fs: add tests for CommandReader

internal/fs/fs_reader_command_test.go

@@ -0,0 +1,48 @@
+package fs_test
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"strings"
+	"testing"
+
+	"github.com/restic/restic/internal/fs"
+	"github.com/restic/restic/internal/test"
+)
+
+func TestCommandReaderSuccess(t *testing.T) {
+	reader, err := fs.NewCommandReader(context.TODO(), []string{"true"}, io.Discard)
+	test.OK(t, err)
+
+	_, err = io.Copy(io.Discard, reader)
+	test.OK(t, err)
+
+	test.OK(t, reader.Close())
+}
+
+func TestCommandReaderFail(t *testing.T) {
+	reader, err := fs.NewCommandReader(context.TODO(), []string{"false"}, io.Discard)
+	test.OK(t, err)
+
+	_, err = io.Copy(io.Discard, reader)
+	test.Assert(t, err != nil, "missing error")
+}
+
+func TestCommandReaderInvalid(t *testing.T) {
+	_, err := fs.NewCommandReader(context.TODO(), []string{"w54fy098hj7fy5twijouytfrj098y645wr"}, io.Discard)
+	test.Assert(t, err != nil, "missing error")
+}
+
+func TestCommandReaderOutput(t *testing.T) {
+	reader, err := fs.NewCommandReader(context.TODO(), []string{"echo", "hello world"}, io.Discard)
+	test.OK(t, err)
+
+	var buf bytes.Buffer
+
+	_, err = io.Copy(&buf, reader)
+	test.OK(t, err)
+	test.OK(t, reader.Close())
+
+	test.Equals(t, "hello world", strings.TrimSpace(buf.String()))
+}