -211,7 +211,7 @@
 
     for (auto& f : _fanInputs)
     {
-        auto& sensor = _mgr->getSensor(f);
+        auto& sensor = _mgr.getSensor(f);
         ReadReturn r = sensor->read();
         _cachedValuesByName[f] = r.value;
 
@@ -243,7 +243,7 @@
 
     for (auto& t : _thermalInputs)
     {
-        auto& sensor = _mgr->getSensor(t);
+        auto& sensor = _mgr.getSensor(t);
         ReadReturn r = sensor->read();
         int64_t timeout = sensor->GetTimeout();
 
@@ -319,9 +319,9 @@
     }
 }
 
-std::unique_ptr<Sensor>& PIDZone::getSensor(std::string name)
+const std::unique_ptr<Sensor>& PIDZone::getSensor(std::string name)
 {
-    return _mgr->getSensor(name);
+    return _mgr.getSensor(name);
 }
 
 bool PIDZone::manual(bool value)
@@ -344,7 +344,7 @@
 std::map<int64_t, std::shared_ptr<PIDZone>> BuildZones(
             std::map<int64_t, PIDConf>& ZonePids,
             std::map<int64_t, struct zone>& ZoneConfigs,
-            std::shared_ptr<SensorManager> mgr,
+            SensorManager& mgr,
             sdbusplus::bus::bus& ModeControlBus)
 {
     std::map<int64_t, std::shared_ptr<PIDZone>> zones;
@@ -446,7 +446,7 @@
 
 std::map<int64_t, std::shared_ptr<PIDZone>> BuildZonesFromConfig(
             std::string& path,
-            std::shared_ptr<SensorManager> mgr,
+            SensorManager& mgr,
             sdbusplus::bus::bus& ModeControlBus)
 {
     using namespace libconfig;