Fix small nits in pdata tests, add missing compatibility tests (#4931)

Signed-off-by: Bogdan Drutu <bogdandrutu@gmail.com>

model/pdata/logs_test.go

@@ -17,34 +17,37 @@ package pdata
 import (
 	"testing"
 
+	gogoproto "github.com/gogo/protobuf/proto"
 	"github.com/stretchr/testify/assert"
+	goproto "google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/types/known/emptypb"
 
 	"go.opentelemetry.io/collector/model/internal"
 	otlplogs "go.opentelemetry.io/collector/model/internal/data/protogen/logs/v1"
 )
 
 func TestLogRecordCount(t *testing.T) {
-	md := NewLogs()
-	assert.EqualValues(t, 0, md.LogRecordCount())
+	logs := NewLogs()
+	assert.EqualValues(t, 0, logs.LogRecordCount())
 
-	rl := md.ResourceLogs().AppendEmpty()
-	assert.EqualValues(t, 0, md.LogRecordCount())
+	rl := logs.ResourceLogs().AppendEmpty()
+	assert.EqualValues(t, 0, logs.LogRecordCount())
 
 	ill := rl.InstrumentationLibraryLogs().AppendEmpty()
-	assert.EqualValues(t, 0, md.LogRecordCount())
+	assert.EqualValues(t, 0, logs.LogRecordCount())
 
 	ill.LogRecords().AppendEmpty()
-	assert.EqualValues(t, 1, md.LogRecordCount())
+	assert.EqualValues(t, 1, logs.LogRecordCount())
 
-	rms := md.ResourceLogs()
+	rms := logs.ResourceLogs()
 	rms.EnsureCapacity(3)
 	rms.AppendEmpty().InstrumentationLibraryLogs().AppendEmpty()
 	illl := rms.AppendEmpty().InstrumentationLibraryLogs().AppendEmpty().LogRecords()
 	for i := 0; i < 5; i++ {
 		illl.AppendEmpty()
 	}
 	// 5 + 1 (from rms.At(0) initialized first)
-	assert.EqualValues(t, 6, md.LogRecordCount())
+	assert.EqualValues(t, 6, logs.LogRecordCount())
 }
 
 func TestLogRecordCountWithEmpty(t *testing.T) {
@@ -74,9 +77,42 @@ func TestLogRecordCountWithEmpty(t *testing.T) {
 
 func TestToFromLogProto(t *testing.T) {
 	wrapper := internal.LogsFromOtlp(&otlplogs.LogsData{})
-	ld := LogsFromInternalRep(wrapper)
-	assert.EqualValues(t, NewLogs(), ld)
-	assert.EqualValues(t, &otlplogs.LogsData{}, ld.orig)
+	logs := LogsFromInternalRep(wrapper)
+	assert.EqualValues(t, NewLogs(), logs)
+	assert.EqualValues(t, &otlplogs.LogsData{}, logs.orig)
+}
+
+func TestResourceLogsWireCompatibility(t *testing.T) {
+	// This test verifies that OTLP ProtoBufs generated using goproto lib in
+	// opentelemetry-proto repository OTLP ProtoBufs generated using gogoproto lib in
+	// this repository are wire compatible.
+
+	// Generate ResourceLogs as pdata struct.
+	logs := generateTestResourceLogs()
+
+	// Marshal its underlying ProtoBuf to wire.
+	wire1, err := gogoproto.Marshal(logs.orig)
+	assert.NoError(t, err)
+	assert.NotNil(t, wire1)
+
+	// Unmarshal from the wire to OTLP Protobuf in goproto's representation.
+	var goprotoMessage emptypb.Empty
+	err = goproto.Unmarshal(wire1, &goprotoMessage)
+	assert.NoError(t, err)
+
+	// Marshal to the wire again.
+	wire2, err := goproto.Marshal(&goprotoMessage)
+	assert.NoError(t, err)
+	assert.NotNil(t, wire2)
+
+	// Unmarshal from the wire into gogoproto's representation.
+	var gogoprotoRS2 otlplogs.ResourceLogs
+	err = gogoproto.Unmarshal(wire2, &gogoprotoRS2)
+	assert.NoError(t, err)
+
+	// Now compare that the original and final ProtoBuf messages are the same.
+	// This proves that goproto and gogoproto marshaling/unmarshaling are wire compatible.
+	assert.EqualValues(t, logs.orig, &gogoprotoRS2)
 }
 
 func TestLogsClone(t *testing.T) {

model/pdata/metrics_test.go

@@ -56,10 +56,10 @@ func TestResourceMetricsWireCompatibility(t *testing.T) {
 	// this repository are wire compatible.
 
