feat(tracer): add more convenience methods for enterings spans

opentelemetry-sdk/src/trace/tracer.rs

@@ -372,4 +372,223 @@ mod tests {
 
         assert!(!span.span_context().is_sampled());
     }
+
+    #[test]
+    fn in_span_with_context_uses_provided_context() {
+        use crate::trace::{InMemorySpanExporter, SimpleSpanProcessor};
+
+        let exporter = InMemorySpanExporter::default();
+        let tracer_provider = crate::trace::SdkTracerProvider::builder()
+            .with_sampler(Sampler::AlwaysOn)
+            .with_span_processor(SimpleSpanProcessor::new(exporter.clone()))
+            .build();
+        let tracer = tracer_provider.tracer("test");
+
+        // Create a parent context explicitly
+        let parent_span = tracer.start("parent");
+        let parent_trace_id = parent_span.span_context().trace_id();
+        let parent_span_id = parent_span.span_context().span_id();
+        let parent_cx = Context::current_with_span(parent_span);
+
+        // Use in_span_with_context with explicit parent context
+        let mut child_trace_id = None;
+        let mut child_span_id = None;
+        let mut executed = false;
+
+        let returned_value = tracer.in_span_with_context("child-span", &parent_cx, |cx| {
+            let span = cx.span();
+            child_trace_id = Some(span.span_context().trace_id());
+            child_span_id = Some(span.span_context().span_id());
+            executed = true;
+            "test_result"
+        });
+
+        // Verify child span inherited parent's trace_id
+        assert_eq!(child_trace_id, Some(parent_trace_id));
+        // Verify child has a different span_id than parent
+        assert_ne!(child_span_id, Some(parent_span_id));
+        // Verify the closure was executed
+        assert!(executed);
+        // Verify return value is passed through
+        assert_eq!(returned_value, "test_result");
+
+        // End the parent span to export it
+        drop(parent_cx);
+
+        // Verify parent-child relationship through exporter
+        let spans = exporter.get_finished_spans().unwrap();
+        assert_eq!(spans.len(), 2);
+        let parent = spans.iter().find(|s| s.name == "parent").unwrap();
+        let child = spans.iter().find(|s| s.name == "child-span").unwrap();
+        assert_eq!(child.parent_span_id, parent.span_context.span_id());
+        assert_eq!(
+            child.span_context.trace_id(),
+            parent.span_context.trace_id()
+        );
+    }
+
+    #[test]
+    fn in_span_with_builder_uses_current_context() {
+        use crate::trace::{InMemorySpanExporter, SimpleSpanProcessor};
+
+        let exporter = InMemorySpanExporter::default();
+        let tracer_provider = crate::trace::SdkTracerProvider::builder()
+            .with_sampler(Sampler::AlwaysOn)
+            .with_span_processor(SimpleSpanProcessor::new(exporter.clone()))
+            .build();
+        let tracer = tracer_provider.tracer("test");
+
+        // Create a parent span and attach it to the current context
+        let parent_span = tracer.start("parent");
+        let parent_trace_id = parent_span.span_context().trace_id();
+        let parent_span_id = parent_span.span_context().span_id();
+        let _attached = Context::current_with_span(parent_span).attach();
+
+        // Use in_span_with_builder with configured span
+        let mut child_trace_id = None;
+
+        tracer.in_span_with_builder(
+            tracer
+                .span_builder("child")
+                .with_kind(SpanKind::Client)
+                .with_attributes(vec![KeyValue::new("test_key", "test_value")]),
+            |cx| {
+                let span = cx.span();
+                child_trace_id = Some(span.span_context().trace_id());
+            },
+        );
+
+        // Verify child span inherited parent's trace_id
+        assert_eq!(child_trace_id, Some(parent_trace_id));
+
+        // End the attached context to export the parent span
+        drop(_attached);
+
+        // Verify parent-child relationship through exporter
+        let spans = exporter.get_finished_spans().unwrap();
+        assert_eq!(spans.len(), 2);
+        let child = spans.iter().find(|s| s.name == "child").unwrap();
+        assert_eq!(child.parent_span_id, parent_span_id);
+        assert_eq!(child.span_context.trace_id(), parent_trace_id);
+    }
+
+    #[test]
+    fn in_span_with_builder_and_context_uses_provided_context() {
+        use crate::trace::{InMemorySpanExporter, SimpleSpanProcessor};
+
+        let exporter = InMemorySpanExporter::default();
+        let tracer_provider = crate::trace::SdkTracerProvider::builder()
+            .with_sampler(Sampler::AlwaysOn)
