t.download_test.go

package docxplate

import (
	"context"
	"errors"
	"io"
	"net/http"
	"net/http/httptest"
	"os"
	"testing"
)

type errorTransport struct{}

func (et *errorTransport) RoundTrip(req *http.Request) (*http.Response, error) {
	return nil, errors.New("transport error")
}

func TestDownloadFileInvalidCases(t *testing.T) {
	t.Run("invalid URL", func(t *testing.T) {
		tmpFpath, err := DefaultDownloader.DownloadFile(context.Background(), "::invalid-url")
		if err == nil {
			t.Fatalf("Expected an error, but got nil")
		}
		_ = os.Remove(tmpFpath)
	})

	t.Run("transport error", func(t *testing.T) {
		// Save original transport
		originalTransport := http.DefaultTransport

		// Set custom error transport
		http.DefaultTransport = &errorTransport{}

		// Restore original transport after the test
		defer func() {
			http.DefaultTransport = originalTransport
		}()

		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
		defer server.Close()

		tmpFpath, err := DefaultDownloader.DownloadFile(context.Background(), server.URL)
		// fmt.Println("remove tmp file", tmpFpath, server.URL)
		if err == nil {
			t.Fatalf("Expected an error, but got nil")
		}
		_ = os.Remove(tmpFpath)
	})

	t.Run("non-200 status code", func(t *testing.T) {
		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			w.WriteHeader(http.StatusNotFound)
		}))
		defer server.Close()

		tmpFpath, err := DefaultDownloader.DownloadFile(context.Background(), server.URL)
		if !errors.Is(err, http.ErrMissingFile) {
			t.Fatalf("Expected http.ErrMissingFile, but got: %v", err)
		}
		_ = os.Remove(tmpFpath)
	})

	t.Run("server read error", func(t *testing.T) {
		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			w.Header().Set("Content-Length", "2")
			_, _ = io.WriteString(w, "1") // #nosec G104
		}))
		defer server.Close()

		tmpFpath, err := DefaultDownloader.DownloadFile(context.Background(), server.URL)
		if err == nil {
			t.Fatalf("Expected an error, but got nil")
		}
		_ = os.Remove(tmpFpath)
	})
	//
	// t.Run("create temp file error", func(t *testing.T) {
	// 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
	// 		io.WriteString(w, "test data")
	// 	}))
	// 	defer server.Close()

	// 	// Create a temporary directory with no write permissions
	// 	tempDir, err := os.MkdirTemp("", "downloadFileTest")
	// 	if err != nil {
	// 		t.Fatalf("Failed to create temporary directory: %v", err)
	// 	}
	// 	defer os.RemoveAll(tempDir)

	// 	if err := os.Chmod(tempDir, 0555); err != nil {
	// 		t.Fatalf("Failed to set permissions on temporary directory: %v", err)
	// 	}

	// 	// Temporarily replace os.TempDir function
	// 	originalTempDirFunc := os.TempDir
	// 	os.TempDir = func() string { return tempDir }
	// 	defer func() { os.TempDir = originalTempDirFunc }()

	// 	_, err = downloadFile(server.URL)
	// 	if err == nil {
	// 		t.Fatalf("Expected an error, but got nil")
	// 	}
	// })
}