assert that log file is created by writer

writer_test.go

@@ -21,8 +21,11 @@
 package zap
 
 import (
+ "crypto/rand"
+ "encoding/hex"
  "io/ioutil"
  "os"
+ "path/filepath"
  "testing"
 
  "github.com/stretchr/testify/assert"
@@ -44,20 +47,19 @@ func TestOpenNoPaths(t *testing.T) {
 }
 
 func TestOpen(t *testing.T) {
- temp, err := ioutil.TempFile("", "zap-open-test")
- require.NoError(t, err, "Couldn't create a temporary file for test.")
- defer os.Remove(temp.Name())
+ tempName := tempFileName("", "zap-open-test")
+ assert.False(t, fileExists(tempName))
 
  tests := []struct {
  paths []string
  error string
  }{
  {[]string{"stdout"}, ""},
  {[]string{"stderr"}, ""},
- {[]string{temp.Name()}, ""},
+ {[]string{tempName}, ""},
  {[]string{"/foo/bar/baz"}, "open /foo/bar/baz: no such file or directory"},
  {
- paths: []string{"stdout", "/foo/bar/baz", temp.Name(), "/baz/quux"},
+ paths: []string{"stdout", "/foo/bar/baz", tempName, "/baz/quux"},
  error: "open /foo/bar/baz: no such file or directory; open /baz/quux: no such file or directory",
  },
  }
@@ -74,6 +76,9 @@ func TestOpen(t *testing.T) {
  assert.Equal(t, tt.error, err.Error(), "Unexpected error opening paths %v.", tt.paths)
  }
  }
+
+ assert.True(t, fileExists(tempName))
+ os.Remove(tempName)
 }
 
 func TestOpenFails(t *testing.T) {
@@ -123,3 +128,16 @@ func TestCombineWriteSyncers(t *testing.T) {
  w := CombineWriteSyncers(tw)
  w.Write([]byte("test"))
 }
+
+func tempFileName(prefix, suffix string) string {
+ randBytes := make([]byte, 16)
+ rand.Read(randBytes)
+ return filepath.Join(os.TempDir(), prefix+hex.EncodeToString(randBytes)+suffix)
+}
+
+func fileExists(name string) bool {
+ if _, err := os.Stat(name); os.IsNotExist(err) {
+ return false
+ }
+ return true
+}