Merge pull request #177 from icholy/master

Add WithReaderContent PathOp

fs/ops.go

@@ -61,6 +61,23 @@ func WithBytes(raw []byte) PathOp {
 	}
 }
 
+// WithReaderContent copies the reader contents to the file at Path
+func WithReaderContent(r io.Reader) PathOp {
+	return func(path Path) error {
+		if m, ok := path.(manifestFile); ok {
+			m.SetContent(ioutil.NopCloser(r))
+			return nil
+		}
+		f, err := os.OpenFile(path.Path(), os.O_WRONLY, defaultFileMode)
+		if err != nil {
+			return err
+		}
+		_, err = io.Copy(f, r)
+		f.Close()
+		return err
+	}
+}
+
 // AsUser changes ownership of the file system object at Path
 func AsUser(uid, gid int) PathOp {
 	return func(path Path) error {

fs/ops_test.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"strings"
 	"testing"
 	"time"
 
@@ -86,3 +87,14 @@ func TestApply(t *testing.T) {
 		assert.Assert(t, fs.Equal(tmpDir.Path(), expected))
 	})
 }
+
+func TestWithReaderContent(t *testing.T) {
+	content := "this is a test"
+	dir := fs.NewDir(t, t.Name(),
+		fs.WithFile("1", "",
+			fs.WithReaderContent(strings.NewReader(content))),
+	)
+	defer dir.Remove()
+	expected := fs.Expected(t, fs.WithFile("1", content))
+	assert.Assert(t, fs.Equal(dir.Path(), expected))
+}