[chore][pkg/stanza] Localize one-off test utility code (open-telemetr…

…y#29644)

This PR moves localizes some test utility code. These functions are
either used only once, or only in one test file.

This is a step towards open-telemetry#29643, and ultimately towards sharing test
utilities across multiple packages.

pkg/stanza/fileconsumer/benchmark_test.go

@@ -4,6 +4,7 @@
 package fileconsumer
 
 import (
+	"context"
 	"os"
 	"path/filepath"
 	"testing"
@@ -161,7 +162,11 @@ func BenchmarkFileInput(b *testing.B) {
 
 			received := make(chan []byte)
 
-			op, err := cfg.Build(testutil.Logger(b), emitOnChan(received))
+			callback := func(_ context.Context, token []byte, _ map[string]any) error {
+				received <- token
+				return nil
+			}
+			op, err := cfg.Build(testutil.Logger(b), callback)
 			require.NoError(b, err)
 
 			// write half the lines before starting

pkg/stanza/fileconsumer/config_test.go

@@ -4,13 +4,15 @@
 package fileconsumer
 
 import (
+	"fmt"
 	"path/filepath"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"go.opentelemetry.io/collector/featuregate"
+	"go.uber.org/zap"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/fileconsumer/internal/fingerprint"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/fileconsumer/matcher"
@@ -798,3 +800,50 @@ func TestBuildWithHeader(t *testing.T) {
 		})
 	}
 }
+
+// includeDir is a builder-like helper for quickly setting up a test config
+func (c *Config) includeDir(dir string) *Config {
+	c.Include = append(c.Include, fmt.Sprintf("%s/*", dir))
+	return c
+}
+
+// withHeader is a builder-like helper for quickly setting up a test config header
+func (c *Config) withHeader(headerMatchPattern, extractRegex string) *Config {
+	regexOpConfig := regex.NewConfig()
+	regexOpConfig.Regex = extractRegex
+
+	c.Header = &HeaderConfig{
+		Pattern: headerMatchPattern,
+		MetadataOperators: []operator.Config{
+			{
+				Builder: regexOpConfig,
+			},
+		},
+	}
+
+	return c
+}
+
+const mockOperatorType = "mock"
+
+func init() {
+	operator.Register(mockOperatorType, func() operator.Builder { return newMockOperatorConfig(NewConfig()) })
+}
+
+type mockOperatorConfig struct {
+	helper.BasicConfig `mapstructure:",squash"`
+	*Config            `mapstructure:",squash"`
+}
+
+func newMockOperatorConfig(cfg *Config) *mockOperatorConfig {
+	return &mockOperatorConfig{
+		BasicConfig: helper.NewBasicConfig(mockOperatorType, mockOperatorType),
+		Config:      cfg,
+	}
+}
+
+// This function is impelmented for compatibility with operatortest
+// but is not meant to be used directly
+func (h *mockOperatorConfig) Build(*zap.SugaredLogger) (operator.Operator, error) {
+	panic("not impelemented")
+}

pkg/stanza/fileconsumer/rotation_test.go

@@ -7,13 +7,15 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"log"
 	"os"
 	"path/filepath"
 	"runtime"
 	"sync"
 	"testing"
 	"time"
 
+	"github.com/observiq/nanojack"
 	"github.com/stretchr/testify/require"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/testutil"
@@ -255,7 +257,20 @@ func (rt rotationTest) run(tc rotationTest, copyTruncate, sequential bool) func(
 		emitCalls := make(chan *emitParams, tc.totalLines)
 		operator, _ := buildTestManager(t, cfg, withEmitChan(emitCalls))
 
