Pass options to configured TracerProvider (open-telemetry#1329)

Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

CHANGELOG.md

@@ -37,7 +37,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Rename `MergeItererator` to `MergeIterator` in the `go.opentelemetry.io/otel/label` package. (#1244)
 - Move the `go.opentelemetry.io/otel/api/metric/metrictest` package into `go.opentelemetry.io/oteltest` as part of #964. (#1252)
 - Move the `go.opentelemetry.io/otel/api/metric` package into `go.opentelemetry.io/otel/metric` as part of #1303. (#1321)
-- Move the `go.opentelemetry.io/otel/api/metric/registry` package into `go.opentelemetry.io/otel/metric/registry as a part of #1303. (#1316)
+- Move the `go.opentelemetry.io/otel/api/metric/registry` package into `go.opentelemetry.io/otel/metric/registry` as a part of #1303. (#1316)
 - Move the `Number` type (together with related functions) from `go.opentelemetry.io/otel/api/metric` package into `go.opentelemetry.io/otel/metric/number` as a part of #1303. (#1316)
 - The function signature of the Span `AddEvent` method in `go.opentelemetry.io/otel` is updated to no longer take an unused context and instead take a required name and a variable number of `EventOption`s. (#1254)
 - The function signature of the Span `RecordError` method in `go.opentelemetry.io/otel` is updated to no longer take an unused context and instead take a required error value and a variable number of `EventOption`s. (#1254)
@@ -63,6 +63,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 - The `go.opentelemetry.io/otel/api/global` packages global TextMapPropagator now delegates functionality to a globally set delegate for all previously returned propagators. (#1258)
 - Fix condition in `label.Any`. (#1299)
+- Fix global `TracerProvider` to pass options to its configured provider. (#1329)
 
 ## [0.13.0] - 2020-10-08
 

internal/global/trace.go

@@ -84,7 +84,7 @@ func (p *tracerProvider) Tracer(name string, opts ...trace.TracerOption) trace.T
 	defer p.mtx.Unlock()
 
 	if p.delegate != nil {
-		return p.delegate.Tracer(name)
+		return p.delegate.Tracer(name, opts...)
 	}
 
 	t := &tracer{name: name, opts: opts}

internal/global/trace_test.go

@@ -23,6 +23,7 @@ import (
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/internal/global"
 	"go.opentelemetry.io/otel/oteltest"
+	"go.opentelemetry.io/otel/trace"
 )
 
 func TestTraceWithSDK(t *testing.T) {
@@ -61,3 +62,32 @@ func TestTraceWithSDK(t *testing.T) {
 	assert.ElementsMatch(t, expected, filterNames(sr.Started()))
 	assert.ElementsMatch(t, expected, filterNames(sr.Completed()))
 }
+
+type fnTracerProvider struct {
+	tracer func(string, ...trace.TracerOption) trace.Tracer
+}
+
+func (fn fnTracerProvider) Tracer(instrumentationName string, opts ...trace.TracerOption) trace.Tracer {
+	return fn.tracer(instrumentationName, opts...)
+}
+
+func TestTraceProviderDelegates(t *testing.T) {
+	global.ResetForTest()
+
+	// Retrieve the placeholder TracerProvider.
+	gtp := otel.GetTracerProvider()
+
+	// Configure it with a spy.
+	called := false
+	otel.SetTracerProvider(fnTracerProvider{
+		tracer: func(name string, opts ...trace.TracerOption) trace.Tracer {
+			called = true
+			assert.Equal(t, "abc", name)
+			assert.Equal(t, []trace.TracerOption{trace.WithInstrumentationVersion("xyz")}, opts)
+			return trace.NewNoopTracerProvider().Tracer("")
+		},
+	})
+
+	gtp.Tracer("abc", trace.WithInstrumentationVersion("xyz"))
+	assert.True(t, called, "expected configured TraceProvider to be called")
+}