Test idempotency

sdk/metric/pipeline.go

@@ -90,17 +90,16 @@ func (p *pipeline) addSync(id instrumentID, scope instrumentation.Scope, iSync i
 	p.Lock()
 	defer p.Unlock()
 	if p.seen == nil {
-		p.seen = map[instrumentID]struct{}{}
+		p.seen = make(map[instrumentID]struct{})
 	} else {
 		if _, ok := p.seen[id]; ok {
 			return
 		}
 	}
 	if p.aggregations == nil {
 		p.aggregations = map[instrumentation.Scope][]instrumentSync{
-			scope: {iSync},
+			scope: make([]instrumentSync, 0, 1),
 		}
-		return
 	}
 	p.seen[id] = struct{}{}
 	p.aggregations[scope] = append(p.aggregations[scope], iSync)

sdk/metric/pipeline_test.go

@@ -145,6 +145,26 @@ func TestPipelineConcurrency(t *testing.T) {
 	wg.Wait()
 }
 
+func TestPipelineAddSyncIdempotentcy(t *testing.T) {
+	scope := instrumentation.Scope{Name: "TestPipelineAddSyncIdempotentcy"}
+	const name0 = "i0"
+	id0, i0 := instrumentID{Name: name0}, instrumentSync{name: name0}
+
+	p := newPipeline(resource.Empty(), NewManualReader(), nil)
+	p.addSync(id0, scope, i0)
+
+	assert.Contains(t, p.seen, id0, "id not tracked")
+
+	require.Len(t, p.aggregations[scope], 1, "instrumentSync in pipeline")
+	require.Equal(t, name0, p.aggregations[scope][0].name, "wrong instrumentSync added")
+
+	i1 := instrumentSync{name: "i1"}
+	p.addSync(id0, scope, i1)
+
+	require.Len(t, p.aggregations[scope], 1, "additional instrumentSync in pipeline")
+	assert.Equal(t, name0, p.aggregations[scope][0].name, "instrumentSync modified")
+}
+
 func TestDefaultViewImplicit(t *testing.T) {
 	t.Run("Int64", testDefaultViewImplicit[int64]())
 	t.Run("Float64", testDefaultViewImplicit[float64]())