-		logger := getRotatingLogger(t, tempDir, tc.maxLinesPerFile, tc.maxBackupFiles, copyTruncate, sequential)
+		file, err := os.CreateTemp(tempDir, "")
+		require.NoError(t, err)
+		require.NoError(t, file.Close()) // will be managed by rotator
+
+		rotator := nanojack.Logger{
+			Filename:     file.Name(),
+			MaxLines:     tc.maxLinesPerFile,
+			MaxBackups:   tc.maxBackupFiles,
+			CopyTruncate: copyTruncate,
+			Sequential:   sequential,
+		}
+		t.Cleanup(func() { _ = rotator.Close() })
+
+		logger := log.New(&rotator, "", 0)
 
 		expected := make([][]byte, 0, tc.totalLines)
 		baseStr := string(tokenWithLength(46)) // + ' 123'

pkg/stanza/fileconsumer/util_test.go

@@ -6,21 +6,15 @@ package fileconsumer
 import (
 	"context"
 	"fmt"
-	"log"
 	"math/rand"
 	"os"
 	"path/filepath"
 	"testing"
 	"time"
 
-	"github.com/observiq/nanojack"
 	"github.com/stretchr/testify/require"
-	"go.uber.org/zap"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/fileconsumer/emit"
-	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/operator"
-	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/operator/helper"
-	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/operator/parser/regex"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/testutil"
 )
 
@@ -37,36 +31,6 @@ func testEmitFunc(emitChan chan *emitParams) emit.Callback {
 	}
 }
 
-// includeDir is a builder-like helper for quickly setting up a test config
-func (c *Config) includeDir(dir string) *Config {
-	c.Include = append(c.Include, fmt.Sprintf("%s/*", dir))
-	return c
-}
-
-// withHeader is a builder-like helper for quickly setting up a test config header
-func (c *Config) withHeader(headerMatchPattern, extractRegex string) *Config {
-	regexOpConfig := regex.NewConfig()
-	regexOpConfig.Regex = extractRegex
-
-	c.Header = &HeaderConfig{
-		Pattern: headerMatchPattern,
-		MetadataOperators: []operator.Config{
-			{
-				Builder: regexOpConfig,
-			},
-		},
-	}
-
-	return c
-}
-
-func emitOnChan(received chan []byte) emit.Callback {
-	return func(_ context.Context, token []byte, _ map[string]any) error {
-		received <- token
-		return nil
-	}
-}
-
 type emitParams struct {
 	attrs map[string]any
 	token []byte
@@ -117,24 +81,6 @@ func openTempWithPattern(t testing.TB, tempDir, pattern string) *os.File {
 	return file
 }
 
-func getRotatingLogger(t testing.TB, tempDir string, maxLines, maxBackups int, copyTruncate, sequential bool) *log.Logger {
-	file, err := os.CreateTemp(tempDir, "")
-	require.NoError(t, err)
-	require.NoError(t, file.Close()) // will be managed by rotator
-
-	rotator := nanojack.Logger{
-		Filename:     file.Name(),
-		MaxLines:     maxLines,
-		MaxBackups:   maxBackups,
-		CopyTruncate: copyTruncate,
-		Sequential:   sequential,
-	}
-
-	t.Cleanup(func() { _ = rotator.Close() })
-
-	return log.New(&rotator, "", 0)
-}
-
 func writeString(t testing.TB, file *os.File, s string) {
 	_, err := file.WriteString(s)
 	require.NoError(t, err)
@@ -218,27 +164,3 @@ func expectNoTokensUntil(t *testing.T, c chan *emitParams, d time.Duration) {
 	case <-time.After(d):
 	}
 }
-
-const mockOperatorType = "mock"
-
-func init() {
-	operator.Register(mockOperatorType, func() operator.Builder { return newMockOperatorConfig(NewConfig()) })
-}
-
-type mockOperatorConfig struct {
-	helper.BasicConfig `mapstructure:",squash"`
-	*Config            `mapstructure:",squash"`
-}
-
-func newMockOperatorConfig(cfg *Config) *mockOperatorConfig {
-	return &mockOperatorConfig{
-		BasicConfig: helper.NewBasicConfig(mockOperatorType, mockOperatorType),
-		Config:      cfg,
-	}
-}
-
-// This function is impelmented for compatibility with operatortest
-// but is not meant to be used directly
-func (h *mockOperatorConfig) Build(*zap.SugaredLogger) (operator.Operator, error) {
-	panic("not impelemented")
-}