1 files changed, 38 insertions, 0 deletions
diff --git a/player-server/internal/service/write_test.go b/player-server/internal/service/write_test.go
index 122ca78..3cf276b 100644
--- a/player-server/internal/service/write_test.go
+++ b/player-server/internal/service/write_test.go
@@ -3,6 +3,8 @@ package service
 import (
 	"context"
 	"errors"
+	"os"
+	"path/filepath"
 	"testing"
 
 	"codeberg.org/snonux/player/internal/clock"
@@ -98,3 +100,39 @@ func TestWriteService_RestoreMedia(t *testing.T) {
 		})
 	}
 }
+
+// TestCopyFile_Success verifies that copyFile creates the destination with
+// the exact contents of the source on a clean run (and returns no error).
+func TestCopyFile_Success(t *testing.T) {
+	dir := t.TempDir()
+	src := filepath.Join(dir, "src.bin")
+	dst := filepath.Join(dir, "dst.bin")
+	payload := []byte("hello copyFile world")
+	if err := os.WriteFile(src, payload, 0o644); err != nil {
+		t.Fatalf("write src: %v", err)
+	}
+	if err := copyFile(src, dst); err != nil {
+		t.Fatalf("copyFile: %v", err)
+	}
+	got, err := os.ReadFile(dst)
+	if err != nil {
+		t.Fatalf("read dst: %v", err)
+	}
+	if string(got) != string(payload) {
+		t.Fatalf("dst contents mismatch: got %q want %q", got, payload)
+	}
+}
+
+// TestCopyFile_MissingSource verifies the source-open error path propagates
+// cleanly (no destination should be created or leaked).
+func TestCopyFile_MissingSource(t *testing.T) {
+	dir := t.TempDir()
+	src := filepath.Join(dir, "does-not-exist.bin")
+	dst := filepath.Join(dir, "dst.bin")
+	if err := copyFile(src, dst); err == nil {
+		t.Fatal("expected error for missing source, got nil")
+	}
+	if _, err := os.Stat(dst); !os.IsNotExist(err) {
+		t.Fatalf("expected dst to not exist, stat err=%v", err)
+	}
+}