+            .with_span_processor(SimpleSpanProcessor::new(exporter.clone()))
+            .build();
+        let tracer = tracer_provider.tracer("test");
+
+        // Create a parent context explicitly
+        let parent_span = tracer.start("parent");
+        let parent_trace_id = parent_span.span_context().trace_id();
+        let parent_span_id = parent_span.span_context().span_id();
+        let parent_cx = Context::current_with_span(parent_span);
+
+        // Use in_span_with_builder_and_context with explicit parent context
+        let mut child_trace_id = None;
+        let mut result = 0;
+
+        let returned_value = tracer.in_span_with_builder_and_context(
+            tracer
+                .span_builder("child")
+                .with_kind(SpanKind::Server)
+                .with_attributes(vec![
+                    KeyValue::new("http.method", "GET"),
+                    KeyValue::new("http.url", "/api/test"),
+                ]),
+            &parent_cx,
+            |cx| {
+                let span = cx.span();
+                child_trace_id = Some(span.span_context().trace_id());
+                result = 42;
+                result
+            },
+        );
+
+        // Verify child span inherited parent's trace_id
+        assert_eq!(child_trace_id, Some(parent_trace_id));
+        // Verify return value is passed through
+        assert_eq!(returned_value, 42);
+        assert_eq!(result, 42);
+
+        // End the parent span to export it
+        drop(parent_cx);
+
+        // Verify parent-child relationship through exporter
+        let spans = exporter.get_finished_spans().unwrap();
+        assert_eq!(spans.len(), 2);
+        let child = spans.iter().find(|s| s.name == "child").unwrap();
+        assert_eq!(child.parent_span_id, parent_span_id);
+        assert_eq!(child.span_context.trace_id(), parent_trace_id);
+    }
+
+    #[test]
+    fn in_span_with_builder_and_context_ignores_active_context() {
+        use crate::trace::{InMemorySpanExporter, SimpleSpanProcessor};
+
+        let exporter = InMemorySpanExporter::default();
+        let tracer_provider = crate::trace::SdkTracerProvider::builder()
+            .with_sampler(Sampler::AlwaysOn)
+            .with_span_processor(SimpleSpanProcessor::new(exporter.clone()))
+            .build();
+        let tracer = tracer_provider.tracer("test");
+
+        // Create an active context with a specific trace context
+        let active_span_context = SpanContext::new(
+            TraceId::from(1u128),
+            SpanId::from(1u64),
+            TraceFlags::SAMPLED,
+            true,
+            Default::default(),
+        );
+        let active_trace_id = active_span_context.trace_id();
+        let active_span_id = active_span_context.span_id();
+        let _attached = Context::current_with_span(TestSpan(active_span_context)).attach();
+
+        // Create a different parent context with a different trace ID to explicitly provide
+        let provided_span_context = SpanContext::new(
+            TraceId::from(2u128),
+            SpanId::from(2u64),
+            TraceFlags::SAMPLED,
+            true,
+            Default::default(),
+        );
+        let provided_trace_id = provided_span_context.trace_id();
+        let provided_span_id = provided_span_context.span_id();
+        let provided_cx = Context::current_with_span(TestSpan(provided_span_context));
+
+        // Ensure the two parents have different trace IDs
+        assert_ne!(active_trace_id, provided_trace_id);
+
+        // Use in_span_with_builder_and_context with explicit parent context
+        let mut child_trace_id = None;
+
+        tracer.in_span_with_builder_and_context(
+            tracer.span_builder("child").with_kind(SpanKind::Internal),
+            &provided_cx,
+            |cx| {
+                let span = cx.span();
+                child_trace_id = Some(span.span_context().trace_id());
+            },
+        );
+
+        // Verify child uses the provided context, NOT the active context
+        assert_eq!(child_trace_id, Some(provided_trace_id));
+        assert_ne!(child_trace_id, Some(active_trace_id));
+
+        // Verify parent-child relationship through exporter
+        let spans = exporter.get_finished_spans().unwrap();
+        assert_eq!(spans.len(), 1);
+        let child = &spans[0];
+        assert_eq!(child.name, "child");
+        assert_eq!(child.parent_span_id, provided_span_id);
+        assert_eq!(child.span_context.trace_id(), provided_trace_id);
+        assert_ne!(child.parent_span_id, active_span_id);
+        assert_ne!(child.span_context.trace_id(), active_trace_id);
+    }
 }

