Add tests

api/include/opentelemetry/core/timestamp.h

@@ -47,6 +47,11 @@ class SystemTimestamp
     return nanos_since_epoch_ == other.nanos_since_epoch_;
   }
 
+  bool operator!=(const SystemTimestamp &other) const noexcept
+  {
+    return nanos_since_epoch_ != other.nanos_since_epoch_;
+  }
+
 private:
   int64_t nanos_since_epoch_;
 };
@@ -89,6 +94,11 @@ class SteadyTimestamp
     return nanos_since_epoch_ == other.nanos_since_epoch_;
   }
 
+  bool operator!=(const SteadyTimestamp &other) const noexcept
+  {
+    return nanos_since_epoch_ != other.nanos_since_epoch_;
+  }
+
 private:
   int64_t nanos_since_epoch_;
 };

api/include/opentelemetry/trace/span.h

@@ -43,9 +43,13 @@ struct StartSpanOptions
   // Attributes
   SpanKind kind = SpanKind::kInternal;
 };
-
+/**
+ * StartEndOptions provides options to set properties of a Span when it is
+ * ended.
+ */
 struct EndSpanOptions
 {
+  // Optionally sets the end time of a Span.
   core::SteadyTimestamp end_steady_time;
 };
 
@@ -135,8 +139,13 @@ class Span
   // during creation.
   virtual void UpdateName(nostd::string_view name) noexcept = 0;
 
-  // Mark the end of the Span. Only the timing of the first End call for a given Span will
-  // be recorded, and implementations are free to ignore all further calls.
+  /**
+   * Mark the end of the Span.
+   * Only the timing of the first End call for a given Span will be recorded,
+   * and implementations are free to ignore all further calls.
+   * @param options can be used to manually define span properties like the end
+   * timestamp
+   */
   virtual void End(const EndSpanOptions &options = {}) noexcept = 0;
 
   // TODO

api/test/core/timestamp_test.cc

@@ -24,6 +24,19 @@ TEST(SystemTimestampTest, Construction)
             t2.time_since_epoch());
 }
 
+TEST(SystemTimestampTest, Comparison)
+{
+  SystemTimestamp t1;
+  SystemTimestamp t2;
+  SystemTimestamp t3{std::chrono::nanoseconds{2}};
+
+  EXPECT_EQ(t1, t1);
+  EXPECT_EQ(t1, t2);
+  EXPECT_EQ(t2, t1);
+  EXPECT_NE(t1, t3);
+  EXPECT_NE(t3, t1);
+}
+
 TEST(SteadyTimestampTest, Construction)
 {
   auto now_steady = std::chrono::steady_clock::now();
@@ -36,3 +49,16 @@ TEST(SteadyTimestampTest, Construction)
   EXPECT_EQ(std::chrono::duration_cast<std::chrono::nanoseconds>(now_steady.time_since_epoch()),
             t2.time_since_epoch());
 }
+
+TEST(SteadyTimestampTest, Comparison)
+{
+  SteadyTimestamp t1;
+  SteadyTimestamp t2;
+  SteadyTimestamp t3{std::chrono::nanoseconds{2}};
+
+  EXPECT_EQ(t1, t1);
+  EXPECT_EQ(t1, t2);
+  EXPECT_EQ(t2, t1);
+  EXPECT_NE(t1, t3);
+  EXPECT_NE(t3, t1);
+}

sdk/src/trace/span.cc

@@ -13,7 +13,7 @@ using opentelemetry::core::SystemTimestamp;
 
 namespace
 {
-SystemTimestamp NowOrGiven(const SystemTimestamp &system)
+SystemTimestamp NowOr(const SystemTimestamp &system)
 {
   if (system == SystemTimestamp())
   {
@@ -25,7 +25,7 @@ SystemTimestamp NowOrGiven(const SystemTimestamp &system)
   }
 }
 
-SteadyTimestamp NowOrGiven(const SteadyTimestamp &steady)
+SteadyTimestamp NowOr(const SteadyTimestamp &steady)
 {
   if (steady == SteadyTimestamp())
   {
@@ -52,8 +52,8 @@ Span::Span(std::shared_ptr<Tracer> &&tracer,
   processor_->OnStart(*recordable_);
   recordable_->SetName(name);
 
-  recordable_->SetStartTime(NowOrGiven(options.start_system_time));
-  start_steady_time = NowOrGiven(options.start_steady_time);
+  recordable_->SetStartTime(NowOr(options.start_system_time));
+  start_steady_time = NowOr(options.start_steady_time);
 }
 
 Span::~Span()
@@ -109,9 +109,10 @@ void Span::End(const trace_api::EndSpanOptions &options) noexcept
     return;
   }
 
-  recordable_->SetDuration(
-      std::chrono::steady_clock::time_point(NowOrGiven(options.end_steady_time)) -
-      std::chrono::steady_clock::time_point(start_steady_time));
+  auto end_steady_time = NowOr(options.end_steady_time);
+  recordable_->SetDuration(std::chrono::steady_clock::time_point(end_steady_time) -
+                           std::chrono::steady_clock::time_point(start_steady_time));
+
   processor_->OnEnd(std::move(recordable_));
   recordable_.reset();
 }