1 files changed, 55 insertions, 0 deletions
diff --git a/internal/showcase/images_test.go b/internal/showcase/images_test.go
new file mode 100644
index 0000000..c88da00
--- /dev/null
+++ b/internal/showcase/images_test.go
@@ -0,0 +1,55 @@
+package showcase
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+// TestCopyFile_CopiesContent verifies the basic success path still works
+// after copyFile was changed to use a named return so that a destination
+// Close() error can be surfaced without changing the happy-path result.
+func TestCopyFile_CopiesContent(t *testing.T) {
+	t.Parallel()
+
+	dir := t.TempDir()
+	src := filepath.Join(dir, "source.txt")
+	dst := filepath.Join(dir, "dest.txt")
+	want := "hello showcase\n"
+
+	if err := os.WriteFile(src, []byte(want), 0644); err != nil {
+		t.Fatalf("failed to write source file: %v", err)
+	}
+
+	if err := copyFile(src, dst); err != nil {
+		t.Fatalf("copyFile() returned error: %v", err)
+	}
+
+	got, err := os.ReadFile(dst)
+	if err != nil {
+		t.Fatalf("failed to read destination file: %v", err)
+	}
+	if string(got) != want {
+		t.Fatalf("copyFile() wrote %q, want %q", string(got), want)
+	}
+}
+
+// TestCopyFile_MissingSourceReturnsError verifies that a missing source file
+// still produces an error (and never a nil error masked by the deferred
+// destination-close handling) and does not leave a destination file behind.
+func TestCopyFile_MissingSourceReturnsError(t *testing.T) {
+	t.Parallel()
+
+	dir := t.TempDir()
+	src := filepath.Join(dir, "does-not-exist.txt")
+	dst := filepath.Join(dir, "dest.txt")
+
+	err := copyFile(src, dst)
+	if err == nil {
+		t.Fatal("copyFile() with missing source returned nil error, want non-nil")
+	}
+
+	if _, statErr := os.Stat(dst); statErr == nil {
+		t.Fatal("copyFile() with missing source created a destination file, want none")
+	}
+}