1 files changed, 19 insertions, 3 deletions
diff --git a/kamon-core-tests/src/test/scala/kamon/trace/B3SpanCodecSpec.scala b/kamon-core-tests/src/test/scala/kamon/trace/B3SpanCodecSpec.scala
index e6fa283e..f718d806 100644
--- a/kamon-core-tests/src/test/scala/kamon/trace/B3SpanCodecSpec.scala
+++ b/kamon-core-tests/src/test/scala/kamon/trace/B3SpanCodecSpec.scala
@@ -28,15 +28,21 @@ class B3SpanCodecSpec extends WordSpecLike with Matchers with OptionValues with
 
   "The ExtendedB3 SpanContextCodec" should {
     "return a TextMap containing the SpanContext data" in {
-      val context = testContext()
-
-      val textMap = extendedB3Codec.encode(context)
+      val textMap = extendedB3Codec.encode(testContext())
       textMap.get("X-B3-TraceId").value shouldBe "1234"
       textMap.get("X-B3-ParentSpanId").value shouldBe "2222"
       textMap.get("X-B3-SpanId").value shouldBe "4321"
       textMap.get("X-B3-Sampled").value shouldBe "1"
     }
 
+    "do not include the X-B3-ParentSpanId if there is no parent" in {
+      val textMap = extendedB3Codec.encode(testContextWithoutParent())
+      textMap.get("X-B3-TraceId").value shouldBe "1234"
+      textMap.get("X-B3-ParentSpanId") shouldBe empty
+      textMap.get("X-B3-SpanId").value shouldBe "4321"
+      textMap.get("X-B3-Sampled").value shouldBe "1"
+    }
+
 
     "not inject anything if there is no Span in the Context" in {
       val textMap = extendedB3Codec.encode(Context.Empty)
@@ -189,4 +195,14 @@ class B3SpanCodecSpec extends WordSpecLike with Matchers with OptionValues with
     Context.create().withKey(Span.ContextKey, Span.Remote(spanContext))
   }
 
+  def testContextWithoutParent(): Context = {
+    val spanContext = createSpanContext().copy(
+      traceID = Identifier("1234", Array[Byte](1, 2, 3, 4)),
+      spanID = Identifier("4321", Array[Byte](4, 3, 2, 1)),
+      parentID = IdentityProvider.NoIdentifier
+    )
+
+    Context.create().withKey(Span.ContextKey, Span.Remote(spanContext))
+  }
+
 }
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