remove separate name field, single instrument validation

lightstep/sdk/metric/internal/viewstate/viewstate.go

@@ -694,9 +694,6 @@ func viewDescriptor(instrument sdkinstrument.Descriptor, v view.ClauseConfig) sd
 	name := v.Rename(instrument.Name)
 	description := instrument.Description
 	unit := instrument.Unit
-	if v.HasName() {
-		name = v.Name()
-	}
 	if v.Description() != "" {
 		description = v.Description()
 	}

lightstep/sdk/metric/internal/viewstate/viewstate_test.go

@@ -1446,21 +1446,6 @@ func TestRegexpMatch(t *testing.T) {
 	require.NotNil(t, inst2)
 }
 
-func TestSingleInstrumentWarning(t *testing.T) {
-	views := view.New(
-		"test",
-		safePerf,
-		view.WithClause(
-			view.MatchInstrumentNameRegexp(regexp.MustCompile(".*_rate")),
-			view.WithName("fixed"),
-		),
-	)
-
-	_, err := view.Validate(views)
-	require.Error(t, err)
-	require.Contains(t, err.Error(), "multi-instrument view specifies a single name")
-}
-
 func TestDeltaTemporalityMinMaxSumCount(t *testing.T) {
 	views := view.New(
 		"test",

lightstep/sdk/metric/view/clause.go

@@ -37,7 +37,6 @@ type ClauseConfig struct {
 
 	// Properties of the view
 	keys        []attribute.Key // nil implies all keys, []attribute.Key{} implies none
-	name        string
 	renameFunc  RenameInstrumentFunction
 	description string
 	aggregation aggregation.Kind
@@ -112,14 +111,13 @@ func WithKeys(keys []attribute.Key) ClauseOption {
 }
 
 func WithName(name string) ClauseOption {
-	return clauseOptionFunction(func(clause ClauseConfig) ClauseConfig {
-		clause.name = name
-		return clause
+	return WithRenameFunction(func(_ string) string {
+		return name
 	})
 }
 
 // WithRenameFunction provides a function for renaming chosen instruments. This
-// should not be set with WithName().
+// should not be set with WithName() - whichever is applied last will be used.
 func WithRenameFunction(renameFunc RenameInstrumentFunction) ClauseOption {
 	return clauseOptionFunction(func(clause ClauseConfig) ClauseConfig {
 		clause.renameFunc = renameFunc
@@ -148,20 +146,8 @@ func WithAggregatorConfig(acfg aggregator.Config) ClauseOption {
 	})
 }
 
-// IsSingleInstrument is a requirement when HasName().
-func (c *ClauseConfig) IsSingleInstrument() bool {
-	return c.instrumentName != ""
-}
-
-// HasName implies IsSingleInstrument SHOULD be required.
-func (c *ClauseConfig) HasName() bool {
-	return c.name != ""
-}
-
-func (c *ClauseConfig) Name() string {
-	return c.name
-}
-
+// Rename executes the rename function on the name provided. If no rename
+// function was set, the original name is returned.
 func (c *ClauseConfig) Rename(name string) string {
 	if c.renameFunc == nil {
 		return name

lightstep/sdk/metric/view/views.go

@@ -106,11 +106,6 @@ func Validate(v *Views) (*Views, error) {
 	for i := range valid.Clauses {
 		clause := &valid.Clauses[i]
 
-		if !clause.IsSingleInstrument() && clause.HasName() {
-			// Note: no correction, this condition creates conflicts.
-			err = multierr.Append(err, fmt.Errorf("multi-instrument view specifies a single name"))
-		}
-
 		err = v.checkAggregation(err, &clause.aggregation, aggregation.UndefinedKind)
 		err = v.checkAggConfig(err, &clause.acfg)
 
@@ -120,12 +115,6 @@ func Validate(v *Views) (*Views, error) {
 			clause.instrumentNameRegexp = nil
 		}
 
-		if clause.name != "" && clause.renameFunc != nil {
-			err = multierr.Append(err, fmt.Errorf("view has name and rename function"))
-			// Note: prefer the name over the function.
-			clause.renameFunc = nil
-		}
-
 		for i := range clause.keys {
 			if clause.keys[i] == "" {
 				err = multierr.Append(err, fmt.Errorf("view has empty string in keys"))

lightstep/sdk/metric/view/views_test.go

@@ -119,7 +119,7 @@ func TestClauseProperties(t *testing.T) {
 
 	views, err := Validate(views)
 	require.NoError(t, err)
-	require.Equal(t, "longname", views.Clauses[0].Name())
+	require.Equal(t, "longname", views.Clauses[0].Rename(""))
 	require.Equal(t, "very interesting", views.Clauses[1].Description())
 	require.Equal(t, []attribute.Key(nil), views.Clauses[2].Keys())
 	require.Equal(t, []attribute.Key{}, views.Clauses[3].Keys())
@@ -155,17 +155,6 @@ func TestEmptyKeyString(t *testing.T) {
 	require.Contains(t, err.Error(), "view has empty string in keys")
 }
 
-func TestSingleNameConflict(t *testing.T) {
-	views := New("test", safePerf, WithClause(
-		WithName("aha"),
-	))
-
-	_, err := Validate(views)
-
-	require.Error(t, err)
-	require.Contains(t, err.Error(), "multi-instrument view specifies a single name")
-}
-
 func TestStandardTemporality(t *testing.T) {
 	views := New("test", safePerf,
 		WithDefaultAggregationTemporalitySelector(StandardTemporality),