 	// Generate ResourceMetrics as pdata struct.
-	pdataRM := generateTestResourceMetrics()
+	metrics := generateTestResourceMetrics()
 
 	// Marshal its underlying ProtoBuf to wire.
-	wire1, err := gogoproto.Marshal(pdataRM.orig)
+	wire1, err := gogoproto.Marshal(metrics.orig)
 	assert.NoError(t, err)
 	assert.NotNil(t, wire1)
 
@@ -80,7 +80,7 @@ func TestResourceMetricsWireCompatibility(t *testing.T) {
 
 	// Now compare that the original and final ProtoBuf messages are the same.
 	// This proves that goproto and gogoproto marshaling/unmarshaling are wire compatible.
-	assert.True(t, assert.EqualValues(t, pdataRM.orig, &gogoprotoRM))
+	assert.True(t, assert.EqualValues(t, metrics.orig, &gogoprotoRM))
 }
 
 func TestMetricCount(t *testing.T) {

model/pdata/traces_test.go

@@ -27,27 +27,27 @@ import (
 )
 
 func TestSpanCount(t *testing.T) {
-	md := NewTraces()
-	assert.EqualValues(t, 0, md.SpanCount())
+	traces := NewTraces()
+	assert.EqualValues(t, 0, traces.SpanCount())
 
-	rs := md.ResourceSpans().AppendEmpty()
-	assert.EqualValues(t, 0, md.SpanCount())
+	rs := traces.ResourceSpans().AppendEmpty()
+	assert.EqualValues(t, 0, traces.SpanCount())
 
 	ils := rs.InstrumentationLibrarySpans().AppendEmpty()
-	assert.EqualValues(t, 0, md.SpanCount())
+	assert.EqualValues(t, 0, traces.SpanCount())
 
 	ils.Spans().AppendEmpty()
-	assert.EqualValues(t, 1, md.SpanCount())
+	assert.EqualValues(t, 1, traces.SpanCount())
 
-	rms := md.ResourceSpans()
+	rms := traces.ResourceSpans()
 	rms.EnsureCapacity(3)
 	rms.AppendEmpty().InstrumentationLibrarySpans().AppendEmpty()
 	ilss := rms.AppendEmpty().InstrumentationLibrarySpans().AppendEmpty().Spans()
 	for i := 0; i < 5; i++ {
 		ilss.AppendEmpty()
 	}
 	// 5 + 1 (from rms.At(0) initialized first)
-	assert.EqualValues(t, 6, md.SpanCount())
+	assert.EqualValues(t, 6, traces.SpanCount())
 }
 
 func TestSpanCountWithEmpty(t *testing.T) {
@@ -76,9 +76,9 @@ func TestSpanCountWithEmpty(t *testing.T) {
 
 func TestToFromOtlp(t *testing.T) {
 	otlp := &otlptrace.TracesData{}
-	td := TracesFromInternalRep(internal.TracesFromOtlp(otlp))
-	assert.EqualValues(t, NewTraces(), td)
-	assert.EqualValues(t, otlp, internal.TracesToOtlp(td.InternalRep()))
+	traces := TracesFromInternalRep(internal.TracesFromOtlp(otlp))
+	assert.EqualValues(t, NewTraces(), traces)
+	assert.EqualValues(t, otlp, internal.TracesToOtlp(traces.InternalRep()))
 	// More tests in ./tracedata/traces_test.go. Cannot have them here because of
 	// circular dependency.
 }
@@ -89,10 +89,10 @@ func TestResourceSpansWireCompatibility(t *testing.T) {
 	// this repository are wire compatible.
 
 	// Generate ResourceSpans as pdata struct.
-	pdataRS := generateTestResourceSpans()
+	traces := generateTestResourceSpans()
 
 	// Marshal its underlying ProtoBuf to wire.
-	wire1, err := gogoproto.Marshal(pdataRS.orig)
+	wire1, err := gogoproto.Marshal(traces.orig)
 	assert.NoError(t, err)
 	assert.NotNil(t, wire1)
 
@@ -113,7 +113,7 @@ func TestResourceSpansWireCompatibility(t *testing.T) {
 
 	// Now compare that the original and final ProtoBuf messages are the same.
 	// This proves that goproto and gogoproto marshaling/unmarshaling are wire compatible.
-	assert.EqualValues(t, pdataRS.orig, &gogoprotoRS2)
+	assert.EqualValues(t, traces.orig, &gogoprotoRS2)
 }
 
 func TestTracesClone(t *testing.T) {