opentelemetry/src/trace/tracer.rs

@@ -207,11 +207,126 @@ pub trait Tracer {
         N: Into<Cow<'static, str>>,
         Self::Span: Send + Sync + 'static,
     {
-        let span = self.start(name);
+        self.in_span_with_builder(self.span_builder(name), f)
+    }
+
+    /// Start a new span with a given parent context and execute the given closure with
+    /// reference to the context in which the span is active.
+    ///
+    /// This method starts a new span as a child of the provided parent context and sets
+    /// it as the active span for the given function. It then executes the body. It ends
+    /// the span before returning the execution result.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use opentelemetry::{global, trace::{Span, Tracer, TraceContextExt}, Context, KeyValue};
+    ///
+    /// fn my_function() {
+    ///     let tracer = global::tracer("my-component");
+    ///
+    ///     // Create a parent context
+    ///     let parent = tracer.start("parent-span");
+    ///     let parent_cx = Context::current_with_span(parent);
+    ///
+    ///     // start an active span with explicit parent context
+    ///     tracer.in_span_with_context("child-span", &parent_cx, |_cx| {
+    ///         // child span is active here
+    ///     })
+    /// }
+    /// ```
+    fn in_span_with_context<T, F, N>(&self, name: N, parent_cx: &Context, f: F) -> T
+    where
+        F: FnOnce(Context) -> T,
+        N: Into<Cow<'static, str>>,
+        Self::Span: Send + Sync + 'static,
+    {
+        self.in_span_with_builder_and_context(self.span_builder(name), parent_cx, f)
+    }
+
+    /// Start a new span from a [`SpanBuilder`] and execute the given closure with
+    /// reference to the context in which the span is active.
+    ///
+    /// This method builds and starts a new span from a [`SpanBuilder`] using the current
+    /// context and sets it as the active span for the given function. It then executes
+    /// the body. It ends the span before returning the execution result.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use opentelemetry::{global, trace::{Span, SpanKind, Tracer}, KeyValue};
+    ///
+    /// fn my_function() {
+    ///     let tracer = global::tracer("my-component");
+    ///
+    ///     // start an active span with span configuration
+    ///     tracer.in_span_with_builder(
+    ///         tracer.span_builder("span-name")
+    ///             .with_kind(SpanKind::Client)
+    ///             .with_attributes(vec![KeyValue::new("key", "value")]),
+    ///         |_cx| {
+    ///             // span is active here with configured attributes
+    ///         }
+    ///     )
+    /// }
+    /// ```
+    fn in_span_with_builder<T, F>(&self, builder: SpanBuilder, f: F) -> T
+    where
+        F: FnOnce(Context) -> T,
+        Self::Span: Send + Sync + 'static,
+    {
+        let span = self.build(builder);
         let cx = Context::current_with_span(span);
         let _guard = cx.clone().attach();
         f(cx)
     }
+
+    /// Start a new span from a [`SpanBuilder`] with a given parent context and execute the
+    /// given closure with reference to the context in which the span is active.
+    ///
+    /// This method builds and starts a new span from a [`SpanBuilder`] as a child of the
+    /// provided parent context and sets it as the active span for the given function. It
+    /// then executes the body. It ends the span before returning the execution result.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use opentelemetry::{global, trace::{Span, SpanKind, Tracer, TraceContextExt}, Context, KeyValue};
+    ///
+    /// fn my_function() {
+    ///     let tracer = global::tracer("my-component");
+    ///
+    ///     // Create a parent context
+    ///     let parent = tracer.start("parent-span");
+    ///     let parent_cx = Context::current_with_span(parent);
+    ///
+    ///     // start an active span with explicit parent context and span configuration
+    ///     tracer.in_span_with_builder_and_context(
+    ///         tracer.span_builder("child-span")
+    ///             .with_kind(SpanKind::Client)
+    ///             .with_attributes(vec![KeyValue::new("key", "value")]),
+    ///         &parent_cx,
+    ///         |_cx| {
+    ///             // child span is active here with configured attributes
+    ///         }
+    ///     )
+    /// }
+    /// ```
+    fn in_span_with_builder_and_context<T, F>(
+        &self,
+        builder: SpanBuilder,
+        parent_cx: &Context,
+        f: F,
+    ) -> T
+    where
+        F: FnOnce(Context) -> T,
+        Self::Span: Send + Sync + 'static,
+    {
+        let span = self.build_with_context(builder, parent_cx);
+        let cx = parent_cx.with_span(span);
+        let _guard = cx.clone().attach();
+        f(cx)
+    }
 }
 
 /// `SpanBuilder` allows span attributes to be configured before the span