internal/testenv: add HasSymlink/MustHaveSymlink

os package and path/filepath package have duplicated code for
checking symlink supports in test code.
This CL tries to simplify such test code.

Change-Id: I0371488337f5e951eca699852daab9ccb16ddd62
Reviewed-on: https://go-review.googlesource.com/27331
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/go/build/deps_test.go b/src/go/build/deps_test.go
index 5b2529129cc5ae4bb794d200f670c0cd85ef4402..caacb14f7e1edc54b3a773b1201a53eb425c4914 100644 (file)
--- a/src/go/build/deps_test.go
+++ b/src/go/build/deps_test.go
@@ -180,7 +180,7 @@ var pkgDeps = map[string][]string{
        "testing":          {"L2", "flag", "fmt", "os", "runtime/debug", "runtime/pprof", "runtime/trace", "time"},
        "testing/iotest":   {"L2", "log"},
        "testing/quick":    {"L2", "flag", "fmt", "reflect"},
-       "internal/testenv": {"L2", "OS", "flag", "testing"},
+       "internal/testenv": {"L2", "OS", "flag", "testing", "syscall"},
 
        // L4 is defined as L3+fmt+log+time, because in general once
        // you're using L3 packages, use of fmt, log, or time is not a big deal.

diff --git a/src/internal/testenv/testenv.go b/src/internal/testenv/testenv.go
index f134f6b04a185f2f8a8844e652da9ec56f4e5e3f..7aff89928e00ca167c14c8a09aa21efceb212ccc 100644 (file)
--- a/src/internal/testenv/testenv.go
+++ b/src/internal/testenv/testenv.go
@@ -127,6 +127,19 @@ func MustHaveExternalNetwork(t *testing.T) {
        }
 }
 
+// HasSymlink reports whether the current system can use os.Symlink.
+func HasSymlink() bool {
+       return hasSymlink()
+}
+
+// MustHaveSymlink reports whether the current system can use os.Symlink.
+// If not, MustHaveSymlink calls t.Skip with an explanation.
+func MustHaveSymlink(t *testing.T) {
+       if !HasSymlink() {
+               t.Skipf("skipping test: cannot make symlinks on %s/%s", runtime.GOOS, runtime.GOARCH)
+       }
+}
+
 var flaky = flag.Bool("flaky", false, "run known-flaky tests too")
 
 func SkipFlaky(t *testing.T, issue int) {

diff --git a/src/internal/testenv/testenv_notwin.go b/src/internal/testenv/testenv_notwin.go
new file mode 100644 (file)
index 0000000..1667302
--- /dev/null
+++ b/src/internal/testenv/testenv_notwin.go
@@ -0,0 +1,20 @@
+// Copyright 2016 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.
+
+// +build !windows
+
+package testenv
+
+import (
+       "runtime"
+)
+
+func hasSymlink() bool {
+       switch runtime.GOOS {
+       case "android", "nacl", "plan9":
+               return false
+       }
+
+       return true
+}

diff --git a/src/internal/testenv/testenv_windows.go b/src/internal/testenv/testenv_windows.go
new file mode 100644 (file)
index 0000000..042c0f2
--- /dev/null
+++ b/src/internal/testenv/testenv_windows.go
@@ -0,0 +1,40 @@
+// Copyright 2016 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 testenv
+
+import (
+       "io/ioutil"
+       "os"
+       "path/filepath"
+       "sync"
+       "syscall"
+)
+
+var symlinkOnce sync.Once
+var winHasSymlink = true
+
+func initWinHasSymlink() {
+       tmpdir, err := ioutil.TempDir("", "symtest")
+       if err != nil {
+               panic("failed to create temp directory: " + err.Error())
+       }
+       defer os.RemoveAll(tmpdir)
+
+       err = os.Symlink("target", filepath.Join(tmpdir, "symlink"))
+       if err != nil {
+               err = err.(*os.LinkError).Err
+               switch err {
+               case syscall.EWINDOWS, syscall.ERROR_PRIVILEGE_NOT_HELD:
+                       winHasSymlink = false
+               }
+       }
+       os.Remove("target")
+}
+
+func hasSymlink() bool {
+       symlinkOnce.Do(initWinHasSymlink)
+
+       return winHasSymlink
+}