improve test coverage

exporter/prometheusremotewriteexporter/exporter.go

@@ -50,7 +50,7 @@ type prwExporter struct {
 
 // newPrwExporter initializes a new prwExporter instance and sets fields accordingly.
 // client parameter cannot be nil.
-func newPrwExporter(namespace string, endpoint string, client *http.Client) (*prwExporter, error) {
+func newPrwExporter(namespace string, endpoint string, client *http.Client, headers map[string]string) (*prwExporter, error) {
 
 	if client == nil {
 		return nil, errors.Errorf("http client cannot be nil")
@@ -65,6 +65,7 @@ func newPrwExporter(namespace string, endpoint string, client *http.Client) (*pr
 		namespace:   namespace,
 		endpointURL: endpointURL,
 		client:      client,
+		headers:     headers,
 		wg:          new(sync.WaitGroup),
 		closeChan:   make(chan struct{}),
 	}, nil

exporter/prometheusremotewriteexporter/exporter_test.go

@@ -356,7 +356,7 @@ func Test_newPrwExporter(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			prwe, err := newPrwExporter(tt.namespace, tt.endpoint, tt.client)
+			prwe, err := newPrwExporter(tt.namespace, tt.endpoint, tt.client, testHeaders)
 			if tt.returnError {
 				assert.Error(t, err)
 				return
@@ -493,7 +493,7 @@ func runExportPipeline(t *testing.T, ts *prompb.TimeSeries, endpoint *url.URL) e
 
 	HTTPClient := http.DefaultClient
 	//after this, instantiate a CortexExporter with the current HTTP client and endpoint set to passed in endpoint
-	prwe, err := newPrwExporter("test", endpoint.String(), HTTPClient)
+	prwe, err := newPrwExporter("test", endpoint.String(), HTTPClient, testHeaders)
 	if err != nil {
 		return err
 	}
@@ -722,7 +722,7 @@ func Test_pushMetrics(t *testing.T) {
 			// c, err := config.HTTPClientSettings.ToClient()
 			// assert.Nil(t, err)
 			c := http.DefaultClient
-			prwe, nErr := newPrwExporter(config.Namespace, serverURL.String(), c)
+			prwe, nErr := newPrwExporter(config.Namespace, serverURL.String(), c, testHeaders)
 			require.NoError(t, nErr)
 			numDroppedTimeSeries, err := prwe.pushMetrics(context.Background(), *tt.md)
 			assert.Equal(t, tt.numDroppedTimeSeries, numDroppedTimeSeries)

exporter/prometheusremotewriteexporter/factory.go

@@ -17,6 +17,8 @@ package prometheusremotewriteexporter
 import (
 	"context"
 
+	"github.com/pkg/errors"
+
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/config/confighttp"
 	"go.opentelemetry.io/collector/config/configmodels"
@@ -39,15 +41,18 @@ func NewFactory() component.ExporterFactory {
 func createMetricsExporter(_ context.Context, _ component.ExporterCreateParams,
 	cfg configmodels.Exporter) (component.MetricsExporter, error) {
 
-	cCfg := cfg.(*Config)
+	cCfg, ok := cfg.(*Config)
+	if !ok {
+		return nil, errors.Errorf("invalid configuration")
+	}
 
 	client, err := cCfg.HTTPClientSettings.ToClient()
 
 	if err != nil {
 		return nil, err
 	}
 
-	prwe, err := newPrwExporter(cCfg.Namespace, cCfg.HTTPClientSettings.Endpoint, client)
+	prwe, err := newPrwExporter(cCfg.Namespace, cCfg.HTTPClientSettings.Endpoint, client, cCfg.Headers)
 
 	if err != nil {
 		return nil, err

exporter/prometheusremotewriteexporter/factory_test.go

@@ -16,6 +16,7 @@ package prometheusremotewriteexporter
 
 import (
 	"context"
+	"go.opentelemetry.io/collector/config/confighttp"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -27,31 +28,43 @@ import (
 
 //Tests whether or not the default Exporter factory can instantiate a properly interfaced Exporter with default conditions
 func TestCreateDefaultConfig(t *testing.T) {
-	factory := NewFactory()
-	cfg := factory.CreateDefaultConfig()
+	cfg := createDefaultConfig()
 	assert.NotNil(t, cfg, "failed to create default config")
 	assert.NoError(t, configcheck.ValidateConfig(cfg))
 }
 
 //Tests whether or not a correct Metrics Exporter from the default Config parameters
 func TestCreateMetricsExporter(t *testing.T) {
-	factory := NewFactory()
+
+	invalidConfig := createDefaultConfig().(*Config)
+	invalidConfig.HTTPClientSettings = confighttp.HTTPClientSettings{}
+
 	tests := []struct {
 		name        string
 		cfg         configmodels.Exporter
 		params      component.ExporterCreateParams
 		returnError bool
 	}{
 		{"success_case",
-			factory.CreateDefaultConfig(),
+			createDefaultConfig(),
 			component.ExporterCreateParams{},
 			false,
 		},
+		{"fail_case",
+			nil,
+			component.ExporterCreateParams{},
+			true,
+		},
+		{"invalid_config_case",
+			invalidConfig,
+			component.ExporterCreateParams{},
+			true,
+		},
 	}
 	// run tests
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			_, err := factory.CreateMetricsExporter(context.Background(), tt.params, tt.cfg)
+			_, err := createMetricsExporter(context.Background(), tt.params, tt.cfg)
 			if tt.returnError {
 				assert.Error(t, err)
 				return

exporter/prometheusremotewriteexporter/helper_test.go

@@ -205,11 +205,17 @@ func Test_createLabelSet(t *testing.T) {
 			getPromLabels(label11+"_", value11, "key_"+label12, value12, label31+"_", value31, label32, value32),
 		},
 		{
-			"no_extras_case",
+			"no_original_case",
 			nil,
 			[]string{label31, value31, label32, value32},
 			getPromLabels(label31, value31, label32, value32),
 		},
+		{
+			"empty_extra_case",
+			lbs1,
+			[]string{"", ""},
+			getPromLabels(label11, value11, label12, value12, "", ""),
+		},
 		{
 			"single_left_over_case",
 			lbs1,

exporter/prometheusremotewriteexporter/testutil_test.go

@@ -33,6 +33,8 @@ var (
 	time1 = uint64(time.Now().UnixNano())
 	time2 = uint64(time.Date(1970, 1, 0, 0, 0, 0, 0, time.UTC).UnixNano())
 
+	testHeaders = map[string]string{"headerOne": "value1"}
+
 	typeInt64           = "INT64"
 	typeMonotonicInt64  = "MONOTONIC_INT64"
 	typeMonotonicDouble = "MONOTONIC_DOUBLE"