test(util): add tests for AtomicWrite function

internal/modules/util/atomicwrite_test.go

@@ -0,0 +1,114 @@
+package util_test
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/hardbox-io/hardbox/internal/modules/util"
+)
+
+func TestAtomicWrite(t *testing.T) {
+	tempDir := t.TempDir()
+
+	t.Run("success_new_file", func(t *testing.T) {
+		path := filepath.Join(tempDir, "new_file.txt")
+		data := []byte("hello world")
+		mode := os.FileMode(0644)
+
+		err := util.AtomicWrite(path, data, mode)
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+
+		info, err := os.Stat(path)
+		if err != nil {
+			t.Fatalf("failed to stat file: %v", err)
+		}
+
+		if info.Mode() != mode {
+			t.Errorf("expected mode %v, got %v", mode, info.Mode())
+		}
+
+		content, err := os.ReadFile(path)
+		if err != nil {
+			t.Fatalf("failed to read file: %v", err)
+		}
+
+		if string(content) != string(data) {
+			t.Errorf("expected content %q, got %q", string(data), string(content))
+		}
+	})
+
+	t.Run("success_overwrite_file", func(t *testing.T) {
+		path := filepath.Join(tempDir, "overwrite_file.txt")
+		initialData := []byte("initial")
+		mode := os.FileMode(0644)
+
+		if err := os.WriteFile(path, initialData, mode); err != nil {
+			t.Fatalf("failed to write initial file: %v", err)
+		}
+
+		newData := []byte("new data")
+		newMode := os.FileMode(0600)
+
+		err := util.AtomicWrite(path, newData, newMode)
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+
+		info, err := os.Stat(path)
+		if err != nil {
+			t.Fatalf("failed to stat file: %v", err)
+		}
+
+		if info.Mode() != newMode {
+			t.Errorf("expected mode %v, got %v", newMode, info.Mode())
+		}
+
+		content, err := os.ReadFile(path)
+		if err != nil {
+			t.Fatalf("failed to read file: %v", err)
+		}
+
+		if string(content) != string(newData) {
+			t.Errorf("expected content %q, got %q", string(newData), string(content))
+		}
+	})
+
+	t.Run("success_creates_parent_directories", func(t *testing.T) {
+		path := filepath.Join(tempDir, "nested", "dir", "file.txt")
+		data := []byte("nested")
+		mode := os.FileMode(0644)
+
+		err := util.AtomicWrite(path, data, mode)
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+
+		content, err := os.ReadFile(path)
+		if err != nil {
+			t.Fatalf("failed to read file: %v", err)
+		}
+
+		if string(content) != string(data) {
+			t.Errorf("expected content %q, got %q", string(data), string(content))
+		}
+	})
+
+	t.Run("error_invalid_directory", func(t *testing.T) {
+		filePath := filepath.Join(tempDir, "is_a_file")
+		if err := os.WriteFile(filePath, []byte("test"), 0644); err != nil {
+			t.Fatalf("failed to write file: %v", err)
+		}
+
+		path := filepath.Join(filePath, "file.txt")
+		data := []byte("test")
+		mode := os.FileMode(0644)
+
+		err := util.AtomicWrite(path, data, mode)
+		if err == nil {
+			t.Fatal("expected error, got nil")
+		}
+	})
+}