[pkg/golden] expose writing golden data to files outside of a test (#39673)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description
Expose methods to write data to file outside of the scope of a test

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: atoulme

.chloggen/golden_write.yaml

@@ -0,0 +1,31 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: pkg/golden
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Expose methods to write data to file outside of the scope of a test
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [39673]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: |
+  Expose WriteMetricsToFile to write pmetric data to a file outside of the scope of a test.
+  Expose WriteTracesToFile to write ptrace data to a file outside of the scope of a test
+  Expose WriteLogsToFile to write plog data to a file outside of the scope of a test
+  Expose WriteProfilesToFile to write pprofile data to a file outside of the scope of a test
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [api]

pkg/golden/golden.go

@@ -39,7 +39,7 @@ func ReadMetrics(filePath string) (pmetric.Metrics, error) {
 
 // WriteMetrics writes a pmetric.Metrics to the specified file in YAML format.
 func WriteMetrics(tb testing.TB, filePath string, metrics pmetric.Metrics, opts ...WriteMetricsOption) error {
-	if err := writeMetrics(filePath, metrics, opts...); err != nil {
+	if err := WriteMetricsToFile(filePath, metrics, opts...); err != nil {
 		return err
 	}
 	tb.Logf("Golden file successfully written to %s.", filePath)
@@ -68,8 +68,9 @@ func MarshalMetricsYAML(metrics pmetric.Metrics) ([]byte, error) {
 	return b.Bytes(), nil
 }
 
-// writeMetrics writes a pmetric.Metrics to the specified file in YAML format.
-func writeMetrics(filePath string, metrics pmetric.Metrics, opts ...WriteMetricsOption) error {
+// WriteMetricsToFile writes a pmetric.Metrics to the specified file in YAML format.
+// Prefer using WriteMetrics in tests.
+func WriteMetricsToFile(filePath string, metrics pmetric.Metrics, opts ...WriteMetricsOption) error {
 	optsStruct := writeMetricsOptions{
 		normalizeTimestamps: true,
 	}
@@ -112,7 +113,7 @@ func ReadLogs(filePath string) (plog.Logs, error) {
 
 // WriteLogs writes a plog.Logs to the specified file in YAML format.
 func WriteLogs(tb testing.TB, filePath string, logs plog.Logs) error {
-	if err := writeLogs(filePath, logs); err != nil {
+	if err := WriteLogsToFile(filePath, logs); err != nil {
 		return err
 	}
 	tb.Logf("Golden file successfully written to %s.", filePath)
@@ -121,8 +122,9 @@ func WriteLogs(tb testing.TB, filePath string, logs plog.Logs) error {
 	return nil
 }
 
-// writeLogs writes a plog.Logs to the specified file in YAML format.
-func writeLogs(filePath string, logs plog.Logs) error {
+// WriteLogsToFile writes a plog.Logs to the specified file in YAML format.
+// Prefer using WriteLogs in tests.
+func WriteLogsToFile(filePath string, logs plog.Logs) error {
 	unmarshaler := &plog.JSONMarshaler{}
 	fileBytes, err := unmarshaler.MarshalLogs(logs)
 	if err != nil {
@@ -163,7 +165,7 @@ func ReadTraces(filePath string) (ptrace.Traces, error) {
 
 // WriteTraces writes a ptrace.Traces to the specified file in YAML format.
 func WriteTraces(tb testing.TB, filePath string, traces ptrace.Traces) error {
-	if err := writeTraces(filePath, traces); err != nil {
+	if err := WriteTracesToFile(filePath, traces); err != nil {
 		return err
 	}
 	tb.Logf("Golden file successfully written to %s.", filePath)
@@ -172,8 +174,9 @@ func WriteTraces(tb testing.TB, filePath string, traces ptrace.Traces) error {
 	return nil
 }
 
-// writeTraces writes a ptrace.Traces to the specified file
-func writeTraces(filePath string, traces ptrace.Traces) error {
+// WriteTracesToFile writes a ptrace.Traces to the specified file
+// Prefer using WriteTraces in tests.
+func WriteTracesToFile(filePath string, traces ptrace.Traces) error {
 	unmarshaler := &ptrace.JSONMarshaler{}
 	fileBytes, err := unmarshaler.MarshalTraces(traces)
 	if err != nil {
@@ -214,7 +217,7 @@ func ReadProfiles(filePath string) (pprofile.Profiles, error) {
 
 // WriteProfiles writes a pprofile.Profiles to the specified file in YAML format.
 func WriteProfiles(tb testing.TB, filePath string, profiles pprofile.Profiles) error {
-	if err := writeProfiles(filePath, profiles); err != nil {
+	if err := WriteProfilesToFile(filePath, profiles); err != nil {
 		return err
 	}
 	tb.Logf("Golden file successfully written to %s.", filePath)
@@ -223,8 +226,9 @@ func WriteProfiles(tb testing.TB, filePath string, profiles pprofile.Profiles) e
 	return nil
 }
 
