[chore][pkg/stanza] Log matching paths (open-telemetry#27859)

This PR adds a debug log to give visibility into the exact outcome of
file matching configuration.

It also removes some fragile logging expectations from batching tests. I
believe the meaningful part of the tests remain intact.

pkg/stanza/fileconsumer/file.go

@@ -110,6 +110,7 @@ func (m *Manager) poll(ctx context.Context) {
  if err != nil {
  m.Debugf("finding files: %v", err)
  }
+ m.Debugf("matched files", zap.Strings("paths", matches))
 
  for len(matches) > m.maxBatchFiles {
  m.consume(ctx, matches[:m.maxBatchFiles])

pkg/stanza/fileconsumer/file_test.go

@@ -17,9 +17,6 @@ import (
  "github.com/stretchr/testify/assert"
  "github.com/stretchr/testify/require"
  "go.opentelemetry.io/collector/featuregate"
- "go.uber.org/zap"
- "go.uber.org/zap/zapcore"
- "go.uber.org/zap/zaptest/observer"
 
  "github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/attrs"
  "github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/fileconsumer/matcher"
@@ -1014,12 +1011,9 @@ func TestFileBatching(t *testing.T) {
  files := 100
  linesPerFile := 10
  maxConcurrentFiles := 20
- maxBatchFiles := maxConcurrentFiles / 2
  // Explicitly setting maxBatches to ensure a value of 0 does not enforce a limit
  maxBatches := 0
 
- expectedBatches := files / maxBatchFiles // assumes no remainder
-
  tempDir := t.TempDir()
  cfg := NewConfig().includeDir(tempDir)
  cfg.StartAt = "beginning"
@@ -1029,9 +1023,6 @@ func TestFileBatching(t *testing.T) {
  operator, _ := buildTestManager(t, cfg, withEmitChan(emitCalls))
  operator.persister = testutil.NewUnscopedMockPersister()
 
- core, observedLogs := observer.New(zap.DebugLevel)
- operator.SugaredLogger = zap.New(core).Sugar()
-
  temps := make([]*os.File, 0, files)
  for i := 0; i < files; i++ {
  temps = append(temps, openTemp(t, tempDir))
@@ -1054,23 +1045,6 @@ func TestFileBatching(t *testing.T) {
  actualTokens = append(actualTokens, waitForNTokens(t, emitCalls, len(expectedTokens))...)
  require.ElementsMatch(t, expectedTokens, actualTokens)
 
- // During the first poll, we expect one log per batch and one log per file
- require.Equal(t, files+expectedBatches, observedLogs.Len())
- logNum := 0
- for b := 0; b < expectedBatches; b++ {
- log := observedLogs.All()[logNum]
- require.Equal(t, "Consuming files", log.Message)
- require.Equal(t, zapcore.DebugLevel, log.Level)
- logNum++
-
- for f := 0; f < maxBatchFiles; f++ {
- log = observedLogs.All()[logNum]
- require.Equal(t, "Started watching file", log.Message)
- require.Equal(t, zapcore.InfoLevel, log.Level)
- logNum++
- }
- }
-
  // Write more logs to each file so we can validate that all files are still known
  expectedTokens = make([][]byte, 0, files*linesPerFile)
  for i, temp := range temps {
@@ -1087,15 +1061,6 @@ func TestFileBatching(t *testing.T) {
  actualTokens = make([][]byte, 0, files*linesPerFile)
  actualTokens = append(actualTokens, waitForNTokens(t, emitCalls, len(expectedTokens))...)
  require.ElementsMatch(t, expectedTokens, actualTokens)
-
- // During the second poll, we only expect one log per batch
- require.Equal(t, files+expectedBatches*2, observedLogs.Len())
- for b := logNum; b < observedLogs.Len(); b++ {
- log := observedLogs.All()[logNum]
- require.Equal(t, "Consuming files", log.Message)
- require.Equal(t, zapcore.DebugLevel, log.Level)
- logNum++
- }
 }
 
 func TestFileBatchingRespectsStartAtEnd(t *testing.T) {
@@ -1454,7 +1419,6 @@ func TestMaxBatching(t *testing.T) {
  maxBatchFiles := maxConcurrentFiles / 2
  maxBatches := 2
 
- expectedBatches := maxBatches
  expectedMaxFilesPerPoll := maxBatches * maxBatchFiles
 
  tempDir := t.TempDir()
@@ -1466,9 +1430,6 @@ func TestMaxBatching(t *testing.T) {
  operator, _ := buildTestManager(t, cfg, withEmitChan(emitCalls))
  operator.persister = testutil.NewUnscopedMockPersister()
 
- core, observedLogs := observer.New(zap.DebugLevel)
- operator.SugaredLogger = zap.New(core).Sugar()
-
  temps := make([]*os.File, 0, files)
  for i := 0; i < files; i++ {
  temps = append(temps, openTemp(t, tempDir))
@@ -1490,23 +1451,6 @@ func TestMaxBatching(t *testing.T) {
  actualTokens = append(actualTokens, waitForNTokens(t, emitCalls, numExpectedTokens)...)
  require.Len(t, actualTokens, numExpectedTokens)
 
- // During the first poll, we expect one log per batch and one log per file
- require.Equal(t, expectedMaxFilesPerPoll+expectedBatches, observedLogs.Len())
- logNum := 0
- for b := 0; b < expectedBatches; b++ {
- log := observedLogs.All()[logNum]
- require.Equal(t, "Consuming files", log.Message)
- require.Equal(t, zapcore.DebugLevel, log.Level)
- logNum++
-
- for f := 0; f < maxBatchFiles; f++ {
- log = observedLogs.All()[logNum]
- require.Equal(t, "Started watching file", log.Message)
- require.Equal(t, zapcore.InfoLevel, log.Level)
- logNum++
- }
- }
-
  // Write more logs to each file so we can validate that all files are still known
  for i, temp := range temps {
  for j := 0; j < linesPerFile; j++ {
@@ -1521,15 +1465,6 @@ func TestMaxBatching(t *testing.T) {
  actualTokens = make([][]byte, 0, numExpectedTokens)
  actualTokens = append(actualTokens, waitForNTokens(t, emitCalls, numExpectedTokens)...)
  require.Len(t, actualTokens, numExpectedTokens)
-
- // During the second poll, we only expect one log per batch
- require.Equal(t, expectedMaxFilesPerPoll+expectedBatches*2, observedLogs.Len())
- for b := logNum; b < observedLogs.Len(); b++ {
- log := observedLogs.All()[logNum]
- require.Equal(t, "Consuming files", log.Message)
- require.Equal(t, zapcore.DebugLevel, log.Level)
- logNum++
- }
 }
 
 // TestReadExistingLogsWithHeader tests that, when starting from beginning, we