Move Scraper test functionality to seperate package

go.mod

@@ -412,6 +412,8 @@ replace github.com/open-telemetry/opentelemetry-collector-contrib/internal/aws/a
 
 replace github.com/open-telemetry/opentelemetry-collector-contrib/internal/stanza => ./internal/stanza
 
+replace github.com/open-telemetry/opentelemetry-collector-contrib/internal/scrapertest => ./internal/scrapertest
+
 replace github.com/open-telemetry/opentelemetry-collector-contrib/internal/docker => ./internal/docker
 
 replace github.com/open-telemetry/opentelemetry-collector-contrib/exporter/alibabacloudlogserviceexporter => ./exporter/alibabacloudlogserviceexporter

internal/scrapertest/Makefile

@@ -0,0 +1 @@
+include ../../Makefile.Common

internal/scrapertest/expected.go

@@ -0,0 +1,46 @@
+// 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 scrapertest
+
+import (
+	"encoding/json"
+	"io/ioutil"
+
+	"go.opentelemetry.io/collector/model/otlp"
+	"go.opentelemetry.io/collector/model/pdata"
+)
+
+func ReadExpected(filePath string) (pdata.Metrics, error) {
+	expectedFileBytes, err := ioutil.ReadFile(filePath)
+	if err != nil {
+		return pdata.Metrics{}, err
+	}
+	unmarshaller := otlp.NewJSONMetricsUnmarshaler()
+	return unmarshaller.UnmarshalMetrics(expectedFileBytes)
+}
+
+func WriteExpected(filePath string, metrics pdata.Metrics) error {
+	bytes, err := otlp.NewJSONMetricsMarshaler().MarshalMetrics(metrics)
+	if err != nil {
+		return err
+	}
+	var jsonVal map[string]interface{}
+	json.Unmarshal(bytes, &jsonVal)
+	b, err := json.MarshalIndent(jsonVal, "", "   ")
+	if err != nil {
+		return err
+	}
+	return ioutil.WriteFile(filePath, b, 0600)
+}

internal/scrapertest/expected_test.go

@@ -0,0 +1,67 @@
+// 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 scrapertest
+
+import (
+	"io/ioutil"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/model/pdata"
+)
+
+func TestWriteExpected(t *testing.T) {
+	metricslice := baseTestMetrics()
+	metrics := pdata.NewMetrics()
+	metricslice.CopyTo(metrics.ResourceMetrics().AppendEmpty().InstrumentationLibraryMetrics().AppendEmpty().Metrics())
+
+	tempDir := filepath.Join(t.TempDir(), "metrics.json")
+	WriteExpected(tempDir, metrics)
+
+	actualBytes, err := ioutil.ReadFile(tempDir)
+	require.NoError(t, err)
+
+	expectedFile := filepath.Join("testdata", "roundtrip", "expected.json")
+	expectedBytes, err := ioutil.ReadFile(expectedFile)
+	require.NoError(t, err)
+
+	require.Equal(t, expectedBytes, actualBytes)
+}
+
+func TestReadExpected(t *testing.T) {
+	metricslice := baseTestMetrics()
+	expectedMetrics := pdata.NewMetrics()
+	metricslice.CopyTo(expectedMetrics.ResourceMetrics().AppendEmpty().InstrumentationLibraryMetrics().AppendEmpty().Metrics())
+
+	expectedFile := filepath.Join("testdata", "roundtrip", "expected.json")
+	actualMetrics, err := ReadExpected(expectedFile)
+	require.NoError(t, err)
+	require.Equal(t, expectedMetrics, actualMetrics)
+}
+
+func TestRoundTrip(t *testing.T) {
+	metricslice := baseTestMetrics()
+	expectedMetrics := pdata.NewMetrics()
+	metricslice.CopyTo(expectedMetrics.ResourceMetrics().AppendEmpty().InstrumentationLibraryMetrics().AppendEmpty().Metrics())
+
+	tempDir := filepath.Join(t.TempDir(), "metrics.json")
+	err := WriteExpected(tempDir, expectedMetrics)
+	require.NoError(t, err)
+
+	actualMetrics, err := ReadExpected(tempDir)
+	require.NoError(t, err)
+	require.Equal(t, expectedMetrics, actualMetrics)
+}

internal/scrapertest/go.mod

@@ -0,0 +1,27 @@
+module github.com/open-telemetry/opentelemetry-collector-contrib/internal/scrapertest
+
+go 1.17
+
+require (
+	github.com/stretchr/testify v1.7.0
+	go.opentelemetry.io/collector/model v0.36.1-0.20211004155959-190f8fbb2b9a
+	go.uber.org/multierr v1.7.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/kr/pretty v0.3.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.uber.org/atomic v1.7.0 // indirect
+	golang.org/x/net v0.0.0-20210614182718-04defd469f4e // indirect
+	golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 // indirect
+	golang.org/x/text v0.3.6 // indirect
+	google.golang.org/genproto v0.0.0-20210604141403-392c879c8b08 // indirect
+	google.golang.org/grpc v1.41.0 // indirect
+	google.golang.org/protobuf v1.27.1 // indirect
+	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
+)
+
+replace github.com/open-telemetry/opentelemetry-collector-contrib/receiver/scraperhelper => ../../receiver/scraperhelper