[dev.link] all: merge branch 'master' into dev.link

Change-Id: Ic66b5138f3ecd9e9a48d7ab05782297c06e4a5b5

1 files changed, 22 insertions, 0 deletions

diff --git a/src/testing/iotest/example_test.go b/src/testing/iotest/example_test.go
new file mode 100644
index 0000000000..10f6bd38f7
--- /dev/null
+++ b/src/testing/iotest/example_test.go
@@ -0,0 +1,22 @@
+// Copyright 2020 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 iotest_test
+
+import (
+	"errors"
+	"fmt"
+	"testing/iotest"
+)
+
+func ExampleErrReader() {
+	// A reader that always returns a custom error.
+	r := iotest.ErrReader(errors.New("custom error"))
+	n, err := r.Read(nil)
+	fmt.Printf("n:   %d\nerr: %q\n", n, err)
+
+	// Output:
+	// n:   0
+	// err: "custom error"
+}