os: fix wrong error msg from TestReadClosed

If test would fail, the error message will have wrong error and its
type, because e is used after the failed type assertion.

To fix, use the original err.

While at it,
 - combine the checks for error type and value into one statement;
 - use the standard "got ..., want ..." format.

Fixes: 212d2f82e050 ("os: add ErrClosed, return for use of closed File")
Change-Id: I862a96607b461ab89cce6bed2443b28aa2c16468
Reviewed-on: https://go-review.googlesource.com/c/go/+/428915
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>

diff --git a/src/os/os_test.go b/src/os/os_test.go
index 3f75f28938484e68c73784144c6e00cd1dde78a0..45d3aa6b5e9f9059fd8bd6df1af4ed7969475e3f 100644 (file)
--- a/src/os/os_test.go
+++ b/src/os/os_test.go
@@ -314,12 +314,8 @@ func TestReadClosed(t *testing.T) {
        _, err = file.Read(b)
 
        e, ok := err.(*PathError)
-       if !ok {
-               t.Fatalf("Read: %T(%v), want PathError", e, e)
-       }
-
-       if e.Err != ErrClosed {
-               t.Errorf("Read: %v, want PathError(ErrClosed)", e)
+       if !ok || e.Err != ErrClosed {
+               t.Fatalf("Read: got %T(%v), want %T(%v)", err, err, e, ErrClosed)
        }
 }