From 449a42da57c0fd743c254a3c7f145fbf67505f06 Mon Sep 17 00:00:00 2001
From: Antonin Amand <antonin.amand@gmail.com>
Date: Fri, 23 Sep 2016 23:40:08 +0200
Subject: [PATCH] Pass options along when creating a span with
 StartSpanFromContext (#114)

---
 gocontext.go       |  6 +++---
 gocontext_test.go  | 28 ++++++++++++++++++++++++++--
 testtracer_test.go | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/gocontext.go b/gocontext.go
index 2745016..222a652 100644
--- a/gocontext.go
+++ b/gocontext.go
@@ -48,10 +48,10 @@ func StartSpanFromContext(ctx context.Context, operationName string, opts ...Sta
 func startSpanFromContextWithTracer(ctx context.Context, tracer Tracer, operationName string, opts ...StartSpanOption) (Span, context.Context) {
 	var span Span
 	if parentSpan := SpanFromContext(ctx); parentSpan != nil {
-		span = tracer.StartSpan(
-			operationName, ChildOf(parentSpan.Context()))
+		opts = append(opts, ChildOf(parentSpan.Context()))
+		span = tracer.StartSpan(operationName, opts...)
 	} else {
-		span = tracer.StartSpan(operationName)
+		span = tracer.StartSpan(operationName, opts...)
 	}
 	return span, ContextWithSpan(ctx, span)
 }
diff --git a/gocontext_test.go b/gocontext_test.go
index 225521e..65c0130 100644
--- a/gocontext_test.go
+++ b/gocontext_test.go
@@ -2,7 +2,9 @@ package opentracing
 
 import (
 	"testing"
+	"time"
 
+	"github.com/stretchr/testify/assert"
 	"golang.org/x/net/context"
 )
 
@@ -38,7 +40,7 @@ func TestStartSpanFromContext(t *testing.T) {
 		if !childSpan.Context().(testSpanContext).HasParent {
 			t.Errorf("Failed to find parent: %v", childSpan)
 		}
-		if childSpan != SpanFromContext(childCtx) {
+		if !childSpan.(testSpan).Equal(SpanFromContext(childCtx)) {
 			t.Errorf("Unable to find child span in context: %v", childCtx)
 		}
 	}
@@ -50,8 +52,30 @@ func TestStartSpanFromContext(t *testing.T) {
 		if childSpan.Context().(testSpanContext).HasParent {
 			t.Errorf("Should not have found parent: %v", childSpan)
 		}
-		if childSpan != SpanFromContext(childCtx) {
+		if !childSpan.(testSpan).Equal(SpanFromContext(childCtx)) {
 			t.Errorf("Unable to find child span in context: %v", childCtx)
 		}
 	}
 }
+
+func TestStartSpanFromContextOptions(t *testing.T) {
+	testTracer := testTracer{}
+
+	// Test options are passed to tracer
+
+	startTime := time.Now().Add(-10 * time.Second) // ten seconds ago
+	span, ctx := startSpanFromContextWithTracer(
+		context.Background(), testTracer, "parent", StartTime(startTime), Tag{"component", "test"})
+
+	assert.Equal(t, "test", span.(testSpan).Tags["component"])
+	assert.Equal(t, startTime, span.(testSpan).StartTime)
+
+	// Test it also works for a child span
+
+	childStartTime := startTime.Add(3 * time.Second)
+	childSpan, _ := startSpanFromContextWithTracer(
+		ctx, testTracer, "child", StartTime(childStartTime))
+
+	assert.Equal(t, childSpan.(testSpan).Tags["component"], nil)
+	assert.Equal(t, childSpan.(testSpan).StartTime, childStartTime)
+}
diff --git a/testtracer_test.go b/testtracer_test.go
index cf0b0b0..7d9106e 100644
--- a/testtracer_test.go
+++ b/testtracer_test.go
@@ -3,6 +3,7 @@ package opentracing
 import (
 	"strconv"
 	"strings"
+	"time"
 )
 
 const testHTTPHeaderPrefix = "testprefix-"
@@ -28,6 +29,35 @@ func (n testSpanContext) ForeachBaggageItem(handler func(k, v string) bool) {}
 type testSpan struct {
 	spanContext   testSpanContext
 	OperationName string
+	StartTime     time.Time
+	Tags          map[string]interface{}
+}
+
+func (n testSpan) Equal(os Span) bool {
+	other, ok := os.(testSpan)
+	if !ok {
+		return false
+	}
+	if n.spanContext != other.spanContext {
+		return false
+	}
+	if n.OperationName != other.OperationName {
+		return false
+	}
+	if !n.StartTime.Equal(other.StartTime) {
+		return false
+	}
+	if len(n.Tags) != len(other.Tags) {
+		return false
+	}
+
+	for k, v := range n.Tags {
+		if ov, ok := other.Tags[k]; !ok || ov != v {
+			return false
+		}
+	}
+
+	return true
 }
 
 // testSpan:
@@ -57,8 +87,11 @@ func (n testTracer) startSpanWithOptions(name string, opts StartSpanOptions) Spa
 	if len(opts.References) > 0 {
 		fakeID = opts.References[0].ReferencedContext.(testSpanContext).FakeID
 	}
+
 	return testSpan{
 		OperationName: name,
+		StartTime:     opts.StartTime,
+		Tags:          opts.Tags,
 		spanContext: testSpanContext{
 			HasParent: len(opts.References) > 0,
 			FakeID:    fakeID,