Move testutils to pkg

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

pkg/testutil/helpers.go

@@ -0,0 +1,82 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package testutil
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"testing"
+)
+
+var rootEnabled bool
+
+func init() {
+	flag.BoolVar(&rootEnabled, "test.root", false, "enable tests that require root")
+}
+
+// DumpDir prints the contents of the directory to the testing logger.
+//
+// Use this in a defer statement from a test that may allocate and exercise a
+// temporary directory. Immensely useful for sanity checking and debugging
+// failing tests.
+//
+// One should still test that contents are as expected. This is only a visual
+// tool to assist when things don't go your way.
+func DumpDir(t *testing.T, root string) {
+	if err := filepath.Walk(root, func(path string, fi os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if fi.Mode()&os.ModeSymlink != 0 {
+			target, err := os.Readlink(path)
+			if err != nil {
+				return err
+			}
+			t.Log(fi.Mode(), fmt.Sprintf("%10s", ""), path, "->", target)
+		} else if fi.Mode().IsRegular() {
+			p, err := ioutil.ReadFile(path)
+			if err != nil {
+				t.Logf("error reading file: %v", err)
+				return nil
+			}
+
+			if len(p) > 64 { // just display a little bit.
+				p = p[:64]
+			}
+			t.Log(fi.Mode(), fmt.Sprintf("%10d", fi.Size()), path, "[", strconv.Quote(string(p)), "...]")
+		} else {
+			t.Log(fi.Mode(), fmt.Sprintf("%10d", fi.Size()), path)
+		}
+
+		return nil
+	}); err != nil {
+		t.Fatalf("error dumping directory: %v", err)
+	}
+}
+
+// DumpDirOnFailure prints the contents of the directory to the testing logger if
+// the test has failed.
+func DumpDirOnFailure(t *testing.T, root string) {
+	if t.Failed() {
+		DumpDir(t, root)
+	}
+}