Add backup_writer_failure_HABITAT test and golden patch

backup_writer_failure_HABITAT_golden.go

@@ -0,0 +1,51 @@
+// backup_writer_failure_HABITAT_golden.go
+package badger
+
+import (
+	"bytes"
+	"errors"
+	"testing"
+)
+
+// failingWriter is a writer that always returns an error.
+type failingWriter struct{}
+
+func (f *failingWriter) Write(p []byte) (int, error) {
+	return 0, errors.New("writer failure")
+}
+
+func TestBackupWriterFailure_HABITAT(t *testing.T) {
+	// Use a temporary in-memory Badger DB for testing
+	opts := DefaultOptions("").WithInMemory(true)
+	db, err := Open(opts)
+	if err != nil {
+		t.Fatalf("Failed to open Badger DB: %v", err)
+	}
+	defer db.Close()
+
+	// Put a sample key-value pair
+	if err := db.Update(func(txn *Txn) error {
+		return txn.Set([]byte("key"), []byte("value"))
+	}); err != nil {
+		t.Fatalf("Failed to set key: %v", err)
+	}
+
+	// Use failingWriter to simulate backup writer failure
+	fw := &failingWriter{}
+
+	// db.Backup returns two values: ts and err
+	_, err = db.Backup(fw, 0)
+	if err == nil {
+		t.Fatalf("Expected Backup to fail due to writer error, but got nil")
+	}
+
+	// Also test a successful backup to ensure DB.Backup works
+	var buf bytes.Buffer
+	_, err = db.Backup(&buf, 0)
+	if err != nil {
+		t.Fatalf("Backup failed unexpectedly: %v", err)
+	}
+	if buf.Len() == 0 {
+		t.Fatalf("Expected backup data, got empty buffer")
+	}
+}

backup_writer_failure_HABITAT_test.go

@@ -0,0 +1,50 @@
+package badger_test
+
+import (
+	"bytes"
+	"fmt"
+	"testing"
+
+	"github.com/dgraph-io/badger/v4"
+)
+
+// failWriter simulates a writer that always fails
+type failWriter struct{}
+
+func (f *failWriter) Write(p []byte) (int, error) {
+	return 0, fmt.Errorf("writer failure")
+}
+
+func TestBackupWriterFailure_HABITAT(t *testing.T) {
+	// Use in-memory Badger DB for test
+	opts := badger.DefaultOptions("").WithInMemory(true)
+	db, err := badger.Open(opts)
+	if err != nil {
+		t.Fatalf("Failed to open Badger DB: %v", err)
+	}
+	defer db.Close()
+
+	// Insert a key-value pair
+	err = db.Update(func(txn *badger.Txn) error {
+		return txn.Set([]byte("key1"), []byte("value1"))
+	})
+	if err != nil {
+		t.Fatalf("Failed to insert data: %v", err)
+	}
+
+	// Backup with failing writer should return an error
+	_, err = db.Backup(&failWriter{}, 0)
+	if err == nil {
+		t.Errorf("Expected Backup to fail due to writer error, but got nil")
+	}
+
+	// Backup to normal buffer should succeed
+	buf := &bytes.Buffer{}
+	_, err = db.Backup(buf, 0)
+	if err != nil {
+		t.Errorf("Expected successful backup, got error: %v", err)
+	}
+	if buf.Len() == 0 {
+		t.Errorf("Expected some data in backup, but buffer is empty")
+	}
+}