1 files changed, 28 insertions, 0 deletions
diff --git a/src/cmd/internal/edit/edit_test.go b/src/cmd/internal/edit/edit_test.go
new file mode 100644
index 0000000..0e0c564
--- /dev/null
+++ b/src/cmd/internal/edit/edit_test.go
@@ -0,0 +1,28 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package edit
+
+import "testing"
+
+func TestEdit(t *testing.T) {
+	b := NewBuffer([]byte("0123456789"))
+	b.Insert(8, ",7½,")
+	b.Replace(9, 10, "the-end")
+	b.Insert(10, "!")
+	b.Insert(4, "3.14,")
+	b.Insert(4, "π,")
+	b.Insert(4, "3.15,")
+	b.Replace(3, 4, "three,")
+	want := "012three,3.14,π,3.15,4567,7½,8the-end!"
+
+	s := b.String()
+	if s != want {
+		t.Errorf("b.String() = %q, want %q", s, want)
+	}
+	sb := b.Bytes()
+	if string(sb) != want {
+		t.Errorf("b.Bytes() = %q, want %q", sb, want)
+	}
+}