tests

writefs/writefs_test.go

@@ -0,0 +1,105 @@
+package writefs
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"testing"
+	"testing/fstest"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestWriteFS(t *testing.T) {
+	data := []byte{0xca, 0xfe, 0xba, 0xbe}
+	roFS := fstest.MapFS{
+		"adir2/afile2": &fstest.MapFile{Data: data},
+	}
+	testfs := testWriteFS{roFS, nil}
+
+	t.Run("OpenFile", func(t *testing.T) {
+		t.Run("defaults to Open for os.O_RDONLY", func(t *testing.T) {
+			f, err := OpenFile(roFS, "adir2/afile2", os.O_RDONLY, fs.FileMode(0))
+			defer f.Close()
+			assert.NoError(t, err)
+
+			buf := make([]byte, len(data))
+			n, err := f.Read(buf)
+			assert.NoError(t, err)
+			assert.Equal(t, n, len(data))
+
+			_, err = f.Write(buf)
+			assert.Error(t, err)
+			assert.True(t, errors.Is(err, fs.ErrInvalid))
+
+			assert.Equal(t, data, buf)
+		})
+		t.Run("return original error for RO open", func(t *testing.T) {
+			f, err := OpenFile(roFS, "notexists", os.O_RDONLY, fs.FileMode(0))
+			assert.True(t, errors.Is(err, fs.ErrNotExist))
+			assert.Nil(t, f)
+		})
+
+		t.Run("return invalid for RO open for write", func(t *testing.T) {
+			f, err := OpenFile(roFS, "notexists", os.O_WRONLY, fs.FileMode(0))
+			assert.True(t, errors.Is(err, fs.ErrInvalid))
+			assert.Nil(t, f)
+		})
+
+		t.Run("return PathError for unvalid paths", func(t *testing.T) {
+			f, err := OpenFile(roFS, "/", os.O_RDONLY, fs.FileMode(0))
+			_, ok := err.(*fs.PathError)
+			assert.True(t, ok)
+			assert.Nil(t, f)
+		})
+	})
+
+	t.Run("WriteFile", func(t *testing.T) {
+
+		n, err := WriteFile(testfs, "adir2/afile2", data)
+		assert.NoError(t, err)
+		assert.Equal(t, n, len(data))
+
+		t.Run("return original error for", func(t *testing.T) {
+			testfs.expectedErr = errors.New("expected")
+			f, err := WriteFile(testfs, "notexists", data)
+			testfs.expectedErr = nil
+			assert.Equal(t, "expected", err.Error())
+			assert.Zero(t, f)
+		})
+	})
+
+}
+
+type testWriteFS struct {
+	fstest.MapFS
+	expectedErr error
+}
+
+type testFileWriter struct {
+}
+
+var _ FileWriter = testFileWriter{}
+
+func (w testFileWriter) Close() error {
+	return nil
+}
+func (w testFileWriter) Write(buf []byte) (int, error) {
+	return len(buf), nil
+}
+func (w testFileWriter) Read(buf []byte) (int, error) {
+	return len(buf), nil
+}
+func (w testFileWriter) Stat() (fs.FileInfo, error) {
+	return nil, nil
+}
+
+// OpenFile ...
+func (fsys testWriteFS) OpenFile(name string, flag int, perm fs.FileMode) (FileWriter, error) {
+	if !fs.ValidPath(name) {
+		return nil, &fs.PathError{}
+	}
+	return testFileWriter{}, fsys.expectedErr
+}
+
+var _ WriteFS = testWriteFS{}