Include SpanContext information in Context Debug

Author: bantonsson

opentelemetry/src/context.rs

@@ -327,9 +327,19 @@ impl Context {
 
 impl fmt::Debug for Context {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("Context")
-            .field("entries", &self.entries.len())
-            .finish()
+        let mut dbg = f.debug_struct("Context");
+        let mut entries = self.entries.len();
+        #[cfg(feature = "trace")]
+        {
+            if let Some(span) = &self.span {
+                dbg.field("span", &span.span_context());
+                entries += 1;
+            } else {
+                dbg.field("span", &"None");
+            }
+        }
+
+        dbg.field("entries", &entries).finish()
     }
 }
 

opentelemetry/src/trace/context.rs

@@ -32,6 +32,12 @@ pub(crate) struct SynchronizedSpan {
     inner: Option<Mutex<global::BoxedSpan>>,
 }
 
+impl SynchronizedSpan {
+    pub(crate) fn span_context(&self) -> &SpanContext {
+        &self.span_context
+    }
+}
+
 impl From<SpanContext> for SynchronizedSpan {
     fn from(value: SpanContext) -> Self {
         Self {

opentelemetry/src/trace/span_context.rs

@@ -544,6 +544,7 @@ impl SpanContext {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::{trace::TraceContextExt, Context};
 
     #[rustfmt::skip]
     fn trace_id_test_data() -> Vec<(TraceId, &'static str, [u8; 16])> {
@@ -647,4 +648,27 @@ mod tests {
         assert!(trace_state.get("testkey").is_none()); // The original state doesn't change
         assert_eq!(inserted_trace_state.get("testkey").unwrap(), "testvalue"); //
     }
+
+    #[test]
+    fn test_context_span_debug() {
+        let cx = Context::current();
+        assert_eq!(
+            format!("{:?}", cx),
+            "Context { span: \"None\", entries: 0 }"
+        );
+        let cx = Context::current().with_remote_span_context(SpanContext::NONE);
+        assert_eq!(
+            format!("{:?}", cx),
+            "Context { \
+               span: SpanContext { \
+                       trace_id: 00000000000000000000000000000000, \
+                       span_id: 0000000000000000, \
+                       trace_flags: TraceFlags(0), \
+                       is_remote: false, \
+                       trace_state: TraceState(None) \
+                     }, \
+               entries: 1 \
+             }"
+        );
+    }
 }