-// writeProfiles writes a pprofile.Profiles to the specified file in YAML format.
-func writeProfiles(filePath string, profiles pprofile.Profiles) error {
+// WriteProfilesToFile writes a pprofile.Profiles to the specified file in YAML format.
+// Prefer using WriteProfiles in tests.
+func WriteProfilesToFile(filePath string, profiles pprofile.Profiles) error {
 	unmarshaler := &pprofile.JSONMarshaler{}
 	fileBytes, err := unmarshaler.MarshalProfiles(profiles)
 	if err != nil {

pkg/golden/golden_test.go

@@ -26,7 +26,7 @@ func TestWriteMetrics(t *testing.T) {
 	metricslice.CopyTo(metrics.ResourceMetrics().AppendEmpty().ScopeMetrics().AppendEmpty().Metrics())
 
 	actualFile := filepath.Join(t.TempDir(), "metrics.yaml")
-	require.NoError(t, writeMetrics(actualFile, metrics))
+	require.NoError(t, WriteMetricsToFile(actualFile, metrics))
 
 	actualBytes, err := os.ReadFile(actualFile)
 	require.NoError(t, err)
@@ -49,7 +49,7 @@ func TestWriteMetrics_SkipTimestampNormalization(t *testing.T) {
 	metricslice.CopyTo(metrics.ResourceMetrics().AppendEmpty().ScopeMetrics().AppendEmpty().Metrics())
 
 	actualFile := filepath.Join(t.TempDir(), "metrics.yaml")
-	require.NoError(t, writeMetrics(actualFile, metrics, SkipMetricTimestampNormalization()))
+	require.NoError(t, WriteMetricsToFile(actualFile, metrics, SkipMetricTimestampNormalization()))
 
 	actualBytes, err := os.ReadFile(actualFile)
 	require.NoError(t, err)
@@ -83,7 +83,7 @@ func TestRoundTrip(t *testing.T) {
 	metricslice.CopyTo(expectedMetrics.ResourceMetrics().AppendEmpty().ScopeMetrics().AppendEmpty().Metrics())
 
 	tempDir := filepath.Join(t.TempDir(), "metrics.yaml")
-	require.NoError(t, writeMetrics(tempDir, expectedMetrics))
+	require.NoError(t, WriteMetricsToFile(tempDir, expectedMetrics))
 
 	actualMetrics, err := ReadMetrics(tempDir)
 	require.NoError(t, err)
@@ -186,7 +186,7 @@ func TestWriteLogs(t *testing.T) {
 	logs := CreateTestLogs()
 
 	actualFile := filepath.Join(t.TempDir(), "logs.yaml")
-	require.NoError(t, writeLogs(actualFile, logs))
+	require.NoError(t, WriteLogsToFile(actualFile, logs))
 
 	actualBytes, err := os.ReadFile(actualFile)
 	require.NoError(t, err)
@@ -207,7 +207,7 @@ func TestLogsRoundTrip(t *testing.T) {
 	expectedLogs := CreateTestLogs()
 
 	tempDir := filepath.Join(t.TempDir(), "logs.yaml")
-	require.NoError(t, writeLogs(tempDir, expectedLogs))
+	require.NoError(t, WriteLogsToFile(tempDir, expectedLogs))
 
 	actualLogs, err := ReadLogs(tempDir)
 	require.NoError(t, err)
@@ -251,7 +251,7 @@ func TestWriteTraces(t *testing.T) {
 	traces := CreateTestTraces()
 
 	actualFile := filepath.Join("./testdata/traces-roundtrip", "traces.yaml")
-	require.NoError(t, writeTraces(actualFile, traces))
+	require.NoError(t, WriteTracesToFile(actualFile, traces))
 
 	actualBytes, err := os.ReadFile(actualFile)
 	require.NoError(t, err)
@@ -338,7 +338,7 @@ func TestWriteProfiles(t *testing.T) {
 	profiles := CreateTestProfiles()
 
 	actualFile := filepath.Join(t.TempDir(), "profiles.yaml")
-	require.NoError(t, writeProfiles(actualFile, profiles))
+	require.NoError(t, WriteProfilesToFile(actualFile, profiles))
 
 	actualBytes, err := os.ReadFile(actualFile)
 	require.NoError(t, err)
@@ -359,7 +359,7 @@ func TestProfilesRoundTrip(t *testing.T) {
 	expectedProfiles := CreateTestProfiles()
 
 	tempDir := filepath.Join(t.TempDir(), "profiles.yaml")
-	require.NoError(t, writeProfiles(tempDir, expectedProfiles))
+	require.NoError(t, WriteProfilesToFile(tempDir, expectedProfiles))
 
 	actualProfiles, err := ReadProfiles(tempDir)
 	require.NoError(t, err)