Create an Inmemory Exporter for test

CHANGELOG.md

@@ -16,7 +16,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ### Added
 
-- Added an in-memory exporter to metrictest to aid testing with a full SDK (#2776)
+- Added an in-memory exporter to metrictest to aid testing with a full SDK. (#2776)
 
 ## [0.29.0] - 2022-04-11
 

sdk/metric/metrictest/config.go

@@ -43,8 +43,8 @@ func (f functionOption) apply(cfg config) config {
 
 // WithTemporalitySelector allows for the use of either cumulative (default) or
 // delta metrics.
-
-// Warning the current SDK does not convert async instruments into delta
+//
+// Warning: the current SDK does not convert async instruments into delta
 // temporality.
 func WithTemporalitySelector(ts aggregation.TemporalitySelector) Option {
 	return functionOption(func(cfg config) config {

sdk/metric/metrictest/exporter.go

@@ -140,7 +140,7 @@ func (e *Exporter) Collect(ctx context.Context) error {
 
 // GetRecords returns all Records found by the SDK.
 func (e *Exporter) GetRecords() []ExportRecord {
-	return e.Records[:]
+	return e.Records
 }
 
 var errNotFound = fmt.Errorf("record not found")
@@ -155,7 +155,7 @@ func (e *Exporter) GetByName(name string) (ExportRecord, error) {
 	return ExportRecord{}, errNotFound
 }
 
-// GetByNameAndAttributes returns the first Record with a matching name and set of Attributes.
+// GetByNameAndAttributes returns the first Record with a matching name and the sub-set of attributes.
 func (e *Exporter) GetByNameAndAttributes(name string, attributes []attribute.KeyValue) (ExportRecord, error) {
 	for _, rec := range e.Records {
 		if rec.InstrumentName == name && subSet(attributes, rec.Attributes) {
@@ -165,7 +165,7 @@ func (e *Exporter) GetByNameAndAttributes(name string, attributes []attribute.Ke
 	return ExportRecord{}, errNotFound
 }
 
-// subSet returns true if A is a subset of B
+// subSet returns true if attributesA is a subset of attributesB.
 func subSet(attributesA, attributesB []attribute.KeyValue) bool {
 	b := attribute.NewSet(attributesB...)
 

sdk/metric/metrictest/exporter_test.go

@@ -40,10 +40,10 @@ func TestSyncInstruments(t *testing.T) {
 		fcnt.Add(ctx, 2)
 
 		err = exp.Collect(context.Background())
-		assert.NoError(t, err)
+		requrie.NoError(t, err)
 
 		out, err := exp.GetByName("fCount")
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		assert.InDelta(t, 2.0, out.Sum.AsFloat64(), 0.0001)
 		assert.Equal(t, aggregation.SumKind, out.AggregationKind)
 	})
@@ -421,5 +421,4 @@ func ExampleExporter_GetByNameAndAttributes() {
 
 	fmt.Println(out.Sum.AsFloat64())
 	// Output: 4
-
 }