Use a helper to be more sure that temp files are cleaned up at exit.

fsutil/fsutil.go

+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// 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 fsutil
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path"
+)
+
+// Create a temporary file with the same semantics as ioutil.TempFile, but
+// ensure that it is unlinked before returning so that it does not persist
+// after the process exits.
+//
+// Warning: this is not production-quality code, and should only be used for
+// testing purposes. In particular, there is a race between creating and
+// unlinking by name.
+func AnonymousFile(dir string) (f *os.File, err error) {
+	// Choose a prefix based on the binary name.
+	prefix := path.Base(os.Args[0])
+
+	// Create the file.
+	f, err = ioutil.TempFile(dir, prefix)
+	if err != nil {
+		err = fmt.Errorf("TempFile: %v", err)
+		return
+	}
+
+	// Unlink it.
+	err = os.Remove(f.Name())
+	if err != nil {
+		err = fmt.Errorf("Remove: %v", err)
+		return
+	}
+
+	return
+}

samples/flushfs/flush_fs_test.go

@@ -19,7 +19,6 @@ import (
 	"encoding/hex"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"path"
 	"runtime"
@@ -27,6 +26,7 @@ import (
 	"testing"
 
 	"github.com/jacobsa/bazilfuse"
+	"github.com/jacobsa/fuse/fsutil"
 	"github.com/jacobsa/fuse/samples"
 	. "github.com/jacobsa/oglematchers"
 	. "github.com/jacobsa/ogletest"
@@ -57,10 +57,10 @@ func (t *flushFSTest) setUp(
 	var err error
 
 	// Set up files to receive flush and fsync reports.
-	t.flushes, err = ioutil.TempFile("", "")
+	t.flushes, err = fsutil.AnonymousFile("")
 	AssertEq(nil, err)
 
-	t.fsyncs, err = ioutil.TempFile("", "")
+	t.fsyncs, err = fsutil.AnonymousFile("")
 	AssertEq(nil, err)
 
 	// Set up test config.
@@ -486,11 +486,8 @@ func (t *NoErrorsTest) Dup2() {
 	AssertEq(nil, err)
 	AssertEq(4, n)
 
-	// Open and unlink some temporary file.
-	t.f2, err = ioutil.TempFile("", "")
-	AssertEq(nil, err)
-
-	err = os.Remove(t.f2.Name())
+	// Create some anonymous temporary file.
+	t.f2, err = fsutil.AnonymousFile("")
 	AssertEq(nil, err)
 
 	// Duplicate the temporary file descriptor on top of the file from our file
@@ -693,11 +690,8 @@ func (t *FlushErrorTest) Dup2() {
 	t.f1, err = os.OpenFile(path.Join(t.Dir, "foo"), os.O_WRONLY, 0)
 	AssertEq(nil, err)
 
-	// Open and unlink some temporary file.
-	t.f2, err = ioutil.TempFile("", "")
-	AssertEq(nil, err)
-
-	err = os.Remove(t.f2.Name())
+	// Create some anonymous temporary file.
+	t.f2, err = fsutil.AnonymousFile("")
 	AssertEq(nil, err)
 
 	// Duplicate the temporary file descriptor on top of the file from our file