unit tests

bridge/opencensus/go.mod

@@ -3,6 +3,7 @@ module go.opentelemetry.io/otel/bridge/opencensus
 go 1.18
 
 require (
+	github.com/stretchr/testify v1.7.1
 	go.opencensus.io v0.23.0
 	go.opentelemetry.io/otel v1.10.0
 	go.opentelemetry.io/otel/exporters/prometheus v0.32.0
@@ -15,17 +16,20 @@ require (
 require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/go-logr/logr v1.2.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/prometheus/client_golang v1.13.0 // indirect
 	github.com/prometheus/client_model v0.2.0 // indirect
 	github.com/prometheus/common v0.37.0 // indirect
 	github.com/prometheus/procfs v0.8.0 // indirect
 	golang.org/x/sys v0.0.0-20220919091848-fb04ddd9f9c8 // indirect
 	google.golang.org/protobuf v1.28.1 // indirect
+	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c // indirect
 )
 
 replace go.opentelemetry.io/otel => ../..

bridge/opencensus/go.sum

@@ -148,8 +148,10 @@ github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+o
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/konsorten/go-windows-terminal-sequences v1.0.3/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
@@ -201,6 +203,7 @@ github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UV
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
@@ -473,6 +476,7 @@ google.golang.org/protobuf v1.28.1/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqw
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

bridge/opencensus/metric.go

@@ -24,6 +24,7 @@ import (
 	"go.opencensus.io/metric/metricexport"
 	"go.opencensus.io/metric/metricproducer"
 
+	"go.opentelemetry.io/otel"
 	internal "go.opentelemetry.io/otel/bridge/opencensus/internal/ocmetric"
 	"go.opentelemetry.io/otel/exporters/prometheus"
 	"go.opentelemetry.io/otel/sdk/instrumentation"
@@ -32,6 +33,8 @@ import (
 	"go.opentelemetry.io/otel/sdk/resource"
 )
 
+const scopeName = "go.opentelemetry.io/otel/bridge/opencensus"
+
 // exporter implements the OpenCensus metric Exporter interface using an
 // OpenTelemetry base exporter.
 type exporter struct {
@@ -42,22 +45,25 @@ type exporter struct {
 // NewMetricExporter returns an OpenCensus exporter that exports to an
 // OpenTelemetry (push) exporter.
 func NewMetricExporter(base metric.Exporter, res *resource.Resource) metricexport.Exporter {
-	return &exporter{base: base}
+	return &exporter{base: base, res: res}
 }
 
 // ExportMetrics implements the OpenCensus metric Exporter interface by sending
 // to an OpenTelemetry exporter.
 func (e *exporter) ExportMetrics(ctx context.Context, ocmetrics []*ocmetricdata.Metric) error {
 	otelmetrics, err := internal.ConvertMetrics(ocmetrics)
 	if err != nil {
-		return err
+		otel.Handle(err)
+	}
+	if len(otelmetrics) == 0 {
+		return nil
 	}
 	return e.base.Export(ctx, metricdata.ResourceMetrics{
 		Resource: e.res,
 		ScopeMetrics: []metricdata.ScopeMetrics{
 			{
 				Scope: instrumentation.Scope{
-					Name: "go.opentelemetry.io/otel/bridge/opencensus",
+					Name: scopeName,
 				},
 				Metrics: otelmetrics,
 			},
@@ -84,13 +90,10 @@ func (r *reader) Collect(context.Context) (metricdata.ScopeMetrics, error) {
 		data = append(data, ocProducer.Read()...)
 	}
 	otelmetrics, err := internal.ConvertMetrics(data)
-	if err != nil {
-		return metricdata.ScopeMetrics{}, err
-	}
 	return metricdata.ScopeMetrics{
 		Scope: instrumentation.Scope{
-			Name: "go.opentelemetry.io/otel/bridge/opencensus",
+			Name: scopeName,
 		},
 		Metrics: otelmetrics,
-	}, nil
+	}, err
 }