[receiver/pulsar] do not expose method (open-telemetry#27029)

**Description:** 
Do not export functions `WithLogsUnmarshalers`,
`WithMetricsUnmarshalers`, `WithTracesUnmarshalers`, add tests for that
and pass checkapi

**Link to tracking Issue:**

open-telemetry#26304

**Testing:** 
go run cmd/checkapi/main.go .
make chlog-validate
go test for pulsarreceiver

**Documentation:**

.chloggen/pulsarreceiver-checkapi-26304.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: breaking
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: pulsarreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Do not export the functions `WithLogsUnmarshalers`, `WithMetricsUnmarshalers`, `WithTracesUnmarshalers`, add tests and pass checkapi.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [26304]
+
+# (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:
+
+# 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]

cmd/checkapi/allowlist.txt

@@ -8,5 +8,4 @@ receiver/dockerstatsreceiver
 receiver/journaldreceiver
 receiver/kafkareceiver
 receiver/podmanreceiver
-receiver/pulsarreceiver
 receiver/windowseventlogreceiver

receiver/pulsarreceiver/factory.go

@@ -26,26 +26,26 @@ const (
 // FactoryOption applies changes to PulsarExporterFactory.
 type FactoryOption func(factory *pulsarReceiverFactory)
 
-// WithTracesUnmarshalers adds Unmarshalers.
-func WithTracesUnmarshalers(tracesUnmarshalers ...TracesUnmarshaler) FactoryOption {
+// withTracesUnmarshalers adds Unmarshalers.
+func withTracesUnmarshalers(tracesUnmarshalers ...TracesUnmarshaler) FactoryOption {
 	return func(factory *pulsarReceiverFactory) {
 		for _, unmarshaler := range tracesUnmarshalers {
 			factory.tracesUnmarshalers[unmarshaler.Encoding()] = unmarshaler
 		}
 	}
 }
 
-// WithMetricsUnmarshalers adds MetricsUnmarshalers.
-func WithMetricsUnmarshalers(metricsUnmarshalers ...MetricsUnmarshaler) FactoryOption {
+// withMetricsUnmarshalers adds MetricsUnmarshalers.
+func withMetricsUnmarshalers(metricsUnmarshalers ...MetricsUnmarshaler) FactoryOption {
 	return func(factory *pulsarReceiverFactory) {
 		for _, unmarshaler := range metricsUnmarshalers {
 			factory.metricsUnmarshalers[unmarshaler.Encoding()] = unmarshaler
 		}
 	}
 }
 
-// WithLogsUnmarshalers adds LogsUnmarshalers.
-func WithLogsUnmarshalers(logsUnmarshalers ...LogsUnmarshaler) FactoryOption {
+// withLogsUnmarshalers adds LogsUnmarshalers.
+func withLogsUnmarshalers(logsUnmarshalers ...LogsUnmarshaler) FactoryOption {
 	return func(factory *pulsarReceiverFactory) {
 		for _, unmarshaler := range logsUnmarshalers {
 			factory.logsUnmarshalers[unmarshaler.Encoding()] = unmarshaler

receiver/pulsarreceiver/factory_test.go

@@ -9,6 +9,9 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/pdata/plog"
+	"go.opentelemetry.io/collector/pdata/pmetric"
+	"go.opentelemetry.io/collector/pdata/ptrace"
 	"go.opentelemetry.io/collector/receiver/receivertest"
 )
 
@@ -53,6 +56,25 @@ func Test_CreateTraceReceiver(t *testing.T) {
 	assert.NotNil(t, recv)
 }
 
+func TestWithTracesUnmarshalers(t *testing.T) {
+	unmarshaler := &customTracesUnmarshaler{}
+	f := NewFactory(withTracesUnmarshalers(unmarshaler))
+	cfg := createDefaultConfig().(*Config)
+
+	t.Run("custom_encoding", func(t *testing.T) {
+		cfg.Encoding = unmarshaler.Encoding()
+		receiver, err := f.CreateTracesReceiver(context.Background(), receivertest.NewNopCreateSettings(), cfg, nil)
+		require.NoError(t, err)
+		require.NotNil(t, receiver)
+	})
+	t.Run("default_encoding", func(t *testing.T) {
+		cfg.Encoding = defaultEncoding
+		receiver, err := f.CreateTracesReceiver(context.Background(), receivertest.NewNopCreateSettings(), cfg, nil)
+		require.NoError(t, err)
+		assert.NotNil(t, receiver)
+	})
+}
+
 // metrics
 func TestCreateMetricsReceiver_err_addr(t *testing.T) {
 	cfg := createDefaultConfig().(*Config)
@@ -83,6 +105,25 @@ func Test_CreateMetricsReceiver(t *testing.T) {
 	assert.NotNil(t, recv)
 }
 
+func TestWithMetricsUnmarshalers(t *testing.T) {
+	unmarshaler := &customMetricsUnmarshaler{}
+	f := NewFactory(withMetricsUnmarshalers(unmarshaler))
+	cfg := createDefaultConfig().(*Config)
+
+	t.Run("custom_encoding", func(t *testing.T) {
+		cfg.Encoding = unmarshaler.Encoding()
+		receiver, err := f.CreateMetricsReceiver(context.Background(), receivertest.NewNopCreateSettings(), cfg, nil)
+		require.NoError(t, err)
+		require.NotNil(t, receiver)
+	})
+	t.Run("default_encoding", func(t *testing.T) {
+		cfg.Encoding = defaultEncoding
+		receiver, err := f.CreateMetricsReceiver(context.Background(), receivertest.NewNopCreateSettings(), cfg, nil)
+		require.NoError(t, err)
+		assert.NotNil(t, receiver)
+	})
+}
+
 // logs
 func TestCreateLogsReceiver_err_addr(t *testing.T) {
 	cfg := createDefaultConfig().(*Config)
@@ -113,3 +154,55 @@ func Test_CreateLogsReceiver(t *testing.T) {
 	require.NoError(t, err)
 	assert.NotNil(t, recv)
 }
+
+func TestWithLogsUnmarshalers(t *testing.T) {
+	unmarshaler := &customLogsUnmarshaler{}
+	f := NewFactory(withLogsUnmarshalers(unmarshaler))
+	cfg := createDefaultConfig().(*Config)
+
+	t.Run("custom_encoding", func(t *testing.T) {
+		cfg.Encoding = unmarshaler.Encoding()
+		exporter, err := f.CreateLogsReceiver(context.Background(), receivertest.NewNopCreateSettings(), cfg, nil)
+		require.NoError(t, err)
+		require.NotNil(t, exporter)
+	})
+	t.Run("default_encoding", func(t *testing.T) {
+		cfg.Encoding = defaultEncoding
+		exporter, err := f.CreateLogsReceiver(context.Background(), receivertest.NewNopCreateSettings(), cfg, nil)
+		require.NoError(t, err)
+		assert.NotNil(t, exporter)
+	})
+}
+
+type customTracesUnmarshaler struct {
+}
+
+type customMetricsUnmarshaler struct {
+}
+
+type customLogsUnmarshaler struct {
+}
+
+func (c customTracesUnmarshaler) Unmarshal([]byte) (ptrace.Traces, error) {
+	panic("implement me")
+}
+
+func (c customTracesUnmarshaler) Encoding() string {
+	return "custom"
+}
+
+func (c customMetricsUnmarshaler) Unmarshal([]byte) (pmetric.Metrics, error) {
+	panic("implement me")
+}
+
+func (c customMetricsUnmarshaler) Encoding() string {
+	return "custom"
+}
+
+func (c customLogsUnmarshaler) Unmarshal([]byte) (plog.Logs, error) {
+	panic("implement me")
+}
+
+func (c customLogsUnmarshaler) Encoding() string {
+	return "custom"
+}