From 9af9c9eb66062bec5618c2198952c2f9c5c64769 Mon Sep 17 00:00:00 2001
From: Alex Boten <aboten@lightstep.com>
Date: Fri, 10 Sep 2021 09:02:04 -0700
Subject: [PATCH] adding NewNoopMeterProvider to follow trace api

---
 metric/global/metric_test.go       |  2 +-
 metric/{metric_noop.go => noop.go} | 13 +++++++++---
 metric/noop_test.go                | 34 ++++++++++++++++++++++++++++++
 3 files changed, 45 insertions(+), 4 deletions(-)
 rename metric/{metric_noop.go => noop.go} (78%)
 create mode 100644 metric/noop_test.go

diff --git a/metric/global/metric_test.go b/metric/global/metric_test.go
index 8f6000245ad..9eee03f9895 100644
--- a/metric/global/metric_test.go
+++ b/metric/global/metric_test.go
@@ -30,7 +30,7 @@ func (*testMeterProvider) Meter(_ string, _ ...metric.MeterOption) metric.Meter
 
 func TestMultipleGlobalMeterProvider(t *testing.T) {
 	p1 := testMeterProvider{}
-	p2 := metric.NoopMeterProvider{}
+	p2 := metric.NewNoopMeterProvider()
 	SetMeterProvider(&p1)
 	SetMeterProvider(&p2)
 
diff --git a/metric/metric_noop.go b/metric/noop.go
similarity index 78%
rename from metric/metric_noop.go
rename to metric/noop.go
index 30e57b6945b..0259280ad15 100644
--- a/metric/metric_noop.go
+++ b/metric/noop.go
@@ -21,19 +21,26 @@ import (
 	"go.opentelemetry.io/otel/metric/number"
 )
 
-type NoopMeterProvider struct{}
+// NewNoopMeterProvider returns an implementation of MeterProvider that
+// performs no operations. The Meter and Instrument created from the returned
+// MeterProvider also perform no operations.
+func NewNoopMeterProvider() noopMeterProvider {
+	return noopMeterProvider{}
+}
+
+type noopMeterProvider struct{}
 
 type noopInstrument struct{}
 type noopBoundInstrument struct{}
 type NoopSync struct{ noopInstrument }
 type NoopAsync struct{ noopInstrument }
 
-var _ MeterProvider = NoopMeterProvider{}
+var _ MeterProvider = noopMeterProvider{}
 var _ SyncImpl = NoopSync{}
 var _ BoundSyncImpl = noopBoundInstrument{}
 var _ AsyncImpl = NoopAsync{}
 
-func (NoopMeterProvider) Meter(_ string, _ ...MeterOption) Meter {
+func (noopMeterProvider) Meter(_ string, _ ...MeterOption) Meter {
 	return Meter{}
 }
 
diff --git a/metric/noop_test.go b/metric/noop_test.go
new file mode 100644
index 00000000000..e5a7528a217
--- /dev/null
+++ b/metric/noop_test.go
@@ -0,0 +1,34 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package metric
+
+import (
+	"testing"
+)
+
+func TestNewNoopMeterProvider(t *testing.T) {
+	got, want := NewNoopMeterProvider(), noopMeterProvider{}
+	if got != want {
+		t.Errorf("NewNoopMeterProvider() returned %#v, want %#v", got, want)
+	}
+}
+
+func TestNoopMeterProviderMeter(t *testing.T) {
+	mp := NewNoopMeterProvider()
+	got, want := mp.Meter(""), Meter{}
+	if got != want {
+		t.Errorf("noopMeterProvider.Meter() returned %#v, want %#v", got, want)
+	}
+}