Add tests

exporters/autoexport/exporter_test.go

@@ -16,6 +16,7 @@ package autoexport
 
 import (
 	"context"
+	"reflect"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -26,7 +27,7 @@ import (
 
 func TestOTLPExporterReturnedWhenNoEnvOrFallbackExporterConfigured(t *testing.T) {
 	exporter, err := NewSpanExporter(context.Background())
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.NotNil(t, exporter)
 	assert.IsType(t, &otlptrace.Exporter{}, exporter)
 }
@@ -37,7 +38,7 @@ func TestFallbackExporterReturnedWhenNoEnvExporterConfigured(t *testing.T) {
 		context.Background(),
 		WithFallbackSpanExporter(testExporter),
 	)
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, testExporter, exporter)
 }
 
@@ -49,8 +50,59 @@ func TestEnvExporterIsPreferredOverFallbackExporter(t *testing.T) {
 		context.Background(),
 		WithFallbackSpanExporter(testExporter),
 	)
-	assert.Nil(t, err)
-	assert.IsType(t, &otlptrace.Exporter{}, exporter)
+	assert.NoError(t, err)
+	assertOTLPHTTPExporter(t, exporter)
+}
+
+func TestEnvExporterOTLPOverHTTP(t *testing.T) {
+	t.Setenv("OTEL_TRACES_EXPORTER", "otlp")
+	t.Setenv("OTEL_EXPORTER_OTLP_PROTOCOL", "http/protobuf")
+
+	exporter, err := NewSpanExporter(context.Background())
+	assert.NoError(t, err)
+	assertOTLPHTTPExporter(t, exporter)
+}
+
+func TestEnvExporterOTLPOverGRPC(t *testing.T) {
+	t.Setenv("OTEL_TRACES_EXPORTER", "otlp")
+	t.Setenv("OTEL_EXPORTER_OTLP_PROTOCOL", "grpc")
+
+	exporter, err := NewSpanExporter(context.Background())
+	assert.NoError(t, err)
+	assertOTLPGRPCExporter(t, exporter)
+}
+
+func TestEnvExporterOTLPInvalidProtocol(t *testing.T) {
+	t.Setenv("OTEL_TRACES_EXPORTER", "otlp")
+	t.Setenv("OTEL_EXPORTER_OTLP_PROTOCOL", "invalid")
+
+	exporter, err := NewSpanExporter(context.Background())
+	assert.Error(t, err)
+	assert.Nil(t, exporter)
+}
+
+func assertOTLPHTTPExporter(t *testing.T, got trace.SpanExporter) {
+	t.Helper()
+
+	if !assert.IsType(t, &otlptrace.Exporter{}, got) {
+		return
+	}
+
+	// Implementation detail hack. This may break when bumping OTLP exporter modules as it uses unexported API.
+	clientType := reflect.Indirect(reflect.ValueOf(got)).FieldByName("client").Elem().Type().String()
+	assert.Equal(t, "*otlptracehttp.client", clientType)
+}
+
+func assertOTLPGRPCExporter(t *testing.T, got trace.SpanExporter) {
+	t.Helper()
+
+	if !assert.IsType(t, &otlptrace.Exporter{}, got) {
+		return
+	}
+
+	// Implementation detail hack. This may break when bumping OTLP exporter modules as it uses unexported API.
+	clientType := reflect.Indirect(reflect.ValueOf(got)).FieldByName("client").Elem().Type().String()
+	assert.Equal(t, "*otlptracegrpc.client", clientType)
 }
 
 type testExporter struct{}

exporters/autoexport/registry_test.go

@@ -75,7 +75,7 @@ func TestRegistryIsConcurrentSafe(t *testing.T) {
 		defer wg.Done()
 		assert.NotPanics(t, func() {
 			exp, err := r.load(context.Background(), exporterName)
-			assert.Nil(t, err, "missing exporter in registry")
+			assert.NoError(t, err, "missing exporter in registry")
 			assert.IsType(t, &stdouttrace.Exporter{}, exp)
 		})
 	}()
@@ -86,12 +86,13 @@ func TestRegistryIsConcurrentSafe(t *testing.T) {
 func TestSubsequentCallsToGetExporterReturnsNewInstances(t *testing.T) {
 	const exporterType = "otlp"
 	exp1, err := spanExporter(context.Background(), exporterType)
-	assert.Nil(t, err)
-	assert.IsType(t, &otlptrace.Exporter{}, exp1)
+	assert.NoError(t, err)
+	assertOTLPHTTPExporter(t, exp1)
 
 	exp2, err := spanExporter(context.Background(), exporterType)
-	assert.Nil(t, err)
-	assert.IsType(t, &otlptrace.Exporter{}, exp2)
+	assert.NoError(t, err)
+	assertOTLPHTTPExporter(t, exp2)
+
 	assert.NotSame(t, exp1, exp